Peterbilt Y53-6008 User Manual

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O PERAT O R’S

M ANUAL

Medium Duty Models

Cla ss Pa ys

113

221

222

227

Introduction

INTRODUCTION

How to Use This Manual

This Operator's Manual contains useful information for the safe and efficient operation of your Medium Duty vehicle. It also provides information on maintaining your vehicle in the best condition, with an outline for performing safety checks and basic preventive maintenance inspections.

We have tried to present the information you'll need to learn about your vehicle's functions, controls, and operation as clearly as possible. We hope you'll find this manual easy to use. There will be times when you need to take this manual out of your Peterbilt vehicle. When you do, please be sure to return it to the cab when you are finished using it. That way it will be there when you need it the ne xt time or when y ou pass the vehicle on to the next user.

Your Medium Duty may not have all the features or options mentioned in this manual. Therefore, you should pay careful attention to the instructions that pertain to just your vehicle. In

Medium Duty

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addition, if your vehicle is equipped with special equipment or options not discussed in this manual, consult your dealer or the manufacturer of the equipment.

All information contained in this manual is based on the latest production information available at the time of publication. Peterbilt Motors Company reserves the right to make changes at any time without notice.

Safety Signals

A number of alerting messages are in this manual. Please read and follow them. They are there for your protection and information. These messages can help you avoid injury to yourself and your passengers, and can help prevent costly damage to the vehicle.

Key symbols and “signal words” are used to indicate what kind of message is going to follow. Pay special attention to instructions prefaced by symbols and the signal words “WARNING”, “CAUTION”, and “NOTE”. Please do not ignore any of these alerts.

Introduction

WARNING

When you see this word, the message that follo ws is especially vital. It signals a potentially hazardous situation which, if not avoided, could result in an injury or death. This message will tell you what the hazard is, what can happen if you don't heed the warning, and how to avoid it.

WARNING! Never carry additional fuel containers in the vehicle. Such containers, full or empty, may leak, explode or cause a fire in the event of a collision.

CAUTION

Signals a potentially hazardous situation which, if not avoided, could result in property or vehicle damage.

CAUTION: Continuing to operate your vehicle with insufficient oil pressure will cause serious engine damage.

Example:

NOTE

Provides general information: for example, the note could warn you on how to av oid damaging y our vehicle or how to drive the vehicle more efficiently.

Example:

NOTE: Pumping the accelerator will not assist in starting the engine.

Please take the time to read these messages when

you see them, and remember:

WARNING!

Something that could seriously injure you.

CAUTION:

Something that could cause property or vehicle damage.

NOTE:

Useful information.

– 2 – Y53-6008

Medium Duty (R10/06)

Introduction

Vehicle Safety

Make sure your Medium Duty is in top working condition before heading out on the road—it is the responsible driver's duty to do so. Inspect the vehicle according to the “ Check List”, page 13.

WARNING! Do not drink and drive. Your reflexes, perceptions, and judgment can be affected by even a small amount of alcohol. You could have a serious—or even fatal accident—if you drive after drinking. Please do not drink and drive or ride with a driver who has been drinking.

Please remember, this manual is not a training manual. It cannot tell you everything you need to know about driving your Peterbilt vehicle. For that you need a good training program or truck driving school. If you have not been trained, get the proper training before you drive. Only qualified drivers should drive this vehicle.

Every new P eterbilt vehicle is designed to conform to all Federal Motor Vehicle Safety Standards applicable at the time of manufacture. However, even with these safety features, continued safe and reliable operation depends greatly upon regular vehicle maintenance. The vehicle must be operated within the range of its mechanical capabilities and the limits

Driver's

of its load ratings. (See the tire and rim weight ratings information on the Vehicle Certification Label on the driver's door frame.) This vehicle is not approved for off-road operation.

How to Find What You Want

There are several tools built into this manual to help you find what you need quickly and easily. First is the Contents. Located at the front of the manual, this lists the main subjects covered and gives page numbers where you can find these subjects. Use the Contents to find information on a large subject like “Operating the Transmission.”

Cross-references also help you get the in f ormation you need. If some other part of the manual contains further information on the subject you are reading about, a cross-reference will refer you to another page, for example: “See page 46 more information on Safety Restraint Belts.”

Finally, you will find a helpful Index at the back of the manual, listing subjects alphabetically. For example, if you want information on brakes, just look under “Brakes” in the Index. You will find the pages where brakes or related topics are discussed.

, for

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Introduction

A Special Word About Repairs

This is not a repair or workshop manual. Your Peterbilt Dealer's Service Center is the b est place to have your Medium Duty repaired. You can find Peterbilt dealers all over the country with the equipme nt and trained personnel to quickly get you back on the road—and to keep you there.

Your Medium Duty is a complex machine. Anyone attempting repairs on it needs good mechanical training, proper specifications, and proper tools. If you are sure you meet these qualifications, then you can probably perform some repairs yourself. But if you are not an ex perienced mechanic, or do not have the right equipment or training, please leave the repairs to an authorized service facility. They are the ones equipped to do the job safely and correctly.

WARNING! Do not attempt repair work without sufficient training, service manuals, and the proper tools. You could be injured, or you could make your vehicle unsafe. Do only those tasks you are fully qualified to do.

Shop Manuals

If you do decide to do complex repair work, you will need the Medium Duty Maintenance Manual. It contains service procedures, parts information, and supporting material on major components in your vehicle, such as Suspensions, Drivelines, Axles, and the Heater/Air Conditioner.

Listed below are manuals available from your Peterbilt Dealer. (There is a charge for these manuals.) Please provide the Chassis Serial Number when ordering, to be sure you get the correct manuals for your vehicle.

Medium Duty Maintenance Manual

detailed service procedures specifically co mpiled for the components on your vehicle, including: ele ctrical information, maintenance, disassembly, assembly, repairs, overhaul, and troubleshooting procedures. The information contained in this manual is the same used by Peterbilt dealers.

Medium Duty Master Parts Catalog

parts lists with drawings and exploded views for Medium Duty series vehicles.

. This manual includes

. Contains illustrated

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Medium Duty (R10/06)

Introduction

Medium Duty Body Builders' Manual. Contains general guidelines on mechanical and electrical modifications required by your dealer to add bodies, accessories, and special equipment to straight-truck configurations.

WARNING! Modifying your vehicle can make it unsafe. Some modifications can affect your vehicle's electrical sy stem, stability, or other important functions. Before modifying your vehicle, check with your dealer to make sure it can be done safely.

Preventive Maintenance Section

The Preventive Maintenance section (pages 116 – 226) in this manual contains general service information for the operator, such as: lubrication points, making adjustments, and other helpful service information. This is summary information only, used for general maintenance of major components installed on your Medium Duty. For detailed service information see your Medium Duty Maintenance Manual.

When it comes time for major service work, your Peterbilt Dealer or Authorized Service Center will need vehicle and component information. To help you gather this vehicle infor-

mation, see “ tion” on page 226. This section explains vehicle identification and provides space to record model and serial numbers of major components installed on your vehicle.

Consumer Information and Vehicle Identifica-

Additional Sources of Information

Installed Equipment — Operator's Manuals

Major component suppliers to Peterbilt also supply operation manuals specific to their products. Additional manuals and other pieces of literature are included in the glove compartment literature set. Look for information on products such as the engine, driver’ s seat, transmission, axles, tires , and radio. If you are missing these pieces of literature, ask y our P eterbilt Dealer for copies.

Truck Driver's Handbook

Your set of glove compartment literature also contains a copy of the Truck Driver's Handbook, published by the American Trucking Association (ATA). Refer to it for important information on driving your Medium Duty.

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Introduction

Other Sources

Another place to learn more about trucking is from local truck driving schools. Contact one near you to learn about courses they offer.

Federal and state agencies such as the department of licensing also have information you can ask for. The Interstate Commerce Commission can give you information about regulations governing transportation across state lines. Regulations that differ from state to state can be found at various agencies in state governments.

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Medium Duty (R10/06)

Operating Instructions Start–Up

OPERATING INSTRUCTIONS

START–UP

Introduction

The following section covers start-up procedures for getting your Medium Duty ready for the road.

Door Lock and Keys

Doors can be locked from the inside by using the loc k button. Close the door then push the button down to lock. Doors automatically unlock when you open them from inside, and can be locked from the outside with the key only.

As standard equipment, two keys are provided for the doors and ignition. When necessary, additional locks and keys are provided for storage compartments.

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WARNING! To help lessen the chance and/or severity of personal injury in case of an accident, always lock the doors while driving. Along with using the lap shoulder belts properly, locking the doors helps prevent occupants from being thrown from the vehicle.

To lock or unlock the doors from outside the cab:

• Insert the key in the door lock.

• Turn the key toward the rear door frame to lock; forward to unlock.

Cab and Frame Access

The following cab and frame entry/exit procedure recommendations were prepared with personal safety f oremost in mind.

WARNING! Do not jump out of the cab or get into the cab without proper caution. You could slip or fall, possibly suffering a serious injury. You could slip and fall if the steps are wet or icy, or if you step in fuel, oil, or grease.

Start–Up Operating Instructions

To help avoid personal injury due to a slip or fall:

• Use three points of contact (two feet, one hand or one foot, two hands) to grip the steps or handholds whenev er possible and look where you are going.

02611

• Use even more care when steps and handholds (or footwear) are wet, coated with ice, snow, mud, oil, fuel, or grease.

WARNING! Do not step on vehicle components without antiskid surfaces or use components not designed for entry-and-exit use. You could fall and injure yourself if y ou step ont o a slippery surface. For example:

•Do not step onto the surface of a fuel tank. A fuel tank is not a step. The tank surface can get very slippery, and you might not be able to prevent a fall. Use only the steps and handholds provided, not chain hooks, quarter fenders, etc.

•Do not climb onto and off the deck plate—use steps and grab handle provided. If there is no deck plate, or if proper steps and grab handles are not provided, do not climb onto the area behind the cab.

•Keep steps clean. Clean any fuel, oil, or grease off the steps before entering the cab or accessing the deck plate.

WARNING! Always reinstall the battery compartment cover (step) before entering the cab. Without the battery cover you could slip and fall, resulting in possible injury to yourself.

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Medium Duty (R10/06)

Operating Instructions Start–Up

NOTE: Any alteration (adding bulkheads, headache racks, tool boxes, etc.) behind the cab tha t affects the utilization of grab handles, deck plates, or frame access steps installed by Peterbilt should comply with Federal Motor Carrier Safety Regulation 399.

Hood Hold Downs and Tilt

The hood is locked in its closed position by an exter nal latch on each side. These latches serve as hold downs and keep the hood from opening unexpectedly.

CAUTION: If you do not latch the hood securely, it could open during operation and cause vehicle damage. Be sure to latch the hood securely before moving the vehicle.

WARNING! A pivoting hood could hurt someone or be damaged itself. Before opening or closing the hood, be sure there are no people or objects in the way.

To open the hood, unlatch both of the hood hold downs.

UNLATCHED

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Start–Up Operating Instructions

Put one hand on the hood handle (just above the Peterbilt emblem), one foot on the bumper, and one foot on the ground. Tilt the hood forward until you hear it “lock”.

02609-1, -2

WARNING! If the hood falls, anyone under it could be injured. Always make sure the lock is engaged to keep your hood open any time anyone gets under the hood for any reason. Never work under the hood unless the hood safety lock is engaged.

To close the hood, you must first releas e the hood safety lock.

WARNING! Before closing the hood, be sure the area is clear—no people or objects are in the way.

CAUTION: To avoid hood damage when closing the hood, firmly squeeze the handle to release the hold-open lock.

HOOD HOLD-OPEN RELEASE HANDLE

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Medium Duty (R10/06)

Operating Instructions Start–Up

After lowering the hood, latch the hood closed with the hold downs.

WARNING! If the hood is not latched securely, it could open during operation and cause an accident. Be sure the hood is latched securely before moving the vehicle.

LATCHED

Safe Vehicle Operation

For your safety, as well as those around you, be a responsible driver:

• If you drink, do not drive.

• Do not drive if you are tired, ill, or under emotional stress.

Much has gone into the manufacturing of your Medium Duty, including advanced engineering techniques, rigid quality control, and demanding inspections. These manufacturing processes will be enhanced by you—the safe driver—who:

• knows and understands how to operate the vehicle and all its controls

• maintains the vehicle properly

• uses driving skills wisely

For more information, refer to Department of Transportation Regulation 392.7, which states that interstat e commercial motor vehicles are not to be driven unless the driver is sure that certain parts and accessories are in working order.

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Start–Up Operating Instructions

WARNING! Do not drink and drive. Your reflexes, perceptions, and judgment can be affected by even a small amount of alcohol. You could have a serious—even fatal—accident if you drive after drinking. Please do not drink and drive or ride with a driver who’s been drinking.

•The use of alcohol, drugs, and certain medications will seriously impair perception, reactions, and driving ability. These circumstances can substantially increase the risk of an accident and serious personal injury.

Vehicle Loading

Compare your vehicle's load capacity with the total load you are carrying. If ad justments need to be made, make them— do not drive an overloaded vehicle. If you are overloaded or your load has shifted, your vehicle may be unsafe to drive.

WARNING! Do not exceed the specified load rating. Overloading can result in loss o f vehicle control and serious personal injury, either by causing component failures or by affecting vehicle handling. Exceeding load ratings can also shorten the service life of the vehicle.

•The components of your vehicle are designed to provide satisfactory service if the vehicle is not loaded in excess of either the gross vehicle weight rating (GVWR), or the maximum front an d rear gross axle weight ratings (GAWRs). (Axle weight ratings are listed on the driver's door edge.)

Here are some definitions of weight you should know:

GVWR:

MAXIMUM WEIGHT your vehicle is allowed to carry, including the weight of the empty vehicle, loading platform, occupants, fuel, and any load. Never exceed the GVWR of your vehicle.

GCW:

Weight (GCW), of your vehicle and its load: tractor, plus trailer(s), plus cargo.

is the Gross Vehicle Weight Rating. This is the

is the actual combined weight, or Gross Combination

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Medium Duty (R10/06)

Operating Instructions Start–Up

GAWR: is the Gross Axle Weight Rating. This is the total weight that one axle is designed to transmit to the ground. You will find this number listed on the driver's door edge.

Load Distribution: be sure any load you carry is distributed so that no axle has to support more than its GAWR.

WARNING! An unevenly distributed load or a load too heavy over one axle can affect the braking and handling of your vehicle, which could result in an accident. Even if your load is under the legal limits, be sure it is distributed evenly.

Emergency Equipment

It is good practice to carry an emergency equipment kit in your vehicle. One da y, if you hav e a roadside emergency, you will be glad the following items are with you:

• window scraper

• snow brush

• container or bag of sand or salt

• emergency light

•small shovel

• first aid kit

• fire extinguisher

Driver's Check List

To keep your Medium Duty in top shape and maintain a high level of safety for you, your passengers, and your load, make a thorough inspection every day before you drive. You will save maintenance time later, and the safety checks could help prevent a serious accident. Please remember, too, that the Federal law requires a pre-trip inspection and so do commercial trucking companies.

You are not expected to become a professional mechanic. The purpose of your inspections is to find anything that might interfere with the safe and efficient transportation of yourself, any passengers, and your load. If you do find something wrong and cannot fix it yourself, have an Authorized Service Center or qualified mechanic repair your vehicle right away.

The following operations are to be perfor med by the driver. Performing these checks and following the maintenance procedures in this manual will help keep your Medium Duty running properly.

Approaching Your Vehicle

• Check the overall appearance and condition. Are windows, mirrors, and lights clean and unobstructed?

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Start–Up Operating Instructions

• Check beneath the vehicle. Are th ere signs of fuel, oil, or water leaks?

• Check for damaged, loose, or missing parts. Are there parts showing signs of excessive wear or lack of lubrication? Have a qualified mechanic examine any questionable items and repair them without delay.

• Check your load. Is it secured properly?

Daily Checks

NOTE: The following items (Engine Compartment, Chassis and Cab, and Prestart Checks) should be checked daily, as a minimum. They are in addition to, not in place of, federal motor Carrier Safety Regulations. These regulations may be purchased by writing to:

Superintendent of Documents U.S. Government Printing Office Washington, DC 20402

Engine Compartment Checks — Daily

1. Engine Fluid Levels—add more if necessary.

• Engine oil

• Coolant (check while engine is cold)

• Power steering fluid level

• If your truck has hydraulic brakes, check the fluid level in the master cylinder reservoir. See page 154 for more information.

2. Engine Belt—check tension and condition of belts. This is important to ensure proper air compressor and engine operation.

• Measure the belt tension at the longest span of the belt. See page 142 ing belt tension.

NOTE: Deflection should be one belt thickness for each foot distance between the pulley centers.

• If breaks or tears are found, the belt should be replaced before operating the vehicle.

3. Fuel Filter/Water Separator Draining—check and drain. Depending on the fuel storage facility, more frequent draining may be required.

4. Windshield washer reservoir fluid level—fill if necessary.

5. Hood closed before entering cab. Is it latched properly?

Chassis and Cab Checks — Daily

Before entering the cab and operating the vehicle, check the following equipment for proper maintenance:

for further information on check-

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Medium Duty (R10/06)

Operating Instructions Start–Up

1. Lights—do headlights, turn signals, emergency flashers, and exterior lamps function and are they clean and adjusted properly?

2. Windows and Mirrors—are they clean and adjusted properly?

3. Tires and Wheels—are they inflated properly? Are all wheel cap nuts in place and torqued properly—tighten if necessary. Check front wheel bearing oil levels. Inspect all tires and wheels for damage—correct if found.

4. Suspension—check for loose or missing fasteners. Check damage to springs or other suspension parts.

5. Brake Components—check lines, linkages, chambers, and brake operation.

6. If your truck has hydraulic brakes, check:

• the brake system for leaks

• hydraulic lines for cracks or kinks

• calipers for leaks

7. Air System—are there leaks?

• Air Tanks—drain water from all air tanks. Make sure the drain cocks are closed. This procedure is also required for air suspension tanks equipped with automatic drain valves.

• See page 72 System.”

for further details on “Using the Brake

8. Steps and Handholds—check for worn surfaces and loose or missing fasteners.

9. Fluid Tanks—check underneath the vehicle for signs of fluid leaks. If any are found, correct before operating the vehicle.

10. Fuel Tank Caps—are they secure?

WARNING! Diesel fuel in the presence of an ignition source (such as a cigarette) could cause an explosion. You could be seriously injured. A mixture of gasoline or alcohol with diesel fuel increases this risk of explosion.

•Do not remove a fuel tank cap near an open flame.

•Use only the fuel and/or additives recommended for your engine.

•See page 114

11. Trailer Connections (Tractor)—are they secure and the lines clear? If they are not being used, are they stored properly?

• Is the trailer spare wheel secure and inflated?

• Is the landing gear up and the handle secured?

12. Check the fifth wheel. Is the kingpin locked?

• Is the sliding fifth wheel locked?

for more information.

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Start–Up Operating Instructions

Prestart — Daily

1. Seat—adjust the seat for easy reach of controls.

2. If your vehicle is equipped with an adjustable steering column, adjust the steering wheel to a comfortable position.

3. Mirrors—check and readjust mirrors if necessary.

4. Lights—turn ignition key to the IGN & ACC position and check for warning lights and buzzer. Check operation of turn signals and emergency lights.

5. Instruments—check all instruments.

6. Windshield—check operation of windshield wipers and washers.

7. Horn—check operation of horn.

8. Check fire extinguisher charge and road emergency kit.

9. Fuel—check fuel. Is there enough fuel?

10. Seat Belts—fasten and adjust safety restraint belts

Weekly Operations

1. Battery—check battery and terminals.

2. Wheel Cap Nuts—are they all in place and torqued properly—tighten if necessary. See “ Page 173.

3. Other Controls and Wiring—check for condition and adjustment.

4. Steering Components—check pitman arm, draglink, and power steering hoses, etc., for loose, broken, or missing parts.

5. Other Engine Compartment Checks

• Check condition and fastening of engine belt, hoses , clamps, and radiator.

• Check the air cleaner, muffler, and exhaust pipes. Are they tight and secure?

• After Engine Warm-up

– Automatic Transmission—check fluid level in the

automatic transmission oil (if equipped).

Wheel Cap Nut Torque,”

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Medium Duty (R10/06)

Operating Instructions Start–Up

02599A

DASH INSTRUMENT PANEL

1 Headlight 6 Oil Pressure 11 Voltmeter (option) 2 Clearance Lights 7 Water Temperature 12 Air Pressure 3 Windshield Washer/Wiper 8 Speedometer 13 Transmission Temperature (option) 4 Panel Lights 9 Air Cleaner Restriction/Filter (option) 14 Warning Lamp Cluster 5 Tachometer 10 Fuel 15 Ignition Switch

02595-1A

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Instruments and Controls Operating Instructions

INSTRUMENTS AND CONTROLS

Introduction

Your Medium Duty dashboard is shown on the opposite page.

The dash includes standard gauges and switches. Your vehicle may come with all or some of the switches and gauges discussed here. The location of switches on the dash will vary depending on the options ordered and how your vehicle was configured.

For your convenience, all gauges and their corresponding page numbers are listed here, see “ to the page listed to learn what each gauge does and how it should be used.

Index of Gauges”. Refer

Instrument Index

Table 1 Index of Gauges

GAUGE REFERENCE PAGE

Tachometer 22 Engine Oil Pressure 25 Engine Coolant Temperature 23 Speedometer 21 Air Cleaner Restriction (option) 30 Fuel Level 28 Voltmeter (option) 29 Air System Pressure 26 Transmission Temperature (option) 29

Warning Lights and Buzzer

Many vehicle systems are linked to the instruments on your instrument panel. Warning lights (in each instrument) may indicate something is wrong with one of the many vehicle systems. Check the lights frequently, and respond properly as soon as a light or buzzer comes on.

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Medium Duty (R10/06)

Operating Instructions Instruments and Controls

WARNING LAMP MODULE

Medium Duty

HIGH

BEAM

FIFTH WHEEL

LOAD

LIGHT

STOP

ENGINE

CHECK

ENGINE

CRUISE

CONTROL

DIFF LOCK

SPOT

LIGHT

WAIT

START

ENGINE

OIL

BRAKE

AIR

MIRROR

HEAT

LOW

WATER

FAN

ABS

VEHICLE WITH AIR BRAKES

CHECK TRANS

OIL

BRAKE

MIRROR

HEAT

LOW

WATER

ENGINE

FAN

HIGH BEAM

FIFTH WHEEL

LOAD LIGHT

STOP

ENGINE

CHECK

ENGINE

CRUISE

CONTROL

PARK

RANGE

SPOT

LIGHT

INHIBIT

VEHICLE WITH HYDRAULIC BRAKES

(R10/06) Y53-6008 – 19 –

Instruments and Controls Operating Instructions

Self Test

When you turn on your ignition, the following warning lights will turn on for 3 - 5 seconds, as a test to let you know they are working.

Diff Lock Trailer ABS Water Temp Left Turn Mirror Heat Load Light Brake Air (or Brake *) High Beam Fifth Wheel Right Turn Oil Pressure Engine Fan ABS Park * * Vehicle with hydraulic brakes only

WARNING! Do not ignore a warning light or buzzer. These signals tell you some thing is wrong with your vehicle. It could be a failure in an important system, such as the brakes, which could lead to an accident. Have the appropriate system checked immediately.

The buzzer will sound continuously as long as:

• Engine temperature is above the specified range

• Air pressure to the service brakes is low

• Engine oil pressure is low

• There is a problem in the hydraulic brake system

If the buzzer sounds while driving, or if a light comes on, do the following:

1. Slow down carefully.

2. Move a safe distance off the road and stop.

3. Set the parking brake. (See Pages 68 mission shifting and parking brake information.)

4. If the engine is overheating do not turn it off, see page 23; otherwise, for other conditions turn the engine OFF.

5. Turn on the emergency flasher and use other warning devices to alert other motorists.

and 74 for trans-

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Medium Duty (R10/06)

Operating Instructions Instruments and Controls

WARNING! Do not operate the vehicle if the BRAKE warning lamp illuminates or the buzzer sounds. The vehicle should not be oper ated until the system is repaired. Failure to respond to a brake warning (lamp or buzzer) could result in an accident and/or severe injury.

Speedometer and Odometer

The speedometer indicates the vehicle speed in miles per hour (MPH) and in kilometers per hour (km/h).

The odometer records the distance traveled by the vehicle, either in miles or kilometers, depending on which unit is installed in the vehicle.

Speedometer (MPH-km/h)

02587

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Instruments and Controls Operating Instructions

Tachometer

The vehicle's tachometer measures the engine speed in revolutions–per–minute (rpm). Watching the tachometer is important to driving efficiently. It will let you match driving speed and gear selection to the operating range of your engine. If the engine speed gets too high, you can select a higher gear to lower the rpm's. If the engine speed drops too low, you can select a lower gear to raise the rpms. See page 99 for further instructions on driving techniques and using the

HOURMETER

(OPTION)

Tachometer

02586

tachometer.

• To avoid engine damage, do not let the pointer exceed maximum governed speed.

• When driving downhill, shift to a lower gear and use the service brake, keeping the engine speed below the maximum governed speed.

The hour meter (option) records the time in hours the engine is operating.

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Medium Duty (R10/06)

Operating Instructions Instruments and Controls

Coolant (Water) Temperature Gauge

The water temperature gauge shows the temperature of the engine coolant. Under normal operating conditions the water temperature gauge should register between 165 and 205°F (74 and 90°C). Under certain conditions, somewhat higher temperatures may be acceptable. The maximum allowable temperature is 210°F (99°C) with the cooling system pressurized, except for cer tain special engines. Check the engine manual to be sure.

02580

Water Temperature Gauge

Engine Overheating

The cooling system may ov erheat if the coolant level is below normal or if there is sudden loss of coolant, such as a split hose. The system may also temporarily overheat during severe operating conditions such as:

• Climbing a long hill on a hot day

• Stopping after high–speed driving

If the Engine Coolant Temperature (“WATER”) warning light comes on and the audible alarm sounds showing an overheat condition, or if you have an y other re ason to suspect the engine may be overheating, DON'T TURN OFF THE ENGINE unless the “LOW WATER” warning light also comes on, indicating a loss of coolant. Instead, follow these steps:

A. Reduce engine speed or stop. When stopped, place the

transmission in Neutral and set the parking brake. See Pages 68

and 74 for transmission shifting and parking

brake information.

B. Check to ensure that the oil pressure gauge reads nor-

mal.

C. Increase the engine speed to about one–half of full oper-

ating speed, or 1100 to 1200 rpm, maximum.

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Instruments and Controls Operating Instructions

D . Return the engine speed to normal idle after two or three

minutes.

E. Monitor the engine temperature. After the temperature

returns to normal, allow the engine to idle 3 to 5 minutes before shutting it off. This allows the engine to cool gradually and uniformly.

• If the overheating came from severe operating conditions, the temperature should have cooled by this time.

FILL

02604

Coolant Expansion Tank

F. Check the level of coolant in the coolant expansion tank

(engine compartment, right side.)

WARNING! Removing the radiator fill cap while the engine is hot can be dangerous. Never remove the caps of the expansion tank while the engine is still hot; you could be badly burned.

•Scalding steam and fluid under pressure may escape and cause serious personal injuries.

•Wait until the coolant temperature is below 122°F (50°C).

•Protect your face, hands, and arms by covering the cap with a large, thick rag to protect against escaping fluid and steam.

WARNING! Carefully and slowly turn cap one turn to allow excess pressure to escape, then push down and turn for final removal.

G. See page 143

for instructions on checking and filling the

coolant expansion tank.

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Medium Duty (R10/06)

Operating Instructions Instruments and Controls

WARNING! To reduce the chance of personal injury and/or vehicle damage due to engine overheating, never leave the engine idling without an alert driver present. If the engine should overheat, as indicated by the engine coolant temperature light, immediate action is required to correct the condition. Continued unattended operation of the engine, even for a short time, may result in serious engine damage or a fire.

For further details on engine operation, see the Engine Operation and Maintenance Manual in the glove compartment of

your vehicle.

Engine Oil Pressure Gauge

It is important to maintain oil p ressure within acceptable limits. If oil pressure drops below the minimum psi a Red Warning Lamp on the oil pressure gauge and the Stop Engine Warning Lamp will come ON.

For further information on engine oil and normal operating pressures, see the Engine Operation and Maintenance Man- ual.

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02585

Engine Oil Pressure Gauge

CAUTION: Continuing to operate your vehicle with insufficient oil pressure will cause serious engine damage.

• If the oil pressure fails to rise within 10 seconds after the engine starts, stop the engine and determine the cause.

• Check the engine manufacturer's manual for the correct oil pressure ranges for your vehic le's engine.

• If the oil pressure suddenly drops, or the audible alarm and engine oil pressure warning light come on while driving, do the following:

1. Slow down carefully.

2. Move a safe distance off the road and stop.

Instruments and Controls Operating Instructions

3. Place the transmission in park and set the parking brake. (See Pages 68

and 74 for transmission

shifting and parking brake information.)

4. Turn OFF the engine.

5. Turn ON the emergency flasher and use other

FRONT

SECONDARY

SERVICE

CIRCUIT

(WHITE)

warning devices to alert other motorists.

6. Wait a few minutes to allow oil to drain into the engine oil pan, and then check the oil level. (See page 139

7. Add oil if necessary. If the problem persists, contact an Authorized Service Center.

For further information on operating your engine properly, see page 58

for details on checking oil level.)

02581

Dual Air Pressure Gauge (Air Reservoir)

REAR PRIMARY SERVICE

CIRCUIT

(ORANGE)

If the pressure in either or both circuits is too low for normal

Dual Air Pressure Gauge (Air Reservoir)

The dual air pressure gauge indicates the amount of air pressure in the brake system in pounds per square inch (psi). The WHITE pointer shows the front (secondary service) reservoir air pressure, and the ORANGE pointer indicates pressure in the rear (primary service) reservoir.

brake operation (below 64 psi), a warning light in the panel will glow and the audible alarm will sound.

WARNING! If the light and alarm do not turn off at start-up, do not try to drive the vehicle until the problem is found and fixed.

– 26 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Instruments and Controls

WARNING! If the air pressure falls below 60 psi (414 kPa) the spring brakes may stop the vehicle abruptly, which could result in an accident and/ or injuries. Observe the warning light in the panel. If it comes on, do not continue to drive the vehicle until it has been properly repaired or serviced.

WARNING! The air pressure warning light and the audible alarm indicate a dangerous situation: there is not enough air pressure in the reservoirs for repeated braking and the brake system has failed. Without the use of your service brakes, your spring brakes could suddenly apply. This could cause a wheel lock-up, loss of control, or over-take by following vehicles. You could be in an accident and severely injured.

•Bring the vehicle to a safe stop right awa y, while you still have control of the vehicle.

Air Loss Emergency Procedure

1. Slow down carefully.

2. Move a safe distance off the road and stop.

3. Place the transmission in park and set the parking brake. (See Pages 68 ing brake information.)

4. Turn OFF the engine.

5. Turn ON the emergency flasher (See “ Flasher Switch” on page 55) and use other warning devices to alert other motorists.

and 74 for transmission shifting and park-

Emergency

Medium Duty

(R10/06) Y53-6008 – 27 –

Instruments and Controls Operating Instructions

Fuel Gauge

The fuel gauge shows the approximate amount of fuel in the fuel tanks. Besides empty and full, the gauge also indicates 1/4, 1/2 and 3/4 of total fuel capacity.

02584

Fuel Gauge

Your truck has one main fuel tank and up to four optional tanks. The fuel gauge shows the total amount of fuel. It is a good idea to keep fuel tanks at least half–full; otherwise, water that condenses in an empty tank will contaminate the fuel and could damage the engine.

WARNING! Do not carry additional fuel containers in your vehicle. Fuel container s, eit her full or empty, may leak, explode, and cause or feed a fire. Do not carry extra fuel containe rs, even empty ones are dangerous.

WARNING! Do not remove a fuel tank cap near an open flame. Hot fuel vapors are combustible and can cause an explosion or fire resulting in injury or death.

See page 114

for more information.

– 28 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Instruments and Controls

Voltmeter (option)

The voltmeter shows the voltage your vehicle's electrical system is putting out. Normally, it should show 10 to 16 volts. If voltage drops, have the electrical system checked.

02582

Voltmeter

Transmission Temperature Gauge (option)

Your vehicle may be equipped with a transmission temperature gauge. It indicates the temperature of the oil in your transmission. Watch this gauge to know when your tr ansmission is overheating. If it is, have it checked by an Authorized Service Center.

02579

Transmission Temperature Gauge

CAUTION: Maximum allowable transmission temperature may vary, depending upon your transmission and type of lubricant. Check your transmission Owner's Manual.

Medium Duty

(R10/06) Y53-6008 – 29 –

Instruments and Controls Operating Instructions

CAUTION: Do not continue to operate with the Air Filter Restriction Gauge reading 25 in. (start of red area). It could lead to damage to the

RED

CAUTION

AREA

engine. Inspect the filter and replace if necessary.

Holes in the paper element render an air cleaner useless and may cause the Air Filter Restriction Gauge to give a false reading, even if the element is clogged. Replace the element if it is damaged. See page 167

for information on Air Filter

Replacement.

02583

Air Filter Restriction Indicator

Headlight Switch

The headlights are controlled by a toggle

Air Filter Restriction Indicator (option)

This gauge indicates the condition of the engine air cleaner and is measured by inches of water . A clean filter should register 7 in. of water and a filter whose life is over will register approximately 25 in.

For High Beam operation see page 54

switch on the left instrument panel. See page 17

. When the headlights are ON, the dash lights, side, and tail lamps are also on.

– 30 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Instruments and Controls

Daytime Running Lights (option)

On vehicles equipped with the Daytime Running Light (DRL) system, the low beam headlights are turned ON automatically at reduced brightness (to conserve headlamp life).

Three controls (or conditions) will affect whether the system is ON or OFF:

• headlight switch

• engine on

• parking brake

If the headlight switch is turned OFF, the DRL system engages automatically after the engine starts and you release the parking brake. If the headlight switch is ON, the DRL system is overridden, and headlights operate normally.

WARNING! Do not use daytime running lights (DRL) during periods of darkness or reduced visibility. Do not use DRL as a substitute for headlights or other lights during operations that require lighting of your vehicle. Doing so could lead to an injury accident.

Panel Lights

The Panel Lights knob lets you vary the brightness of your instrument panel lights. The knob is located on the left instrument panel. See page 17

To Operate the Panel Lights:

Turn on either the headlights, clearance lights, or fog/driving lights.

To brighten the instrument panel lights, tur n the knob clockwise (to the right).

To dim the instrument lights or to turn them off, turn the knob counterclockwise (to the left).

ID and Clearance Lights

A toggle switch controls the amber lights on top of your cab , plus any additional lights that

were installed on the front, sides, and rear of your vehicle. The switch is located on the left instrument panel, and is labeled CL LPS. See page 17

Medium Duty

(R10/06) Y53-6008 – 31 –

Instruments and Controls Operating Instructions

Windshield Wipers/Washer

NOTE: The ignition key must be turned to ACC or IGN & ACC for the wiper/washer switch to operate.

A five-position windshield wiper switch controls the wipers and washer. To turn ON the wipers, turn the knob clockwise.

• For intermittent operation turn to the 1st and 2nd positions; for continuous operation advance to the 3rd and 4th positions.

• The final option activates the washer cycle. To wash the windshield, push knob IN and release. Hold knob IN to extend washing cycle. After one to three wipes (depending on how long you hold the switch in) the wipers will shut off automatically.

The windshield washer tank is located inside the engine compartment below the radiator expansion tank. See “

Washer Reservoir” on page 201. Check the windshield

washing fluid level weekly. If necessary, fill to top.

CAUTION: If the electric pump is operated for a long period (more than 15 seconds) with a dry reservoir, the pump rotor may be damaged.

PUSH IN

FOR

WASHER

Windshield wipers/washer switch

POSITION MODE

0OFF 1 Intermittent Range: long delay 2 Intermittent Range: Short delay 3 Low Speed 4 High Speed

Wiper/washer (push in)

– 32 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Instruments and Controls

WARNING! Do not drive with worn or dirty wiper blades. They can reduce visibility, making driving hazardous. Clean the blades regularly to remove road film and wax build-up. Use an alcohol-based cleaning solution and a lint-free cloth, and wipe along the blades.

WINDSHIELD

WASHER FLUID

TANK

02391

Windshield Washer Fluid Tank

Clean all inside and outside windows regularly. Use an alcohol-based cleaning solution and wipe dry with e ither a lintfree or a chamois cloth. Avoid running the wiper blades over a dry windshield to prevent scratching the glass. Spray on washer fluid first. A scratched windshield will reduce visibility.

Ignition Key Switch

The engine ignition key switch (located to the left of the steering column) has four positions: ACC (Accessories), OFF, IGN & ACC, and IGN & START.

OFF: In this position all accessories are OFF (except those listed below) and you can remove the key.

• The following lights and accessories have power when the key is in the OFF position:

- brake lights - marker lamps

- cigarette lighter - headlights

- tail lights - radio station memory

- horn - instrument lights

- emergency hazard flasher

- dome and courtesy lamps (on doors)

- auxiliary Power/Body or Trailer

NOTE: In the OFF position, fuel is cut off by a solenoid valve located on the left side of the engine, near the ejection pump.

ACC (Accessory): With the key in this position you can play the radio, defrost mirrors (if equipped with mirror heat) or use other accessories.

Medium Duty

(R10/06) Y53-6008 – 33 –

Instruments and Controls Operating Instructions

IGN & ACC: In this position, all circuits are energized. Panel warning lights will light and the buzzer will sound until (1) the engine is started, (2) nor mal oil operating pressure is reached, and (3) air brake system pressure is above 64 psi (441 kPa). In this position, the ignition key cannot be removed.

IGN & START: Turn the key to this position to start your engine: it energizes the starter and retracts the solenoid valve to allow fuel supply to the engine. See page 59

for

details on starting the engine.

Parking Brake

Before you leave the cab, apply all parking brakes.

- for vehicles with air brakes:

1. Apply all parking brakes. Pull out the Yellow Parking Brake Control knob (1) located on the dash. In tractors, the Red (octagon-shaped) Trailer Air Supply Control knob (2) will automatically pop out.

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02391-1

Full Truck Parking Brake Valve

WARNING! Do not leave the cab without applying the parking brake. The truck could roll and cause an injury accident. Always apply the parking brake before you leave the cab.

– 34 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Instruments and Controls

Using the Brake System” on page 72 for more informa-

See “

(2) Trailer Air Supply Control (Red)

(1) Parking Brake Control (Yellow)

tion.

- for vehicles with hydraulic brakes:

The parking brake consists of a driveline drum brake actuated by a lever and cable. The hand lever, mounted on the vehicle's cab floor, pulls or releases the cable controlling the brake. Pulling upward on the parking brake lever pulls the

02394

Combination (Tractor/Trailer) Parking Brake Control Valves

cable and expands the driveline brak e shoes outward against the driveline brake drum.

The driveline brake is disengaged by pushing the handle

2. Shift the transmission into its PARK position. (See Pages and 74 for transmission shifting and parking brake

68 information.)

3. Turn the key to OFF.

4. Remove the key.

downward to its lowest position.

NOTE: Failure to fully release the parking brake can cause the brakes to overheat.

CAUTION: Unless it is an emergency, do not pull

upward on the parking brake lever while the WARNING! Do not pull out the parking brake valve while the vehicle is moving. Stopping with the parking brake controls can cause a sudden wheel lock-up, loss of control, or over-take by

vehicle is moving. Attempting to stop with the

parking brake could cause damage to the drive-

line, transmission, or the parking brake mecha-

nism itself. following vehicles. You could be severely injured.

Medium Duty

(R10/06) Y53-6008 – 35 –

Instruments and Controls Operating Instructions

Using the Parking Brake

1. Come to a complete stop.

PARKING BRAKE LEVER

ENGAGE

DISENGAGE

2. Apply the parking brake. Pull upward on the parking brake lever until it reaches an over (top) center position. (The PARK light on the dash will come on.)

NOTE: Ensure the lever is over center. The light will come on prior to brake being fully applied.

CONTROL

STOP

ENGINE

CHECK

ENGINE

CRUISE

PARK

SPOT LIGHT

PARKING BRAKE INDICATOR

3. Shift the transmission into NEUTRAL position:

4. Turn the key OFF.

5. Remove the key.

6. If you are parked on a grade, always block the wheels.

– 36 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Instruments and Controls

Cruise Control Switch

02901

WARNING! Do not operate the cruise control when operating on road surfaces with poor traction (wet, icy, or snow covered roads) or in heavy traffic. Accelerations caused by the normal operation of the cruise control could cause you to lose control of the vehicle resulting in an injury accident.

The master switch turns the cruise control ON or OFF. The second switch allows you to SET the desired speed or RESUME the desired speed after the cruise control function has been interrupted.

See page 65 for instructions on how to use the cruise control.

Hand Throttle Control

Your vehicle may be equipped with a hand throttle. It is located on the floor, to the left of the driver's seat. It can be especially helpful in cold weather to keep your engine running above idle speed when you leav e the v ehicle briefly. See page 64

for more information on idling your engine safely.

WARNING! Do not use the hand throttle control for cruise control or to control your road speed. It could cause an accident and you could be seriously injured. Always disengage the hand throttle before driving the vehicle.

Medium Duty

(R10/06) Y53-6008 – 37 –

Heating and Air Conditioning Operating Instructions

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HEATING AND AIR CONDITIONING

Introduction

WARNING! Do not drive with your visibility reduced by fog, condensation, or frost on the windshield. Your view may be obscured, which could result in an injury accident. For clear visibility and safe driving it is extremely important for you to follow the instructions on the use of the ventilation/heating and defogging/defrosting system. If in doubt, consult your dealer. Maximum heating output and fast defrosting can be obtained only after the engine has reached operating temperature.

Internal air circulation control is provided by three sets of outlets:

• Front outlets on the dashboard panel, with directional louvers

• Floor outlets under the dashboard

• Window defrost vents on the dashboard

Heater and Air Conditioner Controls

WARNING! Excessive heat may cause the pressurized components of the air conditioning system to explode. Never weld, solder, steam clean, or use a blow torch near any part of the air conditioning system.

•If a refrigerant leak develops in the presence of excessive heat or an open flame, hazardous gases may be generated. These gases may cause unconsciousness or death. If you become

02593

– 38 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Heating and Air Conditioning

aware of a refrigerant leak on your vehic le, have y our system serviced immediately and observe the following precautions:

– Stay away from the hot engine until the exhaust

manifold has cooled.

– Do not permit any open flame in the area. Even a

match or a cigarette lighter may generate a hazardous quantity of poisonous gas.

– Do not smoke in the area. Inhaling gaseous

refrigerant through a cigarette may cause violent illness.

WARNING! Ne ver idle y our vehicle for prolonged periods of time if you sense that exhaust fumes are entering the cab. Investigate the cause of the fumes and correct it as soon as possible. If the vehicle must be driven under these conditions, drive only with the windows slightly open. Failure to repair the source of the exhaust fumes may lead to personal harm.

NOTE: Keep the engine exhaust system and the vehicle’s cab ventilation system properly maintained. It is recommended that the vehicle’s exhaust system and cab be inspected:

• By a competent technician every 15,000 miles.

• Whenever a change is noticed in the sound of the exhaust system.

• Whenever the exhaust system, underbody, cab or sleeper is damaged.

NOTE: To allow for proper operations of the vehicle ventilation system, keep the inlet grille at the base of the windshield clear of snow, ice, leaves, and other obstructions at all times.

WARNING! Do not stay in the vehicle with the engine running or idling for more than 10 minutes with the vehicle’s Heater and A/C ventilation system in RECIRC or at LOW FAN SPEED. Even with the ventilation system ON, running the engine while parked or stopped for prolonged periods of time is not recommended.

Controls

The heater and air conditioning control unit is mounted in the center dash console, below the radio. The standard control unit has four controls to regulate air flow and temperature in

Medium Duty

(R10/06) Y53-6008 – 39 –

Heating and Air Conditioning Operating Instructions

the cab: fan speed switch (A), air directional control switch (B), air temperature switch (C), and air circulating mode switch (D). With optional air conditioning, a fifth switch (E) is used.

Fan Speed Control

The fan speed rotary switch (A) allows you to select one of four blower speeds (1-4).

Air Direction Control

The air direction rotary switch (B) controls the air movement within the cab. Fiv e modes direct the air flo w to the three sets of air outlets: front panel, floor, and window defrost:

1.Front Panel only

2.Panel and Floor (Bi-level)

3.Floor only

4.Defrost and Floor (Bi-level)

5.Defrost only

Temperature Control

The temperature rotary switch (C) allows you to adjust and maintain a comfortable internal cab temperature.

Air Circulation Control

The air circulation rocker switch (D) allows you to select FRESH air from outside the cab or recirculate (RECIRC) air from within the cab.

Air Conditioner Control

The optional air conditioner is engaged with this rocker switch (E).

Heating

To heat the cab: select the desired air direction and circulat ing mode (B and D) and set the temperature knob (C) to hot (red position on the control). Adjust the fan speed (A) as desired.

– 40 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Heating and Air Conditioning

CAUTION: During extreme cold weather, do not blow hot air onto cold windshields. This could crack the glass. Turn the air direction lever to Defrost and adjust the fan speed accordingly while the engine warms. If the engine is already warm, move the temperature selector to Cool, then gradually increase the temperature when you see that the windshield is starting to warm up.

Defogging

NOTE: The air conditioning system is active when the Defrost mode is selected.

To defog the windshield: select air direction mode 4 or 5 and turn the fan speed switch (A) to high. Set the temperature knob (C) to hot (red position on the control). The air conditioner (if equipped) is automatically activated to remov e moisture from the cab. After the windshield is clear, adjust the controls as desired.

HEAT ING A/C CONTROL

CONTROLS

Fan Speed (A) High (4) Adjust High (4) Adjust High (4) Adjust Air Direction

Mode (B) Panel

Temperature (C) Warm Adjust Cool Adjust Warm Adjust Air Circulation

Mode (D) Air Conditioner -

AC (E)

HEATING COOLING DEFOGGING

MAX NML MAX NML MAX NML

Panel or BiLevel

(2)

Adjust Adjust

(1)

Recirc Fresh Record Fresh Recirc Fresh

OFF OFF ON ON — —

Defrost

(5)

Defrost

or Bi-

Level (4)

Cooling

To cool the cab: turn on the air cond itioner (if equipped) (switch E), set the temperature knob (C) to cool (blue side), and the fan (A) to high until the cab becomes cool—adjust as desired.

For Efficient Cooling:

1. Ensure all heater/air conditioner controls are off.

2. Start the engine. Allow time for warm–up.

Medium Duty

(R10/06) Y53-6008 – 41 –

Heating and Air Conditioning Operating Instructions

NOTE: A cold compressor can cause refrigerant to liquefy and warp the valve plates or cause a hydr aulic lock. Warm the engine before starting the air conditioner.

3. Set the air conditioner for maximum cooling.

4. Close all windows.

5. Idle the engine between 1000 and 1500 rpm and turn the fan switch to High.

6. After the cab temperature cools to a comfortable level, adjust the fan speed and other controls to keep the desired condition.

If the air conditioner does not cool the air, have the unit checked at an Authorized Service Center.

NOTE: When the air conditioner isn't in regular use, operate it for at least 15 minutes at least once a month or every 5,000 miles (8,000 km), whichever comes first. This will lubricate the seals in the air conditioning system.

– 42 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Accessories

ACCESSORIES

Radio

As an option, your vehicle has either an AM/FM Stereo Receiver or an AM/FM Stereo/Cassette Player.

For instructions on how to operate your particular radio, see the manufacturer's Radio Operating Instructions in the glove compartment.

Cigarette Lighter

NOTE: The cigarette lighter will operate with the ignition key in either the OFF, ACC (accessory), or IGN/ACC position.

To operate, push in on the knob end of the lighter. After a f e w moments, the lighter will automatically pop out, glowing hot and ready to use. After use, insert the lighter back into the socket without pushing all the way in.

The socket of the cigarette lighter may be used to operate 12 volt, 15 ampere appliances, such as a hand spotlight or small vacuum cleaner.

WARNING! Do not exceed the voltage/amperage capacity of the cigarette lighter. It could re sult i n a fire. Follow all warnings and instructions in the operator's manual for the appliance you are using.

Ashtray

To open, pull on the upper side of the panel. To close, push against the panel.

WARNING! Do not place paper or other combustible substances in an ashtray. It could cause a fire. Keep all burnable materials besides smoking materials, out of the ashtray.

Air Operated Horn (Option)

Your Medium Duty may be equipped with an air horn. To operate, pull on the lanyard extending from the overhead header panel. Your vehicle also has an electric horn. See page 56

Medium Duty

(R10/06) Y53-6008 – 43 –

Accessories Operating Instructions

Glove Compartment

A glove compartment is provided to store important docu ments, the vehicle literature set (including this Operator's Manual) and other related materials. You can open it by pushing the knob on the front.

• To close, push the cover up and press to latch it.

• You can lock and unlock the glove compartment door with your ignition key; turn it clockwise to lock and counterclockwise to unlock.

WARNING! Do not drive with the glove compartment open, it can be dangerous. In an accident or sudden stop, you or a passenger could be thrown against the cover and be injured. To reduce the risk of personal injury during an accident or sudden stop, keep the glove compartment closed when the vehicle is in motion.

WARNING! Do not carry loose objects in your cab, it can be dangerous. In a sudden stop, or even going over a bump in the road, they could fly through the air and strike y ou or a passenger. You could be injured or even killed. Secure all loose objects in the cab before moving the vehicle.

Dome Light

The dome light is automatically activated when you open the door. To turn the dome light on when you are inside the cab, turn the headlight switch counter–clockwise until it clicks and the light comes on.

– 44 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Seats

SEATS

Introduction

This section covers the operation and safe use of your Medium Duty seats. For further information on features and adjustment of the seat, see the manufacturer's literature included with the vehicle.

Seat Adjustment

WARNING! Do not adjust the driver's seat while the vehicle is moving. A sudden or unexpected seat movement can cause the driver to lose control of the vehicle. Make all adjustments to the seat while the vehicle is stopped.

• After adjusting the seat and before driving off, always check to be sure that the seat is firmly latched in position.

Standard Driver's Seat

The standard driver's seat can be adjusted forward and rearward. These movements are each controlled by levers located on the FRONT of the seat.

Driver's Seat with Air Suspension (Option)

WARNING! Before driving or riding in the vehicle, be sure that there is adequate head clearance at maximum upward travel of seat. Serious injury may occur if head clearance is not adequate.

CHUGGER-SNUBBER

LOCK-OUT FEATURE

Move handle down to

unlock

FRONT CUSHION

HEIGHT

Lift and pull forward

to raise position

FORE & AFT ISOLATOR

Move to left and slide

seat to desired position

BACKREST TILT

Rotate knob for

infinite selection of

SEAT RIDE HEIGHT

LUMBAR ADJUSTMENT

Push switch up to inflate

Push down to deflate

Peterbilt Ultraride II Highback Air Seat

settings

03017

Medium Duty

(R10/06) Y53-6008 – 45 –

Seats Operating Instructions

Safety Restraint Belts

The right and left seats are equipped with 3-point lap/shoulder belts; the center seat has a 2-point seat belt. Safety belts have proven to be the single most effective means available for reducing the potential for either serious injury or death in motor vehicle accidents. Therefore, read and follow these instructions and always observe user warnings pertaining to safety belts.

0917A

Unbelted Person in Crash

WARNING! Do not drive vehicle without your seat belt and your riders’ belts fastened. Riding without a safety belt which is properly fastened can lead to increased injury or death in an accident. Unbelted riders could be thrown into the windshield or other parts of the cab or could be thrown out of the cab. They could strike another person. Injuries can be much worse when riders are unbelted. Always fasten your seat belt and be sure anyone riding with you does the same.

Lap/Shoulder Belt

The combination lap-shoulder belt is equipped with a locking mechanism. The system adjusts automatically to a person's size and movements as long as the pull on the belt is slow.

Hard braking or a collision locks the belt. The belt will also lock when driving up or down a steep hill or in a sharp curve.

To fasten the belt:

1. Grasp the belt tongue.

2. Pull the belt in a continuous slow motion across your chest and lap.

– 46 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Seats

• Belts should fit snugly across the pelvis and chest. Make sure any slack is wound up on the retractor.

To unfasten the belt:

Push in the release button on the buckle. The belt will spring out of the buckle.

• To release a locked belt, lean back to take the body pressure off of the belt.

• To store a lap-shoulder belt, allow the belt to wind up on the retractor by guiding the belt tongue until the belt comes to a stop.

01888

Proper Safety Belt Adjustment

3. Insert the belt tongue into the buckle on the inboard side of the seat.

4. Push down until the tongue locks securely (with an audible click). Pull on the belt to check for proper fastening.

• Pull the shoulder section to make sure the belt fits snugly across the chest.

• The shoulder belt must be positioned over the shoulder—it must never rest against the neck.

Medium Duty

(R10/06) Y53-6008 – 47 –

Your combination lap-shoulder belt may need adjustment. Adjust safety belts properly.

• The lap belt should be worn as low and tight on the hips as possible. Make sure any slack is taken up by the belt mechanism.

• The shoulder belt should fit snugly across your body. It should be positioned midway over the shoulder (nearer to the door); it should never rest against your neck.

Seats Operating Instructions

Lap Belt Shoulder Belt

Too High on Hips

Correct

Safety Restraint Belts

Incorrect

Correct (over arm)

• Be sure, also, that your belt is not too loose. A loose belt could allow you to slide under it in an accident, and that could bring the belt up around your abdomen.

• Do not twist the belt in the process of putting it on. A twisted belt will not work as well to protect you.

WARNING! Always wear your seat belt low over your pelvic bones.

– 48 – Y53-6008

Incorrect (under arm)

Incorrect (twisted)

• You can be seriously injured if your belt is buckled too high. In a crash, it would apply force to your abdomen, not your pelvic bones. This can result in serious internal injuries.

• Do not drive with your seat belt loose. A seat belt that is too loose can allow you to fall too far forward, possibly causing head and neck injuries. You could strike the wheel or the windshield. Adjust your belt so that there is no more than 1 in. (25mm) of slack.

Medium Duty (R10/06)

Operating Instructions Seats

WARNING! Do not wear the shoulder belt under your arm or otherwise out of position. In a crash your body would move too far forward, increasing the chance of head and neck injury. Also, the belt would apply too much force to the ribs, which are not as strong as your shoulder bones, and could cause you to suffer internal injuries. Wear the shoulder belt over your shoulder (see

Safety Restraint Belts” on page 46).

“ WARNING! Do not twist the belt in the process of

putting it on. A twisted belt will not work as well to protect you. In a crash, the full width of the belt would not be protecting you. A twisted belt could cut into your body and cause serious injuries. Straighten the belt before buckling it. If you are unable to wear it without twisting it, have your dealer or service person repair it as soon as possible.

Safety Restraint Tips

NOTE: Per FMCSR 392.60 - Unauthorized Persons Not to be Transpor ted. Federal law prohibits the transportation of persons in commercial vehicles unless they are specifically authorized in writing by the motor carrier. See the cited FMCSR for a complete description of the regulation and exemptions.

• Any authorized person riding in your vehicle should wea r a seat belt. A responsible operator sees to it that everyone in the vehicle rides safely—and that means with a seat belt.

• Do not strap in more than one person with each belt.

• Do not wear a belt over rigid or breakab le objects in or on your clothing, such as eye glasses, pens, keys, etc., as these may cause injury in an accident.

• Several layers of heavy clothing may interfere with proper positioning of belts and reduce the overall effectiveness of the system.

• Keep belt buckles free of any obstruction that may prevent secure locking.

• Damaged or worn belts, subjected to excessive stretch forces from crashes, cuts or tears, or normal wear, must be replaced—they may not protect you if you have an accident.

• If belts show damage to any part of assembly, such as webbing, bindings, buckles or retractors, they must be replaced.

• Do not allow safety belts to become damaged by getting caught in door or seat hardware, or rubbing against sharp objects.

Medium Duty

(R10/06) Y53-6008 – 49 –

Seats Operating Instructions

• The belts must be kept clean or the retractors may not work properly.

• Never bleach or dye seat belts: chemicals can weaken them. Do, however, keep them clean by following the care label on the belts. Let them dry completely before allowing them to retract.

• Make sure the belt of the unoccupied passenger seat is fully wound up on its retractor, so that the belt tongue is in its stowed position. This reduces the possibility of the tongue becoming a striking object in case of a sudden stop.

• Do not modify or disassemble the seat belts in your vehicle. They will not be avail able to keep you and your passengers safe.

• If any seat belt is not working properly, see an Authorized Service Center for repair or replacement.

WARNING! Before driving or riding in a vehicle, ensure that there is adequate head clearance at maximum upward travel of seat. Shorten the tether belt as necessary to provide adequate head clearance. Serious injury may occur if head clearance is not adequate.

Tether Belts

Tether belts are installed on suspension seats. They help secure the seat to the floor to restrain it in case of a sudden stop or an accident.

Fixed Tethers

If your Medium Duty has been equipped with fixed length tethers, no manual adjustment is required. The same inspection and replacement guidelines should be used as stated on page 197

WARNING! Do not remove, modify, or replace the tether belt system with a different tether system. A failed or missing tether belt could allow the seat base to fully extend in the event of an accident leading to greater injuries or death.

WARNING! F ailure to adjust tether belts pr operl y can cause excessive movement of the seat in an accident. This could lead to greater injuries to you. T ether belts should be adjusted so that they are taut when the seat is in its most upward and forward position.

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Medium Duty (R10/06)

Operating Instructions Seats

Tether Adjustment

• Make sure that the tether belt is attached to the cab floor and seat frame. It should be routed through the buckle on each side.

• Often the attachments are made using a split-type hook. Make sure both halves of the hook are around the anchor bracket.

• To lengthen the tether, turn the buckle to a right angle to the webbing. Then pull the buckle. To shorten the tether, pull on the strap.

Komfort–Lok® Latch

Your Peterbilt contains a feature designed to eliminate cinching and provide improved safety and comfort. Cinching is the condition where a belt becomes continually tighter around you during a rough, bouncy ride. The need for this feature increases with rough road conditions, par tic ularly over long distances. To eliminate cinching, simply activate the Komfort–Lok®

1. Fasten the seatbelt according to the directions in the pre -

2. You are now ready to activate the Komf ort–Lok. Lean for-

3. When the slack is right, flip the latch cover up, cinching it

4. To release the Komfort–Lok latch, reach up and pull the

5. When you want to get out of the cab, release the latch,

feature at the appropriate time:

vious “Safety Belt Restraint” section.

ward to pull a little slack in the belt (maximum of one inch, measured from the belt to your chest). Be sure to allow only a small amount of slack.

into place.

latch cover open (down), or simply pull down on the shoulder belt.

then just push the button on the buckle.

Medium Duty

(R10/06) Y53-6008 – 51 –

Seats Operating Instructions

During Pregnancy

LATCH COVER

The Komfort–Lok latch

LATCH COVER

DOWN

02395

Pregnant women should always wear combination lap/shoulder belts. The lap belt portion must be wor n snugly and as low as possible across the pelvis. To avoid pressure on the abdomen, the belt must never pass over the waist. Sometimes pregnant women worry that in a crash the seat belt could hurt the baby . But if a woman wears her belt properly— low over her pelvis, below her abdomen—the belt will not harm the baby, even in a crash. And remember—the best way to keep an unborn baby safe is to keep the mother safe.

Passengers

Anyone riding in your vehicle should wear a seat belt. A responsible operator sees to it that ever yone in the vehicle rides safely—and that means with a seat belt.

Belt Damage and Repair

Damaged belts in the cab must be replaced. Belts that have been stretched, cut, or wor n out may not protect you in an accident.

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Medium Duty (R10/06)

Operating Instructions Seats

If any seat belt is not working properly, see an Authorized Service Center for repair or replacement.

For further information on seat belts and seat belt maintenance, see “

Safety Restraint System — Inspection,” P ag e

197.

Pregnant Woman with Belt Properly Worn

Medium Duty

(R10/06) Y53-6008 – 53 –

Steering Column and Mirrors Operating Instructions

STEERING COLUMN AND MIRRORS

Introduction

This section covers the standard steering column controls and mirror operation. Depending on how your Medium Duty is configured, some or all of these features are installed on your vehicle.

Turn Signal/High Beam Switch

NOTE: The ignition key must be turned to IGN & ACC for the signal/switch to operate.

The lever-action turn signal/high beam switch is located on the left side of the steering column.

Turn Signals

• To signal a right turn, push the lever up (clockwise).

• To signal a left turn, push the lever down (counterclockwise).

TRAILER

BRAKE VALVE

TURN

SIGNAL/HIGH

BEAM SWITCH

EMERGENCY FLASHER

Steering Column Controls

02596

High Beam

NOTE: The headlights must be “ON” for the high beam switch to operate.

• To switch your headlights to lower or higher beam, push and release the button on the end of the turn signal stalk. The blue indicator light in the instrument panel will be ON when the high beam is being used.

• To return to previous beam: push and release the button again.

– 54 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Steering Column and Mirrors

Emergency Flasher Switch

The four-way Emergency Flasher switch is on the turn signal body, just below the turn signal lever. The emergency flasher makes all four turn signals (front and rear) flash simultaneously. The flasher works independently of the ignition switch. You should alwa ys use the flasher if the v ehicle is disabled or parked under emergency conditions.

• To operate the emergency flasher, pull the lever out.

• The flasher is self-cancelling. To turn it off, activate the left or right turn signal.

WARNING! Use your Hazard Flasher Warning System any time you ha ve to stop off the road or on the side of the road, day or night. A hard-tosee vehicle can result in an injury accident. Another vehicle could run into you if you do not set your flashers. Always move the vehicle a safe distance off the road when stalled or stopped for repairs.

•Your disabled vehicle can be dangerous for you and others. The hot exhaust system could ignite dry grass, brush, spilled fuel, or other material that can cause fires. Do not park or operate your vehicle in areas where the hot exhaust system could cause a fire.

Trailer Brake Hand Valve

This hand valve, mounted on the steering wheel column of tractor/trailer vehicles, provides air pressure to apply the trailer brakes only. It operates independently of the foot treadle valve. See page 83 the Trailer Brake Hand Valve.

for more instructions on proper use of

Medium Duty

(R10/06) Y53-6008 – 55 –

Steering Column and Mirrors Operating Instructions

Adjustable Steering Column (option)

Some vehicles are equipped with an optional tilt-telescoping steering column. The tilt feature allows forward and rearward movement of the wheel. The telescoping feature allows you to move the wheel up and down.

WARNING! Do not adjust the Tilt-Telescoping Steering Wheel while the vehicle is in motion, it could cause loss of control. You would not be able to steer properly and could have an accident. Make all adjustments to the steering column while the vehicle is stopped.

The Tilt-Telescoping Lever is located on the left side of the steering column.

To tilt the wheel:

• PULL the lever up, toward yourself. Move the steering wheel to the desired angle, then release the lever to lock the wheel in the correct position.

To raise or lower the wheel:

• Push or pull the steering wheel to the desired height, then release the lever to lock the wheel at that position.

Horn

To sound the electric hor n, press the button in the center of the steering wheel.

Mirrors

Your vehicle comes equipped with two outside rear view mirrors that enable you to see to the sides and behind y our vehicle. Be sure both mirrors are adjusted properly before you begin driving.

• To provide good visibility, adjust each mirror so the side of your vehicle appears in the inboard part of the mirror.

WARNING! Convex mirrors can distort images and make objects appear smaller and farther away than they really are. You could have an accident if you are too close to another vehicle or other object. Keep plenty of space between your vehicle and others when you turn or change lanes. Remember that other objects are closer than they may appear.

– 56 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Steering Column and Mirrors

Power Mirror (Option)

Your Medium Duty may have motoriz ed side mirrors. A s witch for each, located on the dash, controls the adjustment.

To adjust the mirror:

• Push the arrow that points toward the direction you want to move the mirror.

NOTE: The power mirror s witch does not control the adjustment of the convex mirrors.

Heated Mirrors (Option)

Your vehicle also may hav e heated mirrors . To defrost mirrors in cold weather, turn the mirror heat switch to ON.

You can keep the mirror heat on to ensure t hat the mirrors stay free of ice or condensation. They automatically adjust to the temperature outside, providing the right amount of heat to keep them clear.

Medium Duty

(R10/06) Y53-6008 – 57 –

Operating the Engine Operating Instructions

OPERATING THE ENGINE

Introduction

For detailed information on starting and operating the engine, refer to the Engine Operation and Maintenance Manual provided with your Medium Duty.

Because each vehicle is custom-equipped, all engine operation instructions presented in this section are general. You will want to consult the engine manual to find out details about your vehicle's specific engine requirements. You may need to use a slightly different procedure from the one outlined here.

Also, read the American Tr ucking Association's (ATA) Truck Driver's Handbook. It will give you tips on starting, shifting, and driving your vehicle.

WARNING! Do not use ethe r or other starting fluids as a cold-starting aid in your Medium Duty. Your engine uses e ither an el ectrical gr id or an open flame inside the manifold, to heat the air/ fuel mixture for cold weather starting. If ether or another starting fluid is used, the air/fuel will ignite inside the manifold, which could cause an explosion and severe injury.

WARNING! Do not start or let the engine run in an enclosed, unventilated area. Exhaust fumes from the engine contain carbon monoxide, a colorless and odorless gas. Carbon monoxide can be fatal if inhaled.

•Do not park or operate the vehicle in areas where the hot exhaust system may come in contact with dry grass, brush, spilled fuel or other material that can cause a fire.

CAUTION: The use of a winterfront can result in excessive engine coolant, oil, and charge air (intake) temperatures, which c an lead to overheating and possible engine damage. If you must use a winterfront

• Refer to the “Engine Operation and Maintenance Manual” for operating restrictions and recommendations.

• Use only a winterfront available from your Peterbilt dealer that is compatible with a 2002 EPA-com pliant engine cooling sy stem. These winterfronts are specifically designed for use with new grill snap patterns.

– 58 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Operating the Engine

Starting Procedure — Normal Temperature

Use the following procedure to start your Medium Duty when outside temperatures are at or ABOVE normal starting temperatures. Check the Engine Operation and Maintenance Manual for starting temperatures.

1. Set the parking brake.

NOTE: When any one of the following is true, oil should be applied to the turbocharger oil inlet port: (1) if the en gine has not been sta r ted for more than 25 days; or (2), the outside temperature is very cold; or (3), the oil filter has been changed.

•With an oil can, squirt approximately one-half cup (120 ml) of clean, specified engine oil into the turbocharger oil inlet port. This will keep the turbocharger bearings lubricated until the engine oil pressure gets up to normal.

2. Insert key into the ignition switch.

3. Disable (or turn OFF) the following systems prior to starting the engine: the exhaust brake, the dual-speed rear axle (put in LOW), and block heater (if equipped).

4. Disengage the transmission: place the shift lever in the Neutral position.

5. Disengage (depress) the clutch (with manual transmission).

6. Turn the ignition switch to the IGN & ACC position. For normal temperatures, no accelerator advance is necessary. See “Use of Accelerator” below. If the “WAIT TO START” indicator lamp turns ON, wait until the indicator lamp goes OFF (approximately 60 seconds) before attempting to start the engine. (For each engine and ambient temperatures, warm-up cycles will vary.)

7. Turn the ignition switch to the IGN & START position to engage the starter. Crank the engine until it starts. If the engine does not start within 30 seconds, release the key.

Use of Accelerator

• For mild to warm temperatures above 60°F (16°C) keep your foot OFF the accelerator pedal while cranking. If the engine does not start after 5 seconds, apply full throttle while cranking.

• For below normal starting temperatures fully depress the accelerator (throttle) pedal after engaging the starter.

NOTE: Pumping the accelerator will not assist in starting the engine.

Medium Duty

(R10/06) Y53-6008 – 59 –

Operating the Engine Operating Instructions

CAUTION: To help avoid overtaxing the starter motor or batteries, or causing engine damage, follow the recommendations listed below:

• Do not engage starter for more than 30 seconds at a time.

• Wait two minutes between each attempt to start the engine. This allows the starter motor to cool and time for the batteries to regain power.

• If the engine fails to start after a couple of tries, there could be a malfunction with the engine or other related system. Make any adjustments or repairs necessar y before trying to start the engine again.

When the engine starts:

• Watch the oil pressure gauge. Oil pressure should rise within 15 seconds after the engine starts. If the oil pressure does not rise, stop the engine. Find what is wrong before restarting. Check the Engine Operation and Main- tenance Manual for the right oil pressure for your vehicle's engine. In most engines, idle pressure should be about 15 psi.

CAUTION: Never operate the starter motor while the engine is running. The starter and flywheel gears could clash or jam, severely damaging them.

• Wait until normal engine oil pressure registers on the gauge before idling or accelerating the engine beyond 1000 rpm.

• Watch the air pressure gauge. Wait until both pointers register at least 100 psi (689 kPa) before releasing the spring brake and moving the vehicle. Also, check the alarm system for any type of faults and correct them before moving the vehicle.

CAUTION: Do not try to put the vehicle in motion before pressure in the air system reaches 100 psi (689 kPa) because the wheels will still be locked by the spring brake action.

•Unnecessary stress and possible brake malfunction could occur if the vehicle is forced to move before the air system reaches 100 psi (689 kPa).

– 60 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Operating the Engine

Starting Procedure — Cold Weather

In addition to the previous “Normal Starting Procedures, ” use these Cold Weather Starting guidelines when the air temperature falls below a certain temperature. Check your Engine Operation and Maintenance Manual for further details on when cold weather starting aids are needed.

Using special cold-starti ng equipment will help the eng ine start easier. And in cold weather, fast engine starting helps relieve the loads on the electrical system and cranking motor. If you follow these few simple guidelines, you will extend the service life of your vehicle's engine:

• Keep the electrical system in top condition.

• Use the best quality and recommended grade of fuel (see Engine Operation and Maintenance Manual).

• Use the recommended engine lubricating oil.

• As stated in the Normal Starting Procedures, when temperatures are below normal, fully depress th e accelerator pedal after engaging the starter.

Engine Block Heater (Option)

To preheat the engine before starting, plug the optional engine block heater into a properly grounded AC electrical source. Do not start the engine with the heater plugged in.

WARNING! Engine block heaters can cause fires resulting in serious personal injury and/or property damage if not properly maintained and operated. Regularly inspect the engine block heater wiring and connector for damaged or frayed wires. Do not use the heater if there are any signs of problems. Contact your Authorized Service Center or the manufacturer of the heater if you are in need of repairs or information.

CAUTION: Always unplug the heater before starting the engine. Damage to the cooling system could occur if the heater is not turned OFF (unplugged).

When the temperature falls below 0°F (–18°F) for Cater pillar engines, or –10°F (–24°C) for Cummins engines, the block heater is required.

Medium Duty

(R10/06) Y53-6008 – 61 –

Operating the Engine Operating Instructions

• Use a solution of half ethylene glycol antifreeze and half water for best heater performance. Do not exceed 60 percent concentration of antifreeze, as it can shorten heater life. See page 146

• After servicing the cooling system, operate the vehicle for a day or two befo re using the heater. Trapped air inside the engine needs time to escape.

for more information.

Cold Weather Starting—Air Intake Heater

Do not use ether or any other starting fluid as a cold starting aid in your Medium Duty. Engine conditions are automatically monitored and in cold weather the fuel/air mixture is preheated in the manifold.

With each engine make, the air intake heating system works differently. T o understand fully ho w your engine's heating system operates, see the engine Operation and Maintenance Manual for details.

On most systems the engine block temperature is monitored at startup; other systems monitor the engine oil pressure, coolant temperature, and time, as well. When the pre-set conditions are met, the heater automatically engages.

Air Intake Heater

The air intake heater system will alert you when the engine requires preheat. On the dash is a “WAIT TO START” warning light (See page 20 starting the engine.

Turn the key to IGN & ACC: the WAIT TO START light will light up for bulb check.

Wait until the WAIT TO START light goes off before you start the engine.

When the WAIT T O START light goes off , the preheat cycle is complete and you can start the engine normally.

). This light alerts you to wait before

– 62 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Operating the Engine

After the engine starts and until operating conditions reach a certain point, the system will continue to operate to eliminate white-smoke exhaust.

Engine Warm–Up and Idling

The purpose of engine warm-up is to allow an oil film to be established between pistons, shafts, and bearings while your engine gradually reaches operating temperature.

Warm–Up Procedure

1. After you have started the engine, idle the engine at approximately 600 rpm while you check vital engine systems:

– oil pressure – air pressure – alternator output (with the optional voltmeter)

2. Before placing engine under a load, continue warm-up with the engine at 900 to 1000 rpm for 3 to 5 minutes.

• When a cold engine is started, increase the engine speed (rpm) slowly to be sure adequate lubr ication is available to the bearings and to allow the oil pressure to stabilize. In extremely cold temperatures, you may have to increase idle speed.

NOTE: In colder climates where the temperatures are often below freezing, sufficient warmup for turbocharged engines is especially important. Chilled external oil lines leading to the turbocharger will slow the oil flow until the oil warms, reducing oil available for the bear ings. Watch the engine oil pressure gauge for a warming trend before increasing engine idle speed (rpm).

3. Continue the engine warm-up until the coolant temperature reaches at least 130°F (54°C). At this temperature, you can use partial throttle. Wait until the coolant temperature is at least 160°F (71°C) before operating at full throttle. See “

67.

WARNING! Exhaust fumes from the engine contain carbon monoxide, a colorless and odorless gas. A poorly maintained, damaged, or corroded exhaust system can allow carbon monoxide to enter the cab or sleeper. Failure to properly maintain your vehicle could cause carbon monoxide to enter the cab and cause serious illnesses.

Operating Manual Transmissions” on page

Medium Duty

(R10/06) Y53-6008 – 63 –

Operating the Engine Operating Instructions

Idling the Engine

Under most circumstances, continuous idling of your engine merely wastes fuel. In sev ere Arctic w eather conditions , ho wever, you may need longer idling to be sure all parts of your engine are fully lubricated.

CAUTION: Do not allow your engine to idle, at low rpm (400–600 rpm), longer than five minutes. Long periods of idling after the engine has reached operating temperatures can decrease engine temperature and cause gummed piston rings, clogged injectors, and possible engine

damage from lack of lubrication. The normal torsional vibrations generated can also cause transmission wear.

• During the time it takes you to drink a cup of coffee, your engine can cool as much as 60° F (33° C) below normal operating temperature. To keep the engine warm during a short break, turn it off. Do not allow your engine to idle longer than five minutes.

Engine Fan Switch (Option)

Your Medium Duty may have an engine fan switch installed as an option. The switch, which is mounted on the accessory switch panel, allows you to control the engine f an manually or automatically.

• With the ignition key switch ON and the fan switch in the ON position, the engine fan will be on regardless of engine temperature.

• With the engine fan switch in the AUTOMATIC position, the engine fan will automatically turn on when the engine coolant reaches a temperature of about 200°F (93°C)

– 64 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Operating the Engine

WARNING! Do not work on or near the fan with the engine running. Anyone near the engine fan when it turns on could be seriously injured. If it is set at MANUAL, the fan will turn on any time the ignition key switch is turned to the ON position. In AUTO, it could engage suddenly without warning. Before turning on the ignition or switching from AUTO to MANUAL, be sure no workers are near the fan.

CAUTION: The fan or equipment near it could be damaged if the fan turns on suddenly when you do not expect it. Keep all tools and equipment away from the fan.

NOTE: Do not operate the engine fan in the MANUAL position for extended periods of time. The fan hub was designed for intermittent operation. Sustained operation will shorten the fan hub's service life as well as reduce fuel economy.

Cruise Control (Option)

This feature improves fuel mileage and reduces driver fatigue by maintaining a constant vehicle speed. The cruise control will only operate above a programmed minimum vehicle speed, 15 mph for the CAT 3126B engine, 30 mph for the Cummins ISC engine.

Engaging the Cruise Control

02901

NOTE: Ensure that the vehicle speed is above the minimum cruise control speed and the engine speed is above 1100 rpm.

1. Move the ON/OFF switch to the ON position.

NOTE: Toggling the SET/RESUME switch to the RESUME position at this point will select the previously set cruise speed.

2. Accelerate the vehicle to the desired cruise speed.

Medium Duty

(R10/06) Y53-6008 – 65 –

Operating the Engine Operating Instructions

3. Toggle the SET/RESUME switch lever to the SET position to set the cruise speed. This toggle switch has additional functions that are set by the manufacturer. The two functions are:

•To decrease the cruise set speed, hold the SET/RESUME switch in the RESUME position and coast to a lower speed.

02901b

•To increase the cruise set speed, hold the SET/RESUME switch in the SET position; this will accelerate the vehicle to a higher speed.

02901a

Disengaging the Cruise Control

Do one of these steps to disengage the cruise control:

• Move the ON/OFF switch to the OFF position.

02901off

• Depress the brake pedal. or

• Depress the clutch pedal.

Reengaging the Cruise Control

1. Move the ON/OFF switch to the ON position.

2. Toggle the SET/RESUME lever to the RESUME position.

– 66 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Operating the Transmission

OPERATING THE TRANSMISSION

Introduction

Your Medium Duty is equipped with either a manual or automatic transmission with special features and gearing to meet your particular needs. It is impor tant for you, the driver, to understand how your particular trans mission is operated. To do this, you have two sources of information: this Operator's

Manual and the transmission manufacturer's Driver/Operator's Instruction Manual. Because of the variety of different

transmissions installed in Medium Duty vehicles, operating procedures for your particular transmission are not included in this manual; therefore, you should read and understand both manuals. Read the general guidelines and instructions that follow and read the specific instructions contained in the transmission manufacturer's manual that is included with your vehicle.

NOTE: You will find a shift pattern diagram in the cab. Check to be sure you know the correct sequence for your particular transmission.

Operating Manual Transmissions

If your truck has an automatic transmission, go to page 71.

6, 9, 10, and 11–Speed Manual

The 6–speed synchronized manual transmission has 6 forward speeds and 1 rev erse . The 9–speed transmission has 9 forward and 2 reverse speeds, consisting of a 5–speed low range section and a 4–speed high range section.

For specific instructions on operating one of the optional 10or 11-speed transmissions, consult the t ransmission manufacturer’s Driver/Operator Instruction Manual.

Transmission Warm–Up

In cold weather [below 32°F (0°C)], you may find shifting sluggish when you first star t up. Transm ission warm-up is especially important at this time, but it is always a good idea to warm your transmission oil before starting out on the road.

To warm the transmission lubricating oil during engine warmup:

Medium Duty

(R10/06) Y53-6008 – 67 –

Operating the Transmission Operating Instructions

1. Put the transmission in Neutral.

2. Release the clutch pedal and let the transmission operate in Neutral for three to five minutes prior to shifting into either a forward or reverse range.

Putting the Vehicle in Motion

After making sure the vehicle's oil and air pressure are correct and all other par ts and systems are in proper work ing condition:

1. If your truck is equipped with a hand throttle, disengage the hand throttle before driving the vehicle.

2. Fully depress the clutch pedal until the clutch brake makes contact (see page 69 about 1 inch or less from the floorboard.

• The total stroke of the clutch pedal is about 10 inches. The first 1½ inches is free travel. After the free travel comes the release stroke, which is the part that fully releases the clutch. The last inch engages the clutch brake.

• Always start out in a low gear. Starting in a higher gear, even with a light load, will cause a very jumpy start and excessive wear.

). The contact will occur at

CAUTION: Always use first gear or a low speed range to start the vehicle in motion. The use of a higher gear or speed range forces undue strain on the engine, clutch, other transmission components, and may cause damage.

3. Evaluate the road surface conditions and terrain your vehicle is on. Select a gear low enough to let your v ehicle start forward with the throttle at idle.

4. Push the parking brake valv e handle (Yellow) against the dash panel to release the brakes.

5. Release the clutch pedal, then gradually accelerate to permit smooth starting,

6. Do not allow your v ehicle to roll (e v en a little) in the opposite direction during clutch engagement. If you need to start up on an incline, apply your service brakes before you release the parking brake. Then release y our service brakes as you engage the clutch and apply throttle.

For further instructions on operating your transmission, see the transmission manufacturer's manual that is included with your vehicle.

– 68 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Operating the Transmission

If you have a misaligned gear condition in your vehicle's transmission and cannot star t, gradually release the clutch, allowing the drive gear teeth to line up properly. Then the drive gear can roll enough to allow the teeth to line up properly and complete the shift.

The best engine performance and maximum economy is obtained if gears are properly selec ted. This efficiency is achieved by always selecting gears within optimum engine rpm, which is where maximum torque and power are obtained. For further information, see “ Techniques” on page 98.

More Driving Tips and

Shifting Gears in a New Vehicle

Shift carefully in a new vehicle. The tran smission may be a little stiff at first. Avoid gear clashing by closely following these procedures.

When you are operating a new vehicle or one that has been exposed to cold weather, you want the transmission lubricant (fluid) to circulate and coat the contacting surfaces of the gears. Metal contacting metal in moving parts may seriously damage your transmission—do not drive in one gear for long periods of time until the transmission lubricant has a chance

to coat all contacting surfaces. Carefully observe the free travel in the clutch for the first few hundred miles. As the clutch lining wears and high spots get worn smooth, you will get less free travel.

Clutch Brake and Travel (9–, 10–, and 11–Speed Transmissions only)

These transmissions utilize a clutch brake, rather than synchronizers. The clutch brake works by stopping all of the gears in the transmission, allowing you to easily shift into first gear or reverse without g rinding gears. The total strok e of the clutch pedal is about 10 inches. The first part is the release stroke: the part that fully releases the clutch. The last inch engages the clutch brake.

During hard-shifting with vehicle not moving

• To apply the clutch brake (while the vehicle is stopped) fully depress the clutch pedal to the floorboard to st op the gears. With the throttle at idle, select first gear then release the clutch pedal to let the vehicle start forward, until the clutch is fully engaged. See the transmission manufacturer's manual that is included with your vehicle for further details.

Medium Duty

(R10/06) Y53-6008 – 69 –

Operating the Transmission Operating Instructions

During Normal Driving

If you want to shift directly into any gear other than first or reverse, depress the clutch pedal only far enough to release the clutch. Pushing the clutch to the floor applies the clutch brake and could cause gear hang-up.

CAUTION: Be careful not to apply the clutch brake while the vehicle is moving. The purpose of the clutch brake is to stop the transmission so that you can shift into a starting gear without grinding gears. Applying the clutch brake when the vehicle is moving causes a braking effect on the drivetrain and shortens the service life of the clutch brake.

Double Clutching

Whether you are upshifting or down shifting, it is best to double clutch. Double clutching is easier on the tr ansmission and on the engine, helping your vehicle match engine speed with driveline speed and achieving clash-free shifts.

To double clutch:

1. Push the clutch pedal down to disengage the clutch.

2. Move the gear shift lever to Neutral.

3. Release the pedal to engage the clutch. This lets you control the rpm of the mainshaft gears, allowing you to match the rpm of the mainshaft gears to those of the output shaft.

• Upshifts: let the engine and gears slow down to the rpm required for the next gear.

• Downshifts: press accelerator, increase engine and gear speed to the rpm required in the lower gear.

4. Now quickly press the pedal to disengage the clutch and move the gear shift lever to the ne xt gear speed position.

5. Release the pedal to engage the clutch.

More Transmission Tips

“Riding” the Clutch

The clutch is not a footrest. Do not drive with y our f oot resting on the clutch pedal. It will allow your clutch to slip, causing excessive heat and wear—damage could result.

– 70 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Operating the Transmission

Release Bearing Wear

When you must idle your engine for any period of time, shift your transmission to Neutral and disengage the clutch (take your foot OFF of the pedal). This helps prevent unnecessary wear to your clutch release bearing, and it is less tiring for you, too.

Clutch Adjustment

Inspect manual clutches according to the manuf acturer's recommendations. Regular maintenance should be followed to maintain correct clutch adjustment. Have your dealer's Service Department perform any adjustment necessary.

Tips

• Always use the clutch when making upshifts or downshifts.

• Always select a starting gear that will provide sufficient gear reduction for the load and terrain.

• Never downshift when the vehicle is moving too fast.

• Never slam or jerk the shift lever to complete gear engagement.

• Never coast with the transmission in Neutral and the clutch disengaged.

• To provide smooth gear engagements while shifting, use proper coordination between shift lever and clutch.

Operating Automatic Transmissions

An automatic transmission makes shifting much easier, however it is important to understand how to operate the transmission efficiently. Please read the transmission manufacturer’s operation manual supplied with your vehicle.

There may not be a “park” position with your automatic transmission. Always be sure you apply the parking brake before leaving the cab.

WARNING!

without applying the parking brake. The truck could roll and cause an injury accident. Always apply the parking brake before you leave the cab.

Do not leave the cab of your vehicle

Medium Duty

(R10/06) Y53-6008 – 71 –

Using the Brake System Operating Instructions

USING THE BRAKE SYSTEM

NOTE: Today’s diesel engines have significant torque and startability power at low RPMs. Combinations of engine speed and available torque may overpower the vehicle’s parking brakes.

WARNING! Never drive your vehicle with the parking brakes applied. Always release t he parking brakes prior to moving the vehicle. Failure to disengage the parking brakes prior to moving your vehicle could result in excessive heat b uildup of the brakes and start a fire.

NOTE: If your truck is equipped with hydraulic brakes, go to page 88

Introduction

The operation of the vehicle's braking system and many v ehicle accessories depends upon the storage and application of a high-pressure air supply.

This air brake system is a multiple circuit type: it has a circuit for the front wheels, a separate circuit for the rear wheels, and one for the trailer (tractors only). The system is supplied by a compressor driven by the engine. The vehicle's compressor takes outside air and compresses it, usually to 100– 130 psi (690–896 kPa). This compressed air then goes to the reservoirs to be stored until needed.

When you operate your air brakes , the stored compressed air flows into the chambers where it is used to apply your truck and trailer brakes. That is why, when you push down on the brake pedal, you do not feel the same amount of pressure on the pedal that you do when you apply the brak es on your car. All you are doing on your truck is opening an air valv e to allow air to flow into the brake chambers.

WARNING! The brake system is a critical vehic le safety system. For the safety of you and others around you, have the vehicle submitted for periodic preventive maintenance checks as well as having any suspected problems immediately checked by an Authorized Service Center. Failure to properly maintain your brake system can lead to serious injury accidents.

– 72 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Using the Brake System

Brake Operation

WARNING! Do not drive through water deep enough to wet brake components, as it may cause the brakes to work less efficiently than normal. The vehicle's stopping distance may be longer than expected, and the vehicle may pull to the left or right when brakes are applied, which could contribute to an accident.

If you think your brak es hav e become w et, check th e rear and both sides of the vehicle for clear traffic , then gently apply the brakes, releasing and gently reapplying until the brakes dry out—restoring nor mal operation. Always check your brakes after driving through deep water to help reduce the possibility of personal injury or an accident.

Front Brake System

When the brake pedal is depressed, the front circuit portion of the treadle valve delivers air from the front service reservoir to the front axle brake chambers via a quick-release valve.

Simultaneously (on full truck configurations), air is also su pplied to the modulating valve control port. In the event of a rear service circuit failure, the modulating valve will exhaust air from the spring brake chambers, applying the spring brakes in proportion to the front circuit application.

Rear Brake System

When the brake pedal is depressed, the rear circuit portion of the treadle valve deliv ers air from the rear service reservoir to the service brake relay valve control port. The relay valve then delivers air directly from the rear service reservoir to the rear brake chambers in proportion to the treadle pressure.

On tractors without ABS, the relay valve is part of the BP-R1 brake valve, which automatically propor tions the dr ive axle brake application pressure when driving bobtail (without a trailer connected). The proportioning BP-R1 brake valve allows full use of the steer axle (front) brakes and reduces the chance that the drive axle brakes will lockup. The bobtail brake proportioning sy stem is automa tically tur ned off when a trailer is connected.

Medium Duty

(R10/06) Y53-6008 – 73 –

Using the Brake System Operating Instructions

Using the Parking Brake

The yellow diamond-shaped knob on the dash controls the truck/tractor parking brakes. These are spring brakes that you activate by releasing air pressure from their ch ambers. When they are not in use, air pressure compresses the springs and releases the brakes. Pulling the knob OUT applies the parking brake, which exhausts air from the chambers and allows the springs to extend and apply the brakes.

WARNING! Do not pull out the parking brake valve while the vehicle is moving. Stopping with the parking brake controls can cause a sudden wheel lock-up, loss of control, or over-take by following vehicles. You could be severely injured.

WARNING! Do not leave the cab without applying the parking brake. The truck could roll and cause an injury accident. Always apply the parking brake before you leave the cab.

Before you leave the cab:

1. Apply all parking brakes. Pull out the Yellow Parking Brake Control knob located on the dash. The Red (octagon-shaped) Trailer Air Supply Control knob on tractors will automatically pop out. (An optional dash warning light will indicate when the brake is ON.)

2. Shift the transmission into PARK position:

• manual transmission, select First or Reverse gear

• automatic transmission, select Neutral.

3. Turn the key to OFF.

4. Remove the key.

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Full Truck Parking Brake Control Knob

– 74 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Using the Brake System

(2) Trailer Air Supply Control (Red)

Combination (Tractor/Trailer) Parking Brake Control Valves

(1) Parking Brake Control (Yellow)

02394

The parking brakes act on the rear wheels only. They are spring-applied, with air pressure used to release them. Release air is supplied by both the front and rear circuit reservoirs through a double check valve.

To release the truck or tractor parking brakes ONLY:

• Push IN the Yellow knob on the dash. Your trailer will remain parked.

Below 60 psi (414 kPa) the Yellow par king brake valve remains OUT (ON position). If air pressure is not restored above 60 psi (414 kPa), the knob will automatically return to the OUT position if you attempt to push it in. See page 26

for more information.

To release the trailer brakes ONLY:

• Push IN the Red knob on the dash. The truck or tractor will remain parked.

To release the full combination of brakes:

•Push IN BOTH knobs on the dash.

• In the event that air pressure is reduced below a safe level: the low air warning light will come on first; if air pressure continues to drop, the parking brake valve will pop OUT, automatically applying the spring brakes.

CAUTION: Do not try to put the vehicle in motion before pressure in the system reaches 100 psi (689 kPa) because the wheels are locked by the spring brake action.

• Unnecessary stress and possible brake malfunction could occur if the vehicle is forced to move before the air system reaches 100 psi (689 kPa).

• Below 60 psi (414 kPa) the parking brake valve button remains in the applied (ON) position. If air pressure is not restored, the button will automatically return to its initial position.

Medium Duty

(R10/06) Y53-6008 – 75 –

Using the Brake System Operating Instructions

WARNING! If the air pressure falls below 60 psi (414 kPa) the spring brakes may stop the vehicle abruptly, which could result in an accident and/or injuries. Observe the red warning lamps on the gauges. If one comes on, do not continue to drive the vehicle until it has been properly repaired or serviced.

WARNING! Do not use the trailer hand brake or service brakes to park and hold an unattended vehicle—use the parking brakes. Because service brakes work with air pressure, these brakes could slowly release. Your vehicle could roll, causing a serious accident. Someone could be hurt or killed. Never rely on the service brakes to hold a parked vehicle.

Tractor and Trailer Air Supply Valve

Initial Charge

The red octagon knob contro ls the air supply t o the trailer. With the system completely discharged, both the Red (trailer air supply) and the Yellow (parking brake) knobs are OUT; thus, tractor and the trailer parking (s pring) brakes are applied.

To supply air to the trailer system and release the trailer parking brakes:

1. Allow the tractor air system pressure to build up to operating level.

2. When system pressure reaches 50 psi (345 kPa) the Red knob may be pushed IN.

3. Hold the Red knob IN by hand until the trailer air pressure builds to a pre-set level, about 45 psi. At this point it will remain in, charging the trailer system and releasing only the trailer brakes.

4. The Yellow knob will remain OUT (tractor brakes ON).

Normal Run Position

• The Yellow knob (system park) may now be pushed IN, which will supply air to the tractor spring brakes, releasing them.

• With both knobs pushed IN, air is now being supplied to both the trailer and the tractor spring brakes; all brakes are released.

– 76 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Using the Brake System

SYSTEM PARK OR CHARGE TRAILER

WITH TRACTOR PAR KED

TRAILER

AIR

SUPPLY

PARKING

BRAKE

NORMAL OPERATING

POSITION

TRAILER

AIR

SUPPLY

PARKING

BRAKE

PARK TRAILER WITH

TRACTOR RELEASED OR

BOBTAIL TRACTOR

TRAILER

AIR

SUPPLY

PARKING

BRAKE

YELLOWRED

YELLOW

RED YELLOW

RED

02393

Trailer Park or Emergency Brake Application Only

If you ev er have a failure or disconnect the air supply hose to the trailer, the trailer parking brakes will set. The Red knob will automatically pop OUT and seal off the tractor air reservoirs to protect the tractor air system pressure.

Medium Duty

To apply the trailer brakes only:

Pull OUT the Red knob. This will exhaust air from the trailer supply line, causing the tractor protection valve to close and the trailer spring brakes to apply. The trailer is now in “emergency” or “park.” This mode would be used to uncouple from the trailer and during bobtail operation (running without a trailer connected).

(R10/06) Y53-6008 – 77 –

Using the Brake System Operating Instructions

Parking Tractor and Trailer

• With both knobs pushed in for normal operating modes, the parking brakes of both the tractor and the trailer may be applied by pulling the Yellow knob OUT. This will exhaust the air from the tractor spring brakes , and sim ultaneously cause the Red knob to pop OUT, which will apply the trailer brakes. This complies with the FMVSS 121 requirement that one control should apply all the parking brakes on the vehicle.

Trailer Charge

• If both knobs are OUT (combination vehicle is parked), and it is desired to recharge the trailer, the Red knob may be pushed IN to repressurize the trailer supply line. The tractor will remain parked. For more information on air supply pressure requirements, see page 76

Brake Safety and Emergency

WARNING! Do not operate the vehicle in the event of a malfunction in any air circuit. The vehicle should not be operated until the system is repaired and both braking circuits, including all pneumatic and mechanical components, are working properly. Loss of system air can cause the service brakes to not function resulting in the sudden application of the spring brakes causing wheel lock-up, loss of control, or overtake by following vehicles. You could be in an accident and severely injured.

– 78 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Using the Brake System

Front Brakes — Truck

The following applies to full truck configurations:

If air pressure is lost in the front circuit, the vehicle front brakes will not operate. Check valves isolate the rear circuit, so the rear service brakes and parking brakes are unaffected. The spring brakes will not automatically ap ply as long as rear service pressure is maintained.

WARNING! If the remaining system pressure drops below 60 psi (414 kPa) due to repeated brake applications, the spring brakes will automatically apply—stopping the vehicle abruptly, potentially causing serious injury. Observe the warning light (BRAKE AIR) in the panel. If it comes on, do not continue to drive the vehicle until it has been properly repaired or serviced.

Rear Brakes — Truck

The following applies to full truck configurations:

If air is lost in the rear brake circuit, check valves isolate the front circuit, and front brake operation is unaff ected. Because this is a dual air system, spring brakes will not automatically apply as long as pressure is maintained in the front circuit.

When the brake pedal is depressed, the modulating valve detects the reduction or absence of rear service delivery pressure, and exhausts air from the spring chambers, applying the spring brakes in proportion to the front brake application.

When releasing the brake pedal, the modulating valve delivers front service air to th e sprin g brake chambers, releasing the spring brakes in proportion to the front brake application.

Thus, if there is a rear service failure, the remaining front axle braking is supplemented by modulated spring brake action on the rear axle.

WARNING! Efficiency of emergency braking depends on the amount of air available in the front circuit reservoir, wh ich is sufficient for a limited number of brake applications and releases.

• REMEMBER: when the remaining system pressure drops below 60 psi (414 kPa), the spring brake is automatically applied, stopping the vehicle abruptly, potentially causing serious injury . Observe the warning light (BRAKE AIR) in the panel, it will come on before the spring brakes are applied. If it comes on, do not continue to drive the vehicle until it has been properly repaired or serviced.

Medium Duty

(R10/06) Y53-6008 – 79 –

Using the Brake System Operating Instructions

Brakes — Tractor/Trailer

The following applies to tractor/trailer configurations:

If pressure is lost in the tractor front or rear circuit, the “check” valves isolate the unaffected circuit, allowing this circuit to continue normal operation. The trailer brakes are still functional.

• If air pressure is lost in the trailer supply/park circuit, and the pressure drops below 60 psi (414 kPa), the trailer spring brakes are automatically applied, and the tractor air pressure circuits are unaffected.

• If air pressure is lost in the trailer brake service circuit, and the pressure in the tractor front and rear circuits drops below 60 psi (414 kPa), the tractor and trailer spring brakes are automatically applied.

Emergency Braking

WARNING! Unless you have an anti-lock braking system, always avoid completely depressing the service brake pedal, if possible, even during emergency braking. Depressing the brake pedal too aggressively can cause the wheels to lock, which can lead to an uncontrolled skid and can result in an accident.

For Non-ABS Vehicles: To stop your vehicle in an emergency, vary the service brake application pressure to provide maximum braking force without locking the wheels. Use engine compression to assist the service brakes by not depressing the clutch pedal until the engine reaches idle speed.

Overheated Brakes

Under normal braking conditions, the e nergy generated will bring the internal brake drum temperature to about 500°F (260°C). This is well within the safe zone: the maximum safe temperature of lining for drum type brakes is usually about 800°F (427°C).

But if service brakes are used for emergency braking, used improperly, or for prolonged periods, internal brake drum temperatures may exceed 800°F (427°C). Such brake overheating may be detected by a b urning smell or smoke coming from a drum. If this occurs, you should immediately stop and check for crac k ed br ak e drums or lining fires. If neither exists, get back behind the wheel and resume a slow speed as soon as possible to cool the brakes. If the vehicle was to remain stopped, the heat transfer could destroy the linings and distort the brake drum.

– 80 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Using the Brake System

To prevent drums from distortion while they cool down:

• Park the vehicle on level surface and block the wheels.

• Release the parking brake and allow the brakes to cool down. See page 74

Anti-Lock Braking System

This vehicle may be equipped with an anti-lock braking system (ABS). This ABS reduces the possibility of wheel lockup. If a wheel is about to lock during braking, the ABS will automatically adjust air pressure to the brake chambers on the appropriate wheel(s) to prevent wheel lock-up. The ABS is automatically turned on when the ignition switch is turned on.

ABS Warning Lamps

Truck/Tractor ABS Warning Lamp

A truck/tractor ABS warning lamp illuminates when the ignition switch is first turned on and will remain on until the system self-test has been completed successfully. Normally, the

ABS lamp will remain on until a speed of no more than 9 mph has been reached and the speed sensors have been checked for correct output. The lamp should remain off after this point unless a failure in the system is de tected. The truck/tractor ABS lamp is located in the warning lamp cluster.

CAUTION: If the truck/tractor ABS warning light does not illuminate when the ignition is first turned on, there is a problem with the bulb or wiring. You should have this checked as soon as possible.

Medium Duty

(R10/06) Y53-6008 – 81 –

Using the Brake System Operating Instructions

Trailer ABS Warning Lamp

Trucks, tractors, and trailers built on and after March 1, 2001 are equipped with power line communication (PLC) per U.S. FMVSS 121, including a trailer ABS warning lamp in the cab.

ABS

CAUTION: If the trailer ABS warning lamp does not illuminate when the ignition is first turned on, there is a problem with the bulb or wiring. The driver should have this checked as soon as possible.

NOTE: A successsful warning lamp illumination and bulb check at ignition on does not trailer you may be connected to has trailer ABS . You should personally inspect every trailer to determine its braking system.

indicate that the

A trailer ABS warning lamp will illuminate for a bulb check when the ignition switch is first turned on - whether or not a trailer is connected to the vehicle. If the bulb check is satisfactory, the lamp will next do either of the following:

1. If no trailer is connected, or if a non-ABS-equipped trailer is connected, the trailer ABS lamp will go off after a few seconds.

NOTE: A “properly connected” ABS-equipped trailer is

• a trailer with PLC hooked up to the J560 connector.

• a trailer without PLC that is hooked up to an optional ISO 3731 connector.

NOTE: For doubles or triples: PLC does not dis-

tinguish between trailers. An ABS problem in any trailer will activate the trailer ABS warning lamp.

2. If an ABS-equipped trailer is properly connected, the trailer ABS warning lamp will remain illuminated for a few more seconds while the trailer ABS is tested.

• If no trailer ABS problems are detected, the lamp will go off.

– 82 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Using the Brake System

• If a trailer ABS problem is detected, the lamp will remain on. The driver should have the trailer’s ABS problem corrected before the vehicle is driven with that trailer attached.

WARNING! Do not rel y on an anti-lock brake system that is functioning improperly. You could lose control of the vehicle resulting in a severe accident and serious personal injury. If your ABS lamp goes on while you are drivin g or sta ys on after the self-check, your anti-lock system might not be working. The ABS may not fu nction in an emergency. You will still have conventional brakes, but not anti-lock brakes. If the lamp indicates a problem, have the ABS checked.

Wheel Spin Control Warning Lamp

Your ABS may have an acceleration slip regulation (ASR) or automatic traction control (ATC) feature. Either of these features is monitored by a wheel spin control warning lamp. This lamp is located in the warning lamp cluster.

The Wheel Spin Control warning lamp will briefly illuminate and then go out when the ignition switch is first turned on. The Wheel Spin Control warn ing lamp will illuminate whenever the ASR or ATC system detects drive wheel spin. The

lamp will remain illuminated as long as wheel spin is detected and the ASR or ATC system is applying the dr ive wheel brakes or reducing engine torque. Do not allow the Wheel Spin Control lamp to remain on continuously for an extended length of time. Extended, continuous use of the ASR / ATC can cause overheating of the drive wheel brakes. Engine torque or vehicle speed should be reduced to eliminate wheel spin and prevent excessive application of the ASR / ATC system.

Except for checking for proper illumination of the ABS and Wheel Spin Control warning lamps when first starting the truck and for monitoring these lamps while driving, no special operating procedures are required. For detailed system description, see ser vice literature for your specific ABS that was provided with your vehicle.

Trailer Brake Hand Valve

Tractor/trailer vehicles are equipped with a trailer brake hand valve mounted on the right side of the steering wheel column. This hand valve provides air pressure to apply the trailer brakes only. It operates independently of the foot treadle valve.

Medium Duty

(R10/06) Y53-6008 – 83 –

Using the Brake System Operating Instructions

To operate the trailer brake hand valve:

• Pull down on the lever.

• The valve is self-returning. When pressure is removed from the valve lever, it will return to the OFF position.

NOTE: The trailer brake is not to be used as a substitute for the service brakes. Using this brake frequently, instead of using the foot brake, will cause the trailer brakes to wear out sooner.

Driving Bobtail or With an Unloaded Trailer

NOTE: The following information is applicable only to tractor configurations.

Do not use the engine retarder (such as an exhaust brake) to slow the vehicle down when you are bobtailing or pulling an empty trailer.

WARNING! Do not use an engine retarder when you are driving bobtail or with an unloaded trailer. Using engine retarders while bobtailing or with an unloaded trailer can cause a wheel lockup resulting in less control and/or jackknife. The trailer may not load the rear tractor tires enough to provide necessary traction. When y ou are bobtail or unloaded, you can have a serious accident if your wheels lock suddenly during braking—you could be severely injured.

Bobtail Brake Proportioning System

When a trailer is not connected, the drive axle brake application pressure will automatically be limited by the proportioning system.

The brake proportioning system regulates the application pressure to the rear drive axle. To provide equivalent braking power, tractors (driven bobtail) will require greater brake pedal application than other types of vehicles not eq uipped with a proportioning system.

– 84 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Using the Brake System

On tractors that do not have anti-lock brake systems (ABS) a bobtail brake proportioning system is installed. When a trailer is not connected (bobtail mode), the brake application pressure (on the rear drive axle) will automatically be limited by the proportioning system.

Engine Retarder (option)

An engine retarder or exhaust brake may be installed (as an option) to create a braking effect on the drive wheels. This device uses your engine's power to slow your vehicle down. Because it can help keep your vehicle's brakes from overheating, it can save wear and tear on the service brakes. However, the retarder is not an emergency brake.

Ideally (on normal road surfaces), you should slow your v ehicle with the retarder (where permitted by law) and use the service brakes only for stopping completely. Operating this way will greatly prolong the life of the brakes.

WARNING! The service brakes must be used in an emergency. The engine or retarder alone might not stop you fast enough to prevent an accident. You could be badly hurt if you relied only on the engine retarder.

• The engine retarder is NOT intended as the primary brake for the vehicle, nor is it an emergency brake . The engine retarder only helps the service brakes b y using pressure to slow the drivetrain. Use the service brakes for quick stops.

Exhaust Brake

With the exhaust brake switch ON, the brake automatically creates its braking effect when you remo v e y our foot from the accelerator pedal.

The brake switch is located on the accessory dash panel. It controls whether the brake is ON (ready to slow the vehicle down) or OFF (no braking action).

• Do not use the engine retarder (such as an exhaust brake) to slow the vehicle down when you are bobtailing or pulling an empty trailer.

• Make sure the brake is OFF before starting the engine.

Medium Duty

(R10/06) Y53-6008 – 85 –

Using the Brake System Operating Instructions

• After the engine is started, warmed up, and you are ready to get under way, tur n the exhaust brake switch ON for added braking effect.

WARNING! Do not use the engine retard er when operating on road surfaces with poor traction (such as wet, icy, or snow covered roads or gravel). Retarders can cause the wheels to skid on a slippery surface. You could lose control of the vehicle and/or jackknife if the wheels begin to skid, resulting in an accident.

However, if your vehicle is equipped with Rockwell/WABCO anti-lock brakes (ABS), the operation of the exhaust brake (if turned ON) will be controlled by the ABS. For more ABS information, see “

For more information on when and how to use the engine retarder in your vehicle, see the owner’s manual for the engine brake that is included with your vehicle.

Anti-Lock Braking System” on page 81.

Brake Components

The following is a brief description of the air/brake system. It is intended to supply you with general information on how the system works. For complete information see the Medium

Duty Maintenance Manual. Compressor: supplies air to the system. System pressure is

controlled by the governor. Governor: controls the air pressure in the system by actuat-

ing the compressor discharge mechanism. Its cut-out pressure is 115 to 125 psi (793 to 862 kPa). Its preset cut-in pressure is set to between 13 to 25 psi (90 to 172 kP a) belo w the cut-out pressure setting (cut-out and cut-in interval is not adjustable).

Safety Valve: installed on the supply reservoir outlet. It should “vent off” at 150 psi (1034 kPa) permitting air to escape.

Air Dryer (Option): collects and removes moisture and contaminants from the air as it travels from the compressor to the wet tank (reservoir).

– 86 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Using the Brake System

Compressed Air Tanks: The wet (supply) and dry (service) tanks are located behind the batter y box and on the frame rail; the supply tank is below the front service tank. See “Air Tanks” on page 162

The wet tank receives air from the air dryer and cools it somewhat, allowing moisture to condense for draining. Relatively dry air is then supplied to the two service tanks for distribution to their respective brake circuits. The service tanks are isolated from each other by check valves.

Dual Service Brake Treadle Valve: delivers air to the two service brake circuits.

Double Check Va lve: directs the higher air pressure from either the rear (primar y) or front (se condar y) ser vice ta nk to the modulating valve.

Modulating Valve (SR–1): used only on full trucks, not tractors. It performs four functions:

• Limits spring brake hold-off air pressure delivered to the spring brake chambers.

• Provides a quick release of air pressure from the spring brake chambers to speed spring brake application.

• Modulates spring brake application in proportion to front service application in the event of a rear service failure.

• Prevents compounding of service and spring applications.

Relay valve (full truck): speeds up the application of the rear service brake. It also incorporates a quick–release feature.

Brake Proportioning (BP-R1) valve (tractor): this valve delivers air to the tractor's service brake chambers. It automatically proportions the drive axle brake app

lication pressure when driving bobtail (with out a trailer connected). Proportioning the brakes allows full use of the steer axle brakes and reduces lockup of the driv e axle brakes. The bobtail brake proportioning system is automatically turned off when a trailer is connected.

Quick–Release Valve:

brake chambers. When air is released, the air in the brake chambers is exhausted at the quick-release valve, rather than exhausting back through the treadle valve.

speeds the release of air from the

Medium Duty

Single Check Valve: allows air flow in one direction only.

(R10/06) Y53-6008 – 87 –

Using the Brake System Operating Instructions

Parking Brake Valve: yellow diamond-shaped knob. It controls the application and release of the parking (spring) brakes of truck or tractor-trailer combinations or of the tractor alone. If the air system is being charged from zero pressure, the parking brake valve will not hold in the release position until the system pressure exceeds 60 psi (414 kPa), which is the pressure required to override the load of this valve's plunger return spring.

Trailer Supply Valve (tractor): The Red octagonal-shaped knob protects the tractor system; it functions in conjunction with the parking brake valve (yellow). The trailer supply valve is responsible for synchronizing the tr actor and tra iler parking and emergency brakes. If the air system is being charged from zero pressure, the trailer supply valv e will not hold in the applied position until the system pressure exceeds 50 psi (345 kPa). It automatically pops out and e xhausts air if supply air pressure drops below 60 psi (414 kPa).

Tractor Protection Valve: The functions of this valve are to (1) receive all pneumatic signals pertinent to the operation of the trailer brake system, (2) transmit these signals to the trailer, and (3) protect the tractor air supply in case of separ ation of the air lines connecting the tractor to the trailer.

Hydraulic Brakes

WARNING! Do not operate the vehicle in the event of a malfunction in any air or hydraulic circuit. Such a malfunction may prevent the brake system from operating properly, and could result in an injury accident. The vehicle should not be operated until the system is repaired and both braking circuits, including all pneumatic, hydraulic, and mechanical components are working properly.

Introduction

The operation of the vehicle's braking system is based on the principle of hydraulics. Hydraulic action begins when force is applied to the brake pedal. This force creates hydraulic pressure in the master cylinder and is amplified with assistance of a power booster. The supplemental boost in force is developed when pressurized power steering fluid from the steering pump presses on the master cylinder piston. As a safety precaution, the pressurized fluid from the master cylinder has two mutually independent circuits. The primary circuit sup plies the front wheels while the secondary circuit supplies the rear wheels. The displaced fluid from the master cylinder travels through brake pipes terminating at the wheel cylin-

– 88 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Using the Brake System

ders which actuate the brake pad mechanisms. Actuation of these mechanisms force the brake pads against the rotors to stop the wheels.

A reserve electric motor pump provides a redundant power source for the hydraulic booster in the e v ent normal flow from the power steering pump is interrupted. Manual braking is also available in the event both the power and reserve systems are inoperative.

WARNING! Never drive your vehicle with the parking brakes applied. Always release the parking brakes prior to moving the vehicle. Failure to disengage the parking brakes prior to moving your vehicle could result in excessive heat b uildup of the brakes and start a fire.

NOTE: Today’ s diesel electronic engines hav e significant torque and startability power at low RPM. Combinations of engine speed and available torque may over-power the vehicle’s parking brakes.

Brake Components

The following is a brief description of the hydr aulic br ak e system. It is intended to supply you with general information on how the system works. For complete information see the Peterbilt Medium Duty Maintenance Manual.

Anti-Lock Brake System (ABS) Modulator Valve Body:

adjusts brake fluid flow between the master cylinder and the wheel calipers to avoid wheel lockup.

ABS Warning Lamp: lights when the ABS controller detects wheel lock-up while driving and activates the ABS. Lights also when a fault in the ABS is detected.

Brake Fluid Reservoir: stores brake fluid and offers a place to replenish when needed.

Medium Duty

(R10/06) Y53-6008 – 89 –

Using the Brake System Operating Instructions

Brake Master Cylinder: translates brake pedal force into hydraulic fluid pressure in the primary and secondary circuits.

Brake Pedal: applies actuation force from operator's foot to the master cylinder pistons.

Brake Warning Lamp: illuminates when either power steering fluid flow is interrupted or when a pressu re differential is present in the primary and secondar y brake fluid pressure. Either case adversely affects braking operation.

Differential Switch: measures the hydraulic fluid pressure difference between the primary and secondary circuits.

Electrohydraulic Pump: The Electrohydraulic (EH) pump is used as a backup boost pump. The EH pump turns on and provides fluid pressure to the hydraulic booster in the event power steering fluid stops flowing through the booster head.

Front and Rear Wheel Calipers: translate hydraulic fluid pressure into force applied at each wheel-end brake rotor to retard wheel motion.

Hydraulic Booster: The hydraulic booster applies additional hydraulic force from the power steering gear to the master cylinder piston when the brake pedal is applied.

Parking Brake Lamp: illuminates when the parking brake is engaged (the lever is in the up position.)

Parking Brake Lever: the hand lever located in the cab which engages or disengages the driveline drum brake.

Power Steering Flow Switc h: senses flow of pow er steering fluid.

Power Steerin g Fluid Reservo ir: stores power steering fluid and offers a place to replenish when needed.

Power Steering Gear: assists the steering operation and sends pressurized power steering fluid to the brake booster.

Power Steering Pump: draws power steering fluid from the reservoir and sends it to the power steering gear.

War n i n g Buzzer: sounds when either power steering fluid flow is interrupted or when a pressure differential is present between the primary and secondary brake fluid pressure. Either case adversely affects braking operation.

– 90 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Using the Brake System

Brake Warning Lamp

When the brake warning lamp comes on, it indicates a malfunction in the brake system. Possible malfunctions include loss of hydraulic pressure from the power steering circuit or a

MIRROR

HEAT

pressure differential between the primary and secondary brake circuits.

OIL

LOW

WATER

WARNING! Do not operate the vehicle if the brake light or buzzer comes on. The light or buzzer indicates a failure in one of the brake components/system. Drive your vehicle to the

BRAKE

WATER

side of the road immediately. Failure to do this may lead to an accident and severe injury.

SERVICE BRAKE WARNING INDICATOR

If the buzzer sounds while driving, or if the BRAKE light comes on, do the following:

1. Slow down carefully. Here are some things you can do to assist in slowing

the vehicle:

• Downshift - Putting the transmission into a lower gear will help slow the vehicle.

Medium Duty

(R10/06) Y53-6008 – 91 –

Using the Brake System Operating Instructions

• Pump the brakes - Pumping the brake pedal may generate enough hydraulic pressure to stop the vehicle.

• Use the parking brake - The parking or emergency brake is separate from the hydraulic system. Therefore it can be used to slow the vehicle.

2. Move a safe distance off the road and stop.

3. Set the parking brake. (See page 36

4. Turn on the emergency flasher and use other warning devices to alert other motorists.

Wet or Overheated Brakes

• Wet Brakes If you have been driving in heavy rain or deep stand-

ing water, your brakes will get wet. Water in the brakes can cause them to be weak, to apply unevenly, or to grab. These conditions can cause a lack of braking power, wheel lockups, or pulling of the vehicle to one side or the other.

Avoid driving through deep puddles or flowing w ater if possible. If not possible, you should to the following:

• Slow down.

• Place transmission in lower gear.

• Gently press on the brake pedal.

• Increase engine speed while keeping light pressure on the brake pedal for a short distance to dry out the brake linings.

• Overheated Brakes While traveling down steep hills, gravity will tend to

speed you up. You must go slow enough that your brakes can hold you back without getting too hot. If you ride the brake pedal and the brakes get too hot, they may “fade”, causing you to press even harder in an attempt to maintain your desired stopping power. The brakes may e ven fade so much that you won’t be able to slow down or stop at all.

Using lower transmission gears will help keep the vehicle from going too fast. Using lower gears allo ws engine compression and friction to help slow the vehicle. Be sure to be in the right gear before you start down a hill, especially if you have a manual transmission. You could get hung up in NEUTRAL and lose the benefit of engine braking. “Coasting” is illegal, and also VERY dangerous.

– 92 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Using the Brake System

Anti-Lock Braking System

This vehicle is equipped with an Anti-Lock Braking System (ABS). ABS reduces the likelihood of a wheel locking. If a wheel is about to lock during braking, the ABS will automatically adjust hydraulic pressure to the brake calipers on the appropriate wheel(s) to prevent wheel lock-up. The ABS is automatically activated when the ignition switch is turned on.

CAUTION: The center pin of the 7-wa y trailer light line may be constantly powered for ABS. Make sure it will not accidently turn on trailer equipment.

ABS Warning Lamp

The ABS warning lamp will come on briefly , then go off, when the key switch is first turned on. If the lamp remains ON until a speed of 4 mph (6 km/h) is reached, then goes OFF, there may be a stored fault code. If the lamp remains ON when a speed in excess of 4 mph (6 km/h) is reached, there may be an active fault in the ABS system.

CAUTION: If the ABS warning light does not illuminate when the ignition is first turned on, there is a problem with the bulb or wiring. You shou ld have this checked as soon as possible.

MIRROR

HEAT

OIL

LOW

WATER

BRAKE

ABS WARNING INDICATOR

WARNING! No indication will be given via the dashboard warning lights or buzzer if tires of the wrong size are installed on your vehicle. The Anti-Lock Brake System (ABS) is calibrated for the specific tire revolutions per mile. Use of a tire and/or wheel size different from that originally installed on your vehicle may cause the ABS system to not function during a hard braking event. This could cause an accident or serious personal injury. Consult with your Peterbilt dealer before using a different tire and/or wheel size than was originally installed on your vehicle.

Medium Duty

(R10/06) Y53-6008 – 93 –

Using the Brake System Operating Instructions

Parking Brake Burnishing

This procedure is recommended for new vehicles where less lever actuation force is required. This procedure is manda- tory whenever the driveline brake shoes or brake drum are replaced.

WARNING! If a new drum or new brake shoes are installed, the driveline brake must be burnished. Failure to properly burnish the parking brake before putting it in service could result in an inoperative parking brake, possible vehicle rollaway, and serious personal injury or damage to the vehicle.

1. Drive the vehicle at 15 mph (24 km/h) in a low gear (first or second) on a dry, hard road surface.

2. Apply the parking brake lever with a moderate force (approximately 40 pounds) until the vehicle is brought to a stop. Do not allow the wheels to loc k up .

3. After stopping, release the parking brake lever and drive the vehicle at 20 mph (32 km/h) in a low gear for approximately 2.5 miles, to allow the brake drum to cool.

4. Repeat steps 1, 2, and 3 above until a total of 10 stops have been completed.

5. Adjust the parking brake lever. See the Medium Duty Maintenance Manual.

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Medium Duty (R10/06)

Operating Instructions Operating the Rear/Drive Axle

OPERATING THE REAR/DRIVE AXLE

Introduction

This section covers the operation of your Rear/Drive Axle. These instructions apply to the most commo n features of drive axles. Refer to the manufacturer’s instructions for further information on the operation of your axle.

If your vehicle is equipped with a Rockwell Tractech™ Nospin single rear axle, the wheel differential lock feature automatically engages and disengages. When one wheel st ar ts to spin on a slippery surface, this rear axle feature engages to improve traction.

Interaxle Differential Lock

On vehicles with tandem rear axles, the interaxle differential allows each axle to turn independently. Differential action between the tandems relieves stress on the rear axles and reduces tire wear. The interaxle diff erential loc k s witch allo ws the operator to LOCK or UNLOCK the differential, depending on road surface conditions.

When operating normally on paved, dry surfaces, keep your truck's interaxle differential in the UNLOCK position.

GUARD

Interaxle Differential Lock Switch in normal (unlocked) position

Interaxle

Differential Lock Switch in locked position

Medium Duty

(R10/06) Y53-6008 – 95 –

Operating the Rear/Drive Axle Operating Instructions

In the LOCK position, an air operated clutch positively locks both sets of axles together, providing greater traction on slippery road surfaces; howev er, steering around corners and on dry pavement is more difficult. Continuous operation on a paved, dry surface stresses the tandem axles, possib ly causing internal damage.

Use this feature only when driving on surfaces with poor traction, such as wet slippery roads, heavy mud or snow , or loose gravel. And do not use it when going downhill or at speeds greater than 25 mph (40 km/h).

Lock the ditions such as these:

inter-axle differential when you encounter road con-

• Ice or snow — with or without tire chains.

• Dirt roads.

• Loose sand, mud, or other rough road conditions.

WARNING! Do not put the differential lock in the LOCK position while the wheels are spinning freely (slipping), you could lose control of the vehicle or cause axle damage—you could be injured. Switch to LOCK only when the wheels are not spinning.

• Look ahead for wet, muddy, or icy patches on the road, stop your vehicle and switch to LOCK ahead of time.

WARNING! Do not operate the vehicle on dry pavement with the differential locked. This could lead to an injury accident. On dry pavement, you will not be able to steer well with the differential locked. Lock the differential only when operating on surfaces with poor traction, such as wet, slippery roads or loose gravel.

Inter–Axle Differential Lock Operation

WARNING! Do not use the inter-axle differential lock when travelling downhill or at speeds abo ve 25 mph (40 km/h). When it is engaged under these conditions, your vehicle will exhibit “understeer” handling characteristics. This “understeer” condition will cause your vehicle to turn less quickly and more steering effort will be required, which can cause an injury accident.

To LOCK the inter-axle differential:

1. Anticipate when you might need increased traction, slow down to a steady speed under 25 mph (40 km/h) or stop the vehicle. Do not lock the inter-axle differential while

– 96 – Y53-6008

Medium Duty (R10/06)

Operating Instructions Operating the Rear/Drive Axle

going down steep grades or tra veling f aster than 25 mph, or while wheels are spinning or traction is minimal; lock it before you encounter these conditions.

Turning Radius When Unlocked (Disengaged)

Turning Radius When Locked (Engaged)

02871

Understeer Condition

2. Put the inter-axle differential lock switch, labeled MAIN DIFFERENTIAL LOCK, in the LOCK position. A light (DIFF LOCK) in the warning module on the dash will turn on, indicating that the differential is locked (engaged).

3. If you LOCK or UNLOCK the inter-axle differential while moving, let up momentarily on the accelerator pedal to relieve torque on the gearing and allow full engagement of the clutch (the mechanism that locks the wheels).

NOTE: If your vehicle has an automatic transmission, it may be necessary to shift the transmission to the Neutral position momentarily to allow the main inter-axle differential lock splines to fully engage or disengage.

4. Drive the vehicle through the poor traction area, keeping your speed under 25 mph (40 km/h).

To UNLOCK the inter-axle differential:

1. When you reach dry pavement or better road conditions where the differential lock is not needed, switch the differential lock to UNLOCK.

2. Let up momentarily on the accelerator pedal to relieve torque and allow the clutch to disengage.

3. When you unlock the differential, normal vehicle handling will resume and the light on the warning module will turn off.

Medium Duty

(R10/06) Y53-6008 – 97 –

More Driving Tips and Techniques Operating Instructions

MORE DRIVING TIPS AND

TECHNIQUES

WARNING! Low air pressure could make the brakes unsafe for driving. Before driving the vehicle, make sure the pressure does pump up to over 100 psi for normal brake operation. If the air pressure does not pump up to at least 100 psi, don’t try to move the vehicle.

CAUTION: Operating a vehicle with air suspension bags either overinflated or underinflated may cause damage to driveline components. If a vehicle must be operated under such conditions, do not exceed 5 mph.

Driving Tips And Techniques

This section covers additional driving tips and techniques on how to drive your vehicle more efficiently. For fur ther information, read the American Trucking Association's (ATA) Truck Driver's Handbook. It will give you more tips on starting, shifting, and driving your vehicle.

Coasting

WARNING! Do not coast with the transmission in neutral or with the clutch pedal depressed—it is a dangerous practice. Without the use of the retarding power of the drivetrain, your vehicle can reach dangerous speeds. At very high speeds you may not be able to put the transmission in any gear. At high speeds you could seriousl y damage you r vehicle or cause an accident whe n you put the transmission in gear. The engine speed could exceed the maximum governed speed and cause a serious accident due to mechanical failures.

Do not coast with the transmission in neutral or with the clutch pedal depressed. Besides being illegal and dangerous, coasting is also expensive. It causes premature failure or damage to the clutch and transmission and overloads the brake system.

Coasting with the transmission in neutral also prevents proper transmission component lubrication. During coasting the transmission is driven by the rear wheels, and the

– 98 – Y53-6008

Medium Duty (R10/06)

Peterbilt Y53-6008 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual