Dodge Cooling Service Manual

BR/BE COOLING 7 - 1

COOLING

TABLE OF CONTENTS

page page

COOLING

DESCRIPTION

DESCRIPTION - COOLING SYSTEM FLOW -

5.9L ENGINE ..........................1

DESCRIPTION—COOLING SYSTEM FLOW -

5.9L DIESEL ..........................2

DESCRIPTION—HOSE CLAMPS ...........4

OPERATION

OPERATION—HOSE CLAMPS ............4

OPERATION—COOLING SYSTEM .........4

DIAGNOSIS AND TESTING

DIAGNOSIS AND TESTING - PRELIMINARY

CHECKS .............................4

DIAGNOSIS AND TESTING—ON-BOARD

DIAGNOSTICS (OBD) ...................5

DIAGNOSIS AND TESTING - COOLING

SYSTEM LEAKS .......................5

DIAGNOSIS AND TESTING - COOLING

SYSTEM GAS ENGINE ..................7

DIAGNOSIS AND TESTING - COOLING

SYSTEM DIESEL ENGINE ...............13

STANDARD PROCEDURE

STANDARD PROCEDURE - DRAINING

COOLING SYSTEM 5.9L/8.0L ENGINES ....15

STANDARD PROCEDURE—DRAINING

COOLING SYSTEM 5.9L DIESEL ENGINE . . . 15

STANDARD PROCEDURE - REFILLING

COOLING SYSTEM 5.9L/8.0L ENGINES ....16

STANDARD PROCEDURE—REFILLING

COOLING SYSTEM 5.9L DIESEL ENGINE . . . 16

STANDARD PROCEDURE - ADDING

ADDITIONAL COOLANT.................16

STANDARD PROCEDURE—COOLANT

LEVEL CHECK........................16

STANDARD PROCEDURE - COOLING

SYSTEM CLEANING/REVERSE FLUSHING . . 17

STANDARD PROCEDURE - COOLANT

SELECTION - ADDITIVES ...............17

SPECIFICATIONS

TORQUE ............................18

SPECIAL TOOLS

COOLING ...........................18

ACCESSORY DRIVE ......................19

ENGINE ...............................38

TRANSMISSION .........................78

COOLING

DESCRIPTION

DESCRIPTION - COOLING SYSTEM FLOW -

5.9L ENGINE

The cooling system regulates engine operating temperature. It allows the engine to reach normal operating temperature as quickly as possible. It also maintains normal operating temperature and prevents overheating.

The cooling system also provides a means of heating the passenger compartment and cooling the automatic transmission fluid (if equipped). The cooling system is pressurized and uses a centrifugal water pump to circulate coolant throughout the system.

An optional factory installed maximum duty cooling package is available on most models. This package will provide additional cooling capacity for vehicles used under extreme conditions such as trailer towing in high ambient temperatures (Fig. 1).

7 - 2 COOLING BR/BE

COOLING (Continued)

Fig. 1 Engine Cooling System Flow

1 - HEATER 2 - BYPASS*

DESCRIPTION—COOLING SYSTEM FLOW -

5.9L DIESEL

The diesel engine cooling system consists of (Fig.

2):

• Cross-flow radiator

• Belt driven water pump

• Belt driven mechanical cooling fan

• Thermal viscous fan drive

• Fan shroud

• Radiator pressure cap

• Vertically mounted thermostat

• Coolant reserve/recovery system

• Transmission oil cooler

• Coolant

Coolant flow circuits for the 5.9L diesel engine are

shown in (Fig. 3).

3 - CROSSFLOW RADIATOR

Fig. 2 Cooling System Components 5.9L Diesel

Engine

1 - RADIATOR CAP 2 - AUXILIARY TRANSMISSION OIL COOLER 3 - CHARGE AIR COOLER 4 - RADIATOR LOWER HOSE 5 - OVERFLOW/RESERVOIR BOTTLE 6 - FAN SHROUD 7 - RADIATOR UPPER HOSE 8 - CONSTANT TENSION CLAMP

BR/BE COOLING 7 - 3

COOLING (Continued)

Fig. 3 Cooling System Circulation—Diesel Engine

7 - 4 COOLING BR/BE

COOLING (Continued)

DESCRIPTION—HOSE CLAMPS

The cooling system utilizes both worm drive and spring type hose clamps. If a spring type clamp replacement is necessary, replace with the original Mopart equipment spring type clamp.

CAUTION: A number or letter is stamped into the tongue of constant tension clamps. If replacement is necessary, use only a original equipment clamp with matching number or letter (Fig. 4).

age will provide additional cooling capacity for vehicles used under extreme conditions such as trailer towing in high ambient temperatures.

DIAGNOSIS AND TESTING

DIAGNOSIS AND TESTING - PRELIMINARY CHECKS

ENGINE COOLING SYSTEM OVERHEATING

Establish what driving conditions caused the complaint. Abnormal loads on the cooling system such as the following may be the cause:

• PROLONGED IDLE

• VERY HIGH AMBIENT TEMPERATURE

• SLIGHT TAIL WIND AT IDLE

• SLOW TRAFFIC

• TRAFFIC JAMS

• HIGH SPEED OR STEEP GRADES

Driving techniques that avoid overheating are:

• Idle with A/C off when temperature gauge is at

end of normal range.

• Increasing engine speed for more air flow is rec-

ommended.

Fig. 4 Spring Clamp Size Location

1 - SPRING CLAMP SIZE LOCATION

OPERATION

OPERATION—HOSE CLAMPS

The worm type hose clamp uses a specified torque value to maintain proper tension on a hose connection.

The spring type hose clamp applies constant tension on a hose connection. To remove a spring type hose clamp, only use constant tension clamp pliers designed to compress the hose clamp.

OPERATION—COOLING SYSTEM

An optional factory installed maximum duty cooling package is available on most models. This pack-

TRAILER TOWING:

Consult Trailer Towing section of owners manual.

Do not exceed limits.

AIR CONDITIONING; ADD-ON OR AFTER MARKET:

A maximum cooling package should have been ordered with vehicle if add-on or after market A/C is installed. If not, maximum cooling system components should be installed for model involved per manufacturer’s specifications.

RECENT SERVICE OR ACCIDENT REPAIR:

Determine if any recent service has been performed on vehicle that may effect cooling system. This may be:

• Engine adjustments (incorrect timing)

• Slipping engine accessory drive belt(s)

• Brakes (possibly dragging)

• Changed parts. Incorrect water pump or pump

rotating in wrong direction due to belt not correctly routed

• Reconditioned radiator or cooling system refill-

ing (possibly under filled or air trapped in system).

NOTE: If investigation reveals none of the previous items as a cause for an engine overheating complaint, (Refer to 7 - COOLING - DIAGNOSIS AND TESTING)

BR/BE COOLING 7 - 5

COOLING (Continued)

DIAGNOSIS AND TESTING—ON-BOARD DIAGNOSTICS (OBD)

COOLING SYSTEM RELATED DIAGNOSTICS

The powertrain control module (PCM) has been programmed to monitor certain cooling system components:

• If the engine has remained cool for too long a period, such as with a stuck open thermostat, a Diagnostic Trouble Code (DTC) can be set.

• If an open or shorted condition has developed in the relay circuit controlling the electric radiator fan, a Diagnostic Trouble Code (DTC) can be set.

If the problem is sensed in a monitored circuit often enough to indicated an actual problem, a DTC is stored. The DTC will be stored in the PCM memory for eventual display to the service technician. (Refer to 25 - EMISSIONS CONTROL - DESCRIPTION).

ACCESSING DIAGNOSTIC TROUBLE CODES

To read DTC’s and to obtain cooling system data, (Refer to 25 - EMISSIONS CONTROL - DESCRIPTION).

Fig. 5 Leak Detection Using Black Light—Typical

1 - TYPICAL BLACK LIGHT TOOL

ERASING TROUBLE CODES

After the problem has been repaired, use the DRB scan tool to erase a DTC. Refer to the appropriate Powertrain Diagnostic Procedures service information for operation of the DRB scan tool.

DIAGNOSIS AND TESTING - COOLING SYSTEM LEAKS

ULTRAVIOLET LIGHT METHOD

A leak detection additive is available through the parts department that can be added to cooling system. The additive is highly visible under ultraviolet light (black light). Pour one ounce of additive into cooling system. Place heater control unit in HEAT position. Start and operate engine until radiator upper hose is warm to touch. Aim the commercially available black light tool at components to be checked. If leaks are present, black light will cause additive to glow a bright green color.

The black light can be used in conjunction with a pressure tester to determine if any external leaks exist (Fig. 5).

PRESSURE TESTER METHOD

The engine should be at normal operating temperature. Recheck the system cold if cause of coolant loss is not located during the warm engine examination.

WARNING: HOT, PRESSURIZED COOLANT CAN CAUSE INJURY BY SCALDING.

Carefully remove radiator pressure cap from filler neck and check coolant level. Push down on cap to disengage it from stop tabs. Wipe inside of filler neck and examine lower inside sealing seat for nicks, cracks, paint, dirt and solder residue. Inspect radiator-to- reserve/overflow tank hose for internal obstructions. Insert a wire through the hose to be sure it is not obstructed.

Inspect cams on outside of filler neck. If cams are damaged, seating of pressure cap valve and tester seal will be affected.

Attach pressure tester (7700 or an equivalent) to radiator filler neck (Fig. 6).

Operate tester pump to apply 103.4 kPa (15 psi) pressure to system. If hoses enlarge excessively or bulges while testing, replace as necessary. Observe gauge pointer and determine condition of cooling system according to following criteria:

Holds Steady: If pointer remains steady for two minutes, serious coolant leaks are not present in system. However, there could be an internal leak that does not appear with normal system test pressure. If it is certain that coolant is being lost and leaks cannot be detected, inspect for interior leakage or perform Internal Leakage Test.

Drops Slowly: Indicates a small leak or seepage is occurring. Examine all connections for seepage or slight leakage with a flashlight. Inspect radiator,

7 - 6 COOLING BR/BE

COOLING (Continued)

combustion leak exists. This is usually the result of a cylinder head gasket leak or crack in engine. Repair as necessary.

If there is not an immediate pressure increase, pump the Pressure Tester. Do this until indicated pressure is within system range of 110 kPa (16 psi). Fluctuation of gauge pointer indicates compression or combustion leakage into cooling system.

Because the vehicle is equipped with a catalytic converter, do not remove spark plug cables or short out cylinders to isolate compression leak.

If the needle on dial of pressure tester does not fluctuate, race engine a few times to check for an abnormal amount of coolant or steam. This would be emitting from exhaust pipe. Coolant or steam from

Fig. 6 Pressure Testing Cooling System—Typical

1 - TYPICAL COOLING SYSTEM PRESSURE TESTER

hoses, gasket edges and heater. Seal small leak holes with a Sealer Lubricant (or equivalent). Repair leak holes and inspect system again with pressure applied.

Drops Quickly: Indicates that serious leakage is occurring. Examine system for external leakage. If leaks are not visible, inspect for internal leakage. Large radiator leak holes should be repaired by a reputable radiator repair shop.

INTERNAL LEAKAGE INSPECTION

Remove engine oil pan drain plug and drain a small amount of engine oil. If coolant is present in the pan, it will drain first because it is heavier than oil. An alternative method is to operate engine for a short period to churn the oil. After this is done, remove engine dipstick and inspect for water globules. Also inspect transmission dipstick for water globules and transmission fluid cooler for leakage.

WARNING: WITH RADIATOR PRESSURE TESTER TOOL INSTALLED ON RADIATOR, DO NOT ALLOW PRESSURE TO EXCEED 110 KPA (20 PSI). PRESSURE WILL BUILD UP QUICKLY IF A COMBUSTION LEAK IS PRESENT. TO RELEASE PRESSURE, ROCK TESTER FROM SIDE TO SIDE. WHEN REMOVING TESTER, DO NOT TURN TESTER MORE THAN 1/2 TURN IF SYSTEM IS UNDER PRESSURE.

Operate engine without pressure cap on radiator until thermostat opens. Attach a Pressure Tester to filler neck. If pressure builds up quickly it indicates a

exhaust pipe may indicate a faulty cylinder head gasket, cracked engine cylinder block or cylinder head.

A convenient check for exhaust gas leakage into cooling system is provided by a commercially available Block Leak Check tool. Follow manufacturers instructions when using this product.

COMBUSTION LEAKAGE TEST - WITHOUT PRESSURE TESTER

DO NOT WASTE reusable coolant. If solution is clean, drain coolant into a clean container for reuse.

WARNING: DO NOT REMOVE CYLINDER BLOCK DRAIN PLUGS OR LOOSEN RADIATOR DRAINCOCK WITH SYSTEM HOT AND UNDER PRESSURE. SERIOUS BURNS FROM COOLANT CAN OCCUR.

Drain sufficient coolant to allow thermostat removal. (Refer to 7 - COOLING/ENGINE/ENGINE COOLANT THERMOSTAT - REMOVAL). Remove accessory drive belt (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).

Add coolant to radiator to bring level to within 6.3 mm (1/4 in) of top of thermostat housing.

CAUTION: Avoid overheating. Do not operate engine for an excessive period of time. Open draincock immediately after test to eliminate boil over.

Start engine and accelerate rapidly three times, to approximately 3000 rpm while observing coolant. If internal engine combustion gases are leaking into cooling system, bubbles will appear in coolant. If bubbles do not appear, internal combustion gas leakage is not present.

BR/BE COOLING 7 - 7

COOLING (Continued)

DIAGNOSIS AND TESTING - COOLING SYSTEM GAS ENGINE

COOLING SYSTEM DIAGNOSIS—GASOLINE ENGINE

CONDITION POSSIBLE CAUSES CORRECTION

TEMPERATURE GAUGE READS LOW

1. Has a Diagnostic Trouble Code (DTC) been set indicating a stuck open thermostat?

2. Is the temperature sending unit connected?

3. Is the temperature gauge operating OK?

4. Coolant level low in cold ambient temperatures accompanied with poor heater performance.

5. Improper operation of internal heater doors or heater controls.

1. (Refer to 25 - EMISSIONS CONTROL - DESCRIPTION) for On-Board Diagnostics and DTC information. Replace thermostat if necessary.

2. Check the temperature sensor connector. (Refer to 8 ELECTRICAL/INSTRUMENT CLUSTER - SCHEMATIC ELECTRICAL) Repair connector if necessary.

3. Check gauge operation. (Refer to 8 - ELECTRICAL/INSTRUMENT CLUSTER/ENGINE TEMPERATURE GAUGE DESCRIPTION). Repair as necessary.

4. Check coolant level in the coolant reserve/overflow tank and the radiator. Inspect system for leaks. Repair leaks as necessary. Refer to the Coolant section of the manual text for WARNINGS and CAUTIONS associated with removing the radiator cap.

5. Inspect heater and repair as necessary. (Refer to 24 - HEATING & AIR CONDITIONING DIAGNOSIS AND TESTING) for procedures.

7 - 8 COOLING BR/BE

COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION

TEMPERATURE GAUGE READS HIGH OR THE COOLANT WARNING LAMP ILLUMINATES. COOLANT MAY OR MAY NOT BE LOST OR LEAKING FROM THE COOLING SYSTEM

1. Trailer is being towed, a steep hill is being climbed, vehicle is operated in slow moving traffic, or engine is being idled with very high ambient (outside) temperatures and the air conditioning is on. Higher altitudes could aggravate these conditions.

2. Is the temperature gauge reading correctly?

3. Is the temperature warning illuminating unnecessarily?

4. Coolant low in coolant reserve/ overflow tank and radiator?

5. Pressure cap not installed tightly. If cap is loose, boiling point of coolant will be lowered. Also refer to the following Step 6.

6. Poor seals at the radiator cap. 6. (a) Check condition of cap and

7. Coolant level low in radiator but not in coolant reserve/overflow tank. This means the radiator is not drawing coolant from the coolant reserve/overflow tank as the engine cools

1. This may be a temporary condition and repair is not necessary. Turn off the air conditioning and attempt to drive the vehicle without any of the previous conditions. Observe the temperature gauge. The gauge should return to the normal range. If the gauge does not return to the normal range, determine the cause for overheating and repair. Refer to Possible Causes (2-20).

2. Check gauge. (Refer to 8 ELECTRICAL/INSTRUMENT CLUSTER - SCHEMATIC ELECTRICAL). Repair as necessary.

3. (Refer to 8 - ELECTRICAL/ INSTRUMENT CLUSTER SCHEMATIC - ELECTRICAL).

4. Check for coolant leaks and repair as necessary. (Refer to 7 COOLING - DIAGNOSIS AND TESTING).

5. Tighten cap

cap seals. Refer to Radiator Cap. Replace cap if necessary.

(b) Check condition of radiator filler neck. If neck is bent or damaged, replace radiator.

7. (a) Check condition of radiator cap and cap seals. Refer to Radiator Cap in this Group. Replace cap if necessary.

(b) Check condition of radiator filler neck. If neck is bent or damaged, replace radiator.

(c) Check condition of the hose from the radiator to the coolant tank. It should fit tight at both ends without any kinks or tears. Replace hose if necessary.

(d) Check coolant reserve/overflow tank and tanks hoses for blockage. Repair as necessary.

BR/BE COOLING 7 - 9

COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION

8. Incorrect coolant concentration 8. Check coolant. (Refer to LUBRICATION & MAINTENANCE/ FLUID TYPES - DESCRIPTION).

9. Coolant not flowing through

system

10. Radiator or A/C condenser fins

are dirty or clogged.

11. Radiator core is corroded or

plugged.

12. Aftermarket A/C installed

without proper radiator.

13. Fuel or ignition system

problems.

14. Dragging brakes. 14. Check and correct as

15. Bug screen or cardboard is

being used, reducing airflow.

16. Thermostat partially or

completely shut.

17. Viscous fan drive not operating

properly.

18. Cylinder head gasket leaking. 18. Check for cylinder head gasket

19. Heater core leaking. 19. Check heater core for leaks.

9. Check for coolant flow at radiator filler neck with some coolant removed, engine warm and thermostat open. Coolant should be observed flowing through radiator. If flow is not observed, determine area of obstruction and repair as necessary.

10. Remove insects and debris. (Refer to 7 - COOLING STANDARD PROCEDURE).

11. Have radiator re-cored or replaced.

12. Install proper radiator.

13. Refer to 14 - Fuel System or 8 Electrical for diagnosis and testing procedures.

necessary. (Refer to 5 - BRAKES DIAGNOSIS AND TESTING) for correct procedures.

15. Remove bug screen or cardboard.

16. Check thermostat operation and replace as necessary. (Refer to 7 COOLING/ENGINE/ENGINE COOLANT THERMOSTAT REMOVAL).

17. Check fan drive operation and replace as necessary. (Refer to 7 COOLING/ENGINE/FAN DRIVE VISCOUS CLUTCH - REMOVAL).

leaks. (Refer to 7 - COOLING DIAGNOSIS AND TESTING).

(Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING DIAGNOSIS AND TESTING). Repair as necessary.

7 - 10 COOLING BR/BE

COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION

TEMPERATURE GAUGE READING IS INCONSISTENT (FLUCTUATES, CYCLES OR IS ERRATIC)

1. During cold weather operation,

with the heater blower in the high position, the gauge reading may drop slightly.

2. Temperature gauge or engine

mounted gauge sensor defective or shorted. Also, corroded or loose wiring in this circuit.

3. Gauge reading rises when

vehicle is brought to a stop after heavy use (engine still running)

4. Gauge reading high after

re-starting a warmed up (hot) engine.

5. Coolant level low in radiator (air

will build up in the cooling system causing the thermostat to open late).

6. Cylinder head gasket leaking

allowing exhaust gas to enter cooling system causing a thermostat to open late.

7. Water pump impeller loose on

shaft.

8. Loose accessory drive belt.

(water pump slipping)

9. Air leak on the suction side of

the water pump allows air to build up in cooling system causing thermostat to open late.

1. A normal condition. No correction is necessary.

2. Check operation of gauge and repair if necessary. (Refer to 8 ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING).

3. A normal condition. No correction is necessary. Gauge should return to normal range after vehicle is driven.

4. A normal condition. No correction is necessary. The gauge should return to normal range after a few minutes of engine operation.

5. Check and correct coolant leaks. (Refer to 7 - COOLING DIAGNOSIS AND TESTING).

6. (a) Check for cylinder head gasket leaks. (Refer to 7 COOLING - DIAGNOSIS AND TESTING).

(b) Check for coolant in the engine oil. Inspect for white steam emitting from the exhaust system. Repair as necessary.

7. Check water pump and replace as necessary. (Refer to 7 COOLING/ENGINE/WATER PUMP REMOVAL).

8. (Refer to 7 - COOLING/ ACCESSORY DRIVE/DRIVE BELTS

- DIAGNOSIS AND TESTING). Check and correct as necessary.

9. Locate leak and repair as necessary.

PRESSURE CAP IS BLOWING OFF STEAM AND/OR COOLANT TO COOLANT TANK. TEMPERATURE GAUGE READING MAY BE ABOVE NORMAL BUT NOT HIGH. COOLANT LEVEL MAY BE HIGH IN COOLANT RESERVE/ OVERFLOW TANK

1. Pressure relief valve in radiator

cap is defective.

1. Check condition of radiator cap and cap seals. (Refer to 7 COOLING/ENGINE/RADIATOR PRESSURE CAP - DIAGNOSIS AND TESTING). Replace cap as necessary.

BR/BE COOLING 7 - 11

COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION

COOLANT LOSS TO THE GROUND WITHOUT PRESSURE CAP BLOWOFF. GAUGE READING HIGH OR HOT

DETONATION OR PRE-IGNITION (NOT CAUSED BY IGNITION SYSTEM). GAUGE MAY OR MAY NOT BE READING HIGH

HOSE OR HOSES COLLAPSE WHILE ENGINE IS RUNNING

1. Coolant leaks in radiator, cooling

system hoses, water pump or engine.

1. Engine overheating. 1. Check reason for overheating

2. Freeze point of coolant not

correct. Mixture is too rich or too lean.

1. Vacuum created in cooling

system on engine cool-down is not being relieved through coolant reserve/overflow system.

1. Pressure test and repair as necessary. (Refer to 7 - COOLING DIAGNOSIS AND TESTING).

and repair as necessary.

2. Check coolant concentration. (Refer to LUBRICATION & MAINTENANCE/FLUID TYPES DESCRIPTION).

1. (a) Radiator cap relief valve stuck. (Refer to 7 - COOLING/ ENGINE/RADIATOR PRESSURE CAP - DIAGNOSIS AND TESTING). Replace if necessary

(b) Hose between coolant reserve/overflow tank and radiator is kinked. Repair as necessary.

(d) Reserve/overflow tank is internally blocked or plugged. Check for blockage and repair as necessary.

NOISY VISCOUS FAN/DRIVE 1. Fan blades loose. 1. Replace fan blade assembly.

(Refer to 7 - COOLING/ENGINE/ RADIATOR FAN - REMOVAL)

2. Fan blades striking a surrounding

object.

3. Air obstructions at radiator or air

conditioning condenser.

4. Thermal viscous fan drive has

defective bearing.

5. A certain amount of fan noise

may be evident on models equipped with a thermal viscous fan drive. Some of this noise is normal.

2. Locate point of fan blade contact and repair as necessary.

3. Remove obstructions and/or clean debris or insects from radiator or A/C condenser.

4. Replace fan drive. Bearing is not serviceable. (Refer to 7 - COOLING/ ENGINE/FAN DRIVE VISCOUS CLUTCH - REMOVAL).

5. (Refer to 7 - COOLING/ENGINE/ FAN DRIVE VISCOUS CLUTCH DESCRIPTION) for an explanation of normal fan noise.

7 - 12 COOLING BR/BE

COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION

INADEQUATE HEATER PERFORMANCE. THERMOSTAT FAILED IN OPEN POSITION

STEAM IS COMING FROM THE FRONT OF VEHICLE NEAR THE GRILL AREA WHEN WEATHER IS WET, ENGINE IS WARMED UP AND RUNNING, AND VEHICLE IS STATIONARY. TEMPERATURE GAUGE IS IN NORMAL RANGE

1. Has a Diagnostic trouble Code

(DTC) been set?

2. Coolant level low 2. (Refer to 7 - COOLING -

3. Obstructions in heater hose/

fittings

4. Heater hose kinked 4. Locate kinked area and repair as

5. Water pump is not pumping

water to/through the heater core. When the engine is fully warmed up, both heater hoses should be hot to the touch. If only one of the hoses is hot, the water pump may not be operating correctly or the heater core may be plugged. Accessory drive belt may be slipping causing poor water pump operation.

1. During wet weather, moisture

(snow, ice or rain condensation) on the radiator will evaporate when the thermostat opens. This opening allows heated water into the radiator. When the moisture contacts the hot radiator, steam may be emitted. This usually occurs in cold weather with no fan or airflow to blow it away.

1. (Refer to 25 - EMISSIONS CONTROL - DESCRIPTION) for correct procedures and replace thermostat if necessary

DIAGNOSIS AND TESTING).

3. Remove heater hoses at both ends and check for obstructions

necessary

5. (Refer to 7 - COOLING/ENGINE/ WATER PUMP - REMOVAL). If a slipping belt is detected, (Refer to 7

- COOLING/ACCESSORY DRIVE/DRIVE BELTS - DIAGNOSIS AND TESTING). If heater core obstruction is detected, (Refer to 24

- HEATING & AIR CONDITIONING/ PLUMBING/HEATER CORE REMOVAL).

1. Occasional steam emitting from this area is normal. No repair is necessary.

COOLANT COLOR 1. Coolant color is not necessarily

an indication of adequate corrosion or temperature protection. Do not rely on coolant color for determining condition of coolant.

COOLANT LEVEL CHANGES IN COOLANT RESERVE/OVERFLOW TANK. TEMPERATURE GAUGE IS IN NORMAL RANGE

1. Level changes are to be

expected as coolant volume fluctuates with engine temperature. If the level in the tank was between the FULL and ADD marks at normal operating temperature, the level should return to within that range after operation at elevated temperatures.

1. (Refer to LUBRICATION & MAINTENANCE/FLUID TYPES DESCRIPTION). Adjust coolant mixture as necessary.

1. A normal condition. No repair is necessary.

BR/BE COOLING 7 - 13

COOLING (Continued)

DIAGNOSIS AND TESTING - COOLING SYSTEM DIESEL ENGINE

COOLING SYSTEM DIAGNOSIS—DIESEL ENGINE

CONDITION POSSIBLE CAUSES CORRECTION

TEMPERATUREGAUGE READS LOW

TEMPERATURE GAUGE READS HIGH. COOLANT MAY OR MAY NOT BE LEAKING FROM SYSTEM

1. Vehicle is equipped with a heavy

duty cooling system.

2. Temperature gauge not

connected

3. Temperature gauge connected

but not operating.

4. Coolant level low. 4. Fill cooling system. (Refer to 7 -

1. Vehicle overloaded, high ambient

(outside) temperatures with A/C turned on, stop and go driving or prolonged operation at idle speeds.

2. Temperature gauge not

functioning correctly.

3. Air traped in cooling 3. Drain cooling system (Refer to 7 -

4. Radiator cap faulty. 4. Replace radiator cap.

5. Plugged A/C or radiator cooling

fins.

6. Coolant mixture incorrect. 6. Drain cooling system (Refer to 7 -

7. Thermostat stuck shut. 7. Replace thermostat.

8. Bug screen or winter front being

used.

9. Viscous fan drive not operating

properly.

10. Cylinder head gasket leaking. 10. Check for leaking head gaskets

11. Heater core leaking. 11. Replace heater core.

12. cooling system hoses leaking. 12. Tighten clamps or Replace

1. None. System operating normaly.

2. Connect gauge.

3. Check gauge. Refer (Refer to 8 ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING)

COOLING - STANDARD PROCEDURE)

1. Temporary condition, repair not required. Notify customer of vehicle operation instructions located in Owners Manual.

2. Check gauge. (Refer to 8 ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING)

COOLING - STANDARD PROCEDURE) and refill (Refer to 7

- COOLING - STANDARD PROCEDURE)

5. Clean all debre away from A/C and radiator cooling fins.

COOLING - STANDARD PROCEDURE) refill with correct mixture (Refer to 7 - COOLING STANDARD PROCEDURE).

8. Remove bug screen or winter front.

9. Check viscous fan (Refer to 7 COOLING/ENGINE/FAN DRIVE VISCOUS CLUTCH - DIAGNOSIS AND TESTING)

(Refer to 7 - COOLING DIAGNOSIS AND TESTING).

hoses.

7 - 14 COOLING BR/BE

COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION

13. Brakes dragging. 13. Check brakes. (Refer to 5 BRAKES/HYDRAULIC/ MECHANICAL - DIAGNOSIS AND TESTING)

TEMPERATURE GAUGE READING INCONSISTENT ( ERRATIC, CYCLES OR FLUCTUATES)

RADIATOR CAP LEAKING STEAM AND /OR COOLANT INTO RESERVOIR BOTTLE. (TEMPERATURE GAUGE MAY READ HIGH)

1. Heavy duty cooling system,

extream cold ambient (outside) temperature or heater blower motor in high position.

2. Temperature gauge or gauge

sensor defective.

3. Temporary heavy usage or load. 3. None. Normal condition.

4. Air traped in cooling system. 4. Fill cooling system (Refer to 7 -

5. Water pump 5. Replace water pump.

6. Air leak on suction side of water

pump.

1. Radiator cap defective. 1. Replace radiator cap.

2. Radiator neck surface damaged. 2. Replace radiator.

1. None. System operating normaly.

2. Check gauge. (Refer to 8 ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING)

COOLING - STANDARD PROCEDURE).

6. Check for leak. (Refer to 7 COOLING - DIAGNOSIS AND TESTING)

HOSE OR HOSES COLLAPSE WHEN ENGINE IS COOLING.

NOISY FAN 1. Fan blade(s) loose, damaged. 1. Replace fan blade assembly.

INADEQUATE AIR CONDITIONER PERFORMANCE (COOLING SYSTEM SUSPECTED)

1. Vacuum created in cooling

system on engine cool-down is not being relieved through coolant reservior/overflow system.

2. Thermal viscous fan drive. 2. None. Normal condition.

3. Fan blades striking surrounding

objects.

4. Thermal viscous fan drive

bearing.

5. Obstructed air flow through

radiator.

1. Radiator and/or A/C condenser

air flow obstructed.

1. Replace radiator cap, check vent hose between radiator and reservoir bottle for blockage also check reservoir bottle vent for blockage.

3. Locate contact point and repair as necessary.

4. Replace viscous fan drive assembly.

5. Remove obstruction.

1. Remove obstruction and/or clean.

BR/BE COOLING 7 - 15

COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION

2. Thermal viscous fan drive not

working.

3. Air seals around radiator

damaged or missing.

INADEQUATE HEATER PERFORMANCE. GUAGE MAY OR MAY NOT READ LOW.

HEAT ODOR 1. Damaged or missing drive line

1. Heavy duty cooling system, and

cooler ambient temperatures.

2. Obstruction in heater hoses. 2. Remove hoses, remove

3. Water pump damaged. 3. Replace water pump.

heat shields.

2. Thermal viscous fan drive

damaged.

STANDARD PROCEDURE

2. Check fan drive. (Refer to 7 COOLING/ENGINE/FAN DRIVE VISCOUS CLUTCH - DIAGNOSIS AND TESTING)

3. Inspect air seals, repair or replace as necessary.

1. None. Normal condition.

obstruction.

1. Repair or replace damaged or missing heat shields.

2. Check thermal viscous fan drive. (Refer to 7 - COOLING/ENGINE/ FAN DRIVE VISCOUS CLUTCH DIAGNOSIS AND TESTING)

STANDARD PROCEDURE - DRAINING COOLING SYSTEM 5.9L/8.0L ENGINES

WARNING: DO NOT REMOVE CYLINDER BLOCK DRAIN PLUGS OR LOOSEN RADIATOR DRAINCOCK WITH SYSTEM HOT AND UNDER PRESSURE. SERIOUS BURNS FROM COOLANT CAN OCCUR.

DO NOT WASTE reusable coolant. If solution is

clean, drain coolant into a clean container for reuse.

(1) Remove radiator pressure cap. (2) Loosen radiator petcock. (3) Remove cylinder block drain plugs. Refer to

(Fig. 7).

STANDARD PROCEDURE—DRAINING COOLING SYSTEM 5.9L DIESEL ENGINE

WARNING: DO NOT REMOVE THE CYLINDER BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR DRAIN PLUG WITH SYSTEM HOT AND UNDER PRESSURE. SERIOUS BURNS FROM COOLANT CAN OCCUR.

DO NOT WASTE reusable coolant. If the solution is clean, drain the coolant into a clean container for reuse.

(1) Start the engine and place the heater control temperature selector in the Full-On position. Vacuum is needed to actuate the heater controls.

Fig. 7 Cylinder Block Drain Plug - 5.9L Engines

1 - BLOCK DRAIN PLUG

(2) Turn the ignition off.

(3) Do not remove radiator cap when draining coolant from reserve/overflow tank. Open radiator drain plug and when tank is empty, remove radiator cap. If the coolant reserve/overflow tank does not drain, (Refer to 7 - COOLING - DIAGNOSIS AND TESTING). The coolant need not be removed from tank unless the system is being refilled with fresh mixture.

(4) Remove radiator pressure cap.

7 - 16 COOLING BR/BE

COOLING (Continued)

STANDARD PROCEDURE - REFILLING COOLING SYSTEM 5.9L/8.0L ENGINES

WARNING: DO NOT REMOVE CYLINDER BLOCK DRAIN PLUGS OR LOOSEN RADIATOR DRAINCOCK WITH SYSTEM HOT AND UNDER PRESSURE. SERIOUS BURNS FROM COOLANT CAN OCCUR.

DO NOT WASTE reusable coolant. If solution is

clean, drain coolant into a clean container for reuse.

Clean cooling system prior to refilling. (Refer to 7 -

COOLING - STANDARD PROCEDURE).

(1) Install cylinder block drain plugs. Coat the

threads with Mopart Thread Sealant with Teflon.

(2) Close radiator petcock. (3) Fill cooling system with a 50/50 mixture of

water and antifreeze.

(4) Fill coolant reserve/overflow tank to FULL

mark on indicator stick.

(5) Start and operate engine until thermostat

opens (upper radiator hose warm to touch).

(6) If necessary, add a 50/50 water and antifreeze mixture to the coolant reserve/overflow tank. This is done to maintain coolant level between the FULL and ADD marks. The level in the reserve/overflow tank may drop below the ADD mark after three or four warm-up and cool-down cycles.

STANDARD PROCEDURE - ADDING ADDITIONAL COOLANT

The use of aluminum cylinder blocks, cylinder heads and water pumps requires special corrosion protection. Only Mopart Antifreeze/Coolant, 5 Year/100,000 Mile Formula (glycol base coolant with corrosion inhibitors called HOAT, for Hybrid Organic Additive Technology) is recommended. This coolant offers the best engine cooling without corrosion when mixed with 50% distilled water to obtain to obtain a freeze point of -37°C (-35°F). If it loses color or becomes contaminated, drain, flush, and replace with fresh properly mixed coolant solution.

CAUTION: Do not use coolant additives that are claimed to improve engine cooling.

STANDARD PROCEDURE—COOLANT LEVEL CHECK

NOTE: Do not remove radiator cap for routine coolant level inspections. The coolant level can be checked at coolant recovery bottle.

STANDARD PROCEDURE—REFILLING COOLING SYSTEM 5.9L DIESEL ENGINE

Clean cooling system prior to refilling (Refer to 7 -

COOLING - STANDARD PROCEDURE).

(1) Close radiator drain plug.

CAUTION: Due to the use of the one-way check valve, the engine must not be operating when refilling the cooling system.

NOTE: The diesel engine is equipped with a oneway check valve (jiggle pin). The check valve is used as a servicing feature and will vent air when the system is being filled. Water pressure (or flow) will hold the valve closed.

(2) Fill the cooling system with a 50/50 mixture of

water and antifreeze.

(3) Fill coolant reserve/overflow tank to the FULL

mark.

(4) Start and operate engine until thermostat

opens. Upper radiator hose should be warm to touch.

(5) If necessary, add 50/50 water and antifreeze mixture to the coolant reserve/overflow tank to maintain coolant level. This level should be between the ADD and FULL marks. The level in the reserve/overflow tank may drop below the ADD mark after three or four warm-up and cool-down cycles.

Fig. 8 COOLANT RESERVE/OVERFLOW TANK—ALL

EXCEPT 8.0L V-10 ENGINE

1 - T-SLOTS 2 - ALIGNMENT PIN 3 - FAN SHROUD 4 - COOLANT RESERVE/OVERFLOW TANK

BR/BE COOLING 7 - 17

COOLING (Continued)

The coolant reserve/overflow system provides a quick method for determining coolant level without removing radiator pressure cap. With engine not running, open the coolant recovery bottle cap and remove coolant level indicator dipstick to observe coolant level in coolant recovery bottle. The coolant level should be between ADD and FULL marks. If the coolant level is at or below the ADD mark, fill the recovery bottle with a 50/50 mixture of antifreeze and water ONE QUART AT A TIME. Repeat this procedure until the coolant level is at the FULL mark (Fig. 8).

STANDARD PROCEDURE - COOLING SYSTEM CLEANING/REVERSE FLUSHING

CLEANING

Drain cooling system and refill with water. Run engine with radiator cap installed until upper radiator hose is hot. Stop engine and drain water from system. If water is dirty, fill system with water, run engine and drain system. Repeat until water drains clean.

REVERSE FLUSHING

Reverse flushing of cooling system is the forcing of water through the cooling system. This is done using air pressure in the opposite direction of normal coolant flow. It is usually only necessary with very dirty systems with evidence of partial plugging.

REVERSE FLUSHING ENGINE

Drain cooling system. Remove thermostat housing and thermostat. Install thermostat housing. Disconnect radiator upper hose from radiator and attach flushing gun to hose. Disconnect radiator lower hose from water pump and attach a lead-away hose to water pump inlet fitting.

CAUTION: On vehicles equipped with a heater water control valve, be sure heater control valve is closed (heat off). This will prevent coolant flow with scale and other deposits from entering heater core.

Connect water supply hose and air supply hose to flushing gun. Allow engine to fill with water. When engine is filled, apply air in short blasts, allowing system to fill between air blasts. Continue until clean water flows through the lead away hose.

Remove lead away hose, flushing gun, water supply hose and air supply hose. Remove thermostat housing and install thermostat. Install thermostat housing with a replacement gasket. Refer to Thermostat Replacement. Connect radiator hoses. Refill cooling system with correct antifreeze/water mixture. Refer to Refilling the Cooling System.

CHEMICAL CLEANING

In some instances, use a radiator cleaner (Mopar Radiator Kleen or equivalent) before flushing. This will soften scale and other deposits and aid flushing operation.

REVERSE FLUSHING RADIATOR

Disconnect radiator hoses from radiator inlet and outlet. Attach a section of radiator hose to radiator bottom outlet fitting and insert flushing gun. Connect a water supply hose and air supply hose to flushing gun.

CAUTION: Internal radiator pressure must not exceed 138 kPa (20 psi) as damage to radiator may result.

Allow radiator to fill with water. When radiator is filled, apply air in short blasts. Allow radiator to refill between blasts. Continue this reverse flushing until clean water flows out through rear of radiator cooling tube passages. Have radiator cleaned more extensively by a radiator repair shop.

CAUTION: Follow manufacturers instructions when using these products.

STANDARD PROCEDURE - COOLANT SELECTION - ADDITIVES

CAUTION: Do not use coolant additives that are claimed to improve engine cooling.

7 - 18 COOLING BR/BE

COOLING (Continued)

SPECIFICATIONS

TORQUE

DESCRIPTION N·m Ft. In.

Lbs. Lbs

Belt Tensioner Pulley 5.9L Engine-Bolt 61 45 —

Belt Tensioner Pulley 8.0L Engine—

Bolt 88 65 — Belt Tensioner to Mounting

Bracket— Bolt 5.9L Engine 67 50 —

Belt Tensioner to Mounting

Bracket—

Bolt 8.0L Engine 41 30 — Block Heater—Screw Gas

Engines Block Heater—Hex Diesel

Engine Fan Shroud to Radiator

Mounting— Bolts 6 — 50

Heater Hose Fitting at Water Pump—(8.0L) 16 — 142

Idler Pulley Mounting—Bolts Gas Engines 61 45 —

Radiator Mounting—Bolts 11 — 95 Thermal Viscous Fan to

Hub—(Diesel) Thermostat Housing—Bolts

5.9L 23 — 200 Thermostat Housing—Bolts

8.0L Thermostat Housing—Bolts

Diesel Water Pump Mounting—Bolts

Gas Engines 40 30 —

Water Pump Mounting—Bolts

Diesel

2—17

43 32 —

57 42 —

25 — 220

24 — 212

SPECIAL TOOLS

COOLING

SPANNER WRENCH 6958

Adapter Pins 8346

Pliers 6094

Pressure Tester 7700–A

BR/BE ACCESSORY DRIVE 7 - 19

ACCESSORY DRIVE

TABLE OF CONTENTS

page page

BELT TENSIONERS - 5.9L

DESCRIPTION .........................19

OPERATION ...........................19

REMOVAL .............................19

INSTALLATION .........................20

BELT TENSIONERS - 8.0L

DESCRIPTION .........................20

OPERATION ...........................21

REMOVAL .............................21

INSTALLATION .........................22

BELT TENSIONERS - 5.9L DIESEL

DESCRIPTION .........................23

OPERATION ...........................23

REMOVAL .............................23

INSTALLATION .........................23

DRIVE BELTS - 5.9L

DIAGNOSIS AND TESTING - ACCESSORY

DRIVE BELT .........................24

REMOVAL .............................26

BELT TENSIONERS - 5.9L

DESCRIPTION

Correct drive belt tension is required to ensure optimum performance of the belt driven engine accessories. If specified tension is not maintained, belt slippage may cause; engine overheating, lack of power steering assist, loss of air conditioning capacity, reduced generator output rate, and greatly reduced belt life.

It is not necessary to adjust belt tension on the

5.9L engines. These engines are equipped with an automatic belt tensioner (Fig. 1). The tensioner maintains correct belt tension at all times. Due to use of this belt tensioner, do not attempt to use a belt tension gauge on 5.9L engines.

INSTALLATION .........................26

DRIVE BELTS - 8.0L

DIAGNOSIS AND TESTING—ACCESSORY

DRIVE BELT .........................27

REMOVAL .............................29

INSTALLATION .........................29

DRIVE BELTS - 5.9L DIESEL

DIAGNOSIS AND TESTING—ACCESSORY

DRIVE BELT .........................30

REMOVAL .............................32

INSTALLATION .........................32

VACUUM PUMP - 5.9L DIESEL

DESCRIPTION .........................33

OPERATION ...........................34

DIAGNOSIS AND TESTING—VACUUM PUMP

OUTPUT ............................34

REMOVAL .............................34

INSTALLATION .........................36

Fig. 1 Automatic Belt Tensioner - 5.9L Engines

1 - AUTOMATIC TENSIONER 2 - COIL AND BRACKET 3 - SCREW AND WASHER

OPERATION

The automatic belt tensioner maintains belt tension by using internal spring pressure, a pivoting arm and pulley to press against the drive belt.

REMOVAL

WARNING: BECAUSE OF HIGH SPRING PRESSURE, DO NOT ATTEMPT TO DISASSEMBLE AUTOMATIC TENSIONER. UNIT IS SERVICED AS AN ASSEMBLY (EXCEPT FOR PULLEY).

(1) Remove accessory drive belt. (Refer to 7 COOLING/ACCESSORY DRIVE/DRIVE BELTS REMOVAL).

(2) Disconnect wiring and secondary cable from ignition coil.

(3) Remove ignition coil from coil mounting bracket (two bolts). Do not remove coil mounting bracket from cylinder head.

7 - 20 ACCESSORY DRIVE BR/BE

BELT TENSIONERS - 5.9L (Continued)

(4) Remove tensioner assembly from mounting

bracket (one nut) (Fig. 2).

(4) Install coil to coil bracket. If nuts and bolts are used to secure coil to coil bracket, tighten to 11 N·m (100 in. lbs.) torque. If coil mounting bracket has been tapped for coil mounting bolts, tighten bolts to 5 N·m (50 in. lbs.) torque.

(5) Install drive belt. (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - INSTALLATION).

(6) Check belt indexing marks (Fig. 2).

BELT TENSIONERS - 8.0L

DESCRIPTION

CAUTION: Do not attempt to check belt tension with a belt tension gauge on vehicles equipped with an automatic belt tensioner.

Drive belts on 8.0L engines are equipped with a spring loaded automatic belt tensioner (Fig. 3) This belt tensioner will be used with all belt configurations, such as with or without power steering or air conditioning.

The tensioner is equipped with an indexing arrow (Fig. 4) on back of tensioner and an indexing mark on tensioner housing.

Fig. 2 Tensioner Indexing Marks and Mounting Nut

1 - TENSIONER ASSEMBLY 2 - TENSIONER MOUNTING NUT 3 - INDEXING ARROW 4 - INDEXING MARK

(5) Remove pulley bolt. Remove pulley from ten-

sioner.

INSTALLATION

(1) Install pulley and pulley bolt to tensioner.

Tighten bolt to 61 N·m (45 ft. lbs.) torque.

(2) Install tensioner assembly to mounting bracket. An indexing tab is located on back of tensioner. Align this tab to slot in mounting bracket. Tighten nut to 67 N·m (50 ft. lbs.) torque.

(3) Connect all wiring to ignition coil.

CAUTION: To prevent damage to coil case, coil mounting bolts must be torqued.

Fig. 3 Belt Tensioner—8.0L V-10 Engines

1 - PULLEY BOLT 2 - IDLER PULLEY 3 - TENSIONER PULLEY 4 - TENSIONER 5 - TENSIONER MOUNTING BOLT

BR/BE ACCESSORY DRIVE 7 - 21

BELT TENSIONERS - 8.0L (Continued)

• Belt incorrectly routed.

A used belt should be replaced if tensioner indexing arrow has moved to point-A (Fig. 5). Tensioner travel stops at point-A.

Fig. 4 Indexing Marks—8.0L Engines Typical

1 - TENSIONER ASSEMBLY 2 - TENSIONER MOUNTING NUT 3 - INDEXING ARROW 4 - INDEXING MARK

OPERATION

WARNING: THE AUTOMATIC BELT TENSIONER ASSEMBLY IS SPRING LOADED. DO NOT ATTEMPT TO DISASSEMBLE THE TENSIONER ASSEMBLY.

The automatic belt tensioner maintains correct belt tension using a coiled spring within the tensioner housing. The spring applies pressure to the tensioner arm pressing the arm into the belt, tensioning the belt.

If a new belt is being installed, the arrow must be within approximately 3 mm (1/8 in.) of indexing mark (point B-) (Fig. 5). Belt is considered new if it has been used 15 minutes or less. If this specification cannot be met, check for:

• The wrong belt being installed (incorrect length/

width)

• Worn bearings on an engine accessory (A/C compressor, power steering pump, water pump, idler pulley or generator)

• A pulley on an engine accessory being loose

• Misalignment of an engine accessory

Fig. 5 Indexing Marks—8.0L Engines Typical

1 - TENSIONER ASSEMBLY 2 - TENSIONER MOUNTING NUT 3 - INDEXING ARROW 4 - INDEXING MARK

REMOVAL

WARNING: BECAUSE OF HIGH SPRING PRESSURE, DO NOT ATTEMPT TO DISASSEMBLE AUTOMATIC TENSIONER. UNIT IS SERVICED AS AN ASSEMBLY (EXCEPT FOR PULLEY).

CAUTION: If the pulley is to be removed from the tensioner, its mounting bolt has left-hand threads.

(1) Remove accessory drive belt (Refer to 7 COOLING/ACCESSORY DRIVE/DRIVE BELTS REMOVAL).

(2) Remove tensioner mounting bolt (Fig. 6) and remove tensioner.

7 - 22 ACCESSORY DRIVE BR/BE

BELT TENSIONERS - 8.0L (Continued)

Fig. 7 Tensioner Dowel Pin

1 - BELT TENSIONER 2 - DOWEL PIN

Fig. 6 Belt Tensioner

1 - PULLEY BOLT 2 - IDLER PULLEY 3 - TENSIONER PULLEY 4 - TENSIONER 5 - TENSIONER MOUNTING BOLT

INSTALLATION

CAUTION: If the pulley is to be removed from the tensioner, its mounting bolt has left-hand threads.

(1) Install pulley and pulley bolt to tensioner.

Tighten bolt to 88 N·m (65 ft. lbs.) torque.

(2) Install tensioner assembly to mounting bracket. A dowel pin is located on back of tensioner (Fig. 7). Align this to dowel hole (Fig. 8) in tensioner mounting bracket. Tighten bolt to 41 N·m (30 ft. lbs.) torque.

(3) Install drive belt (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - INSTALLATION).

Fig. 8 Tensioner Dowel Hole

1 - DOWEL PIN HOLE 2 - TENSIONER MOUNTING BRACKET

BR/BE ACCESSORY DRIVE 7 - 23

BELT TENSIONERS - 5.9L DIESEL

DESCRIPTION

Drive belts on all engines are equipped with a spring loaded automatic belt tensioner (Fig. 9). This tensioner maintains constant belt tension at all times and requires no maintenance or adjustment.

CAUTION: Do not attempt to check belt tension with a belt tension gauge on vehicles equipped with an automatic belt tensioner.

• Worn bearings on an engine accessory (A/C compressor, power steering pump, water pump, idler pulley or generator)

• A pulley on an engine accessory being loose

• Misalignment of an engine accessory

• Belt incorrectly routed.

REMOVAL

WARNING: BECAUSE OF HIGH SPRING PRESSURE, DO NOT ATTEMPT TO DISASSEMBLE AUTOMATIC TENSIONER. UNIT IS SERVICED AS AN ASSEMBLY.

(1) Remove accessory drive belt (Refer to 7 COOLING/ACCESSORY DRIVE/DRIVE BELTS REMOVAL).

(2) Remove tensioner mounting bolt (Fig. 10) and remove tensioner.

Fig. 9 Belt

1 - WATER PUMP 2 - ACCESSORY DRIVE BELT 3 - AUTOMATIC BELT TENSIONER 4 - 3/89 SQUARE BOLT 5 - MOUNT. BOLT

OPERATION

WARNING: THE AUTOMATIC BELT TENSIONER ASSEMBLY IS SPRING LOADED. DO NOT ATTEMPT TO DISASSEMBLE THE TENSIONER ASSEMBLY.

If a new belt is being installed, the arrow must be within approximately 3 mm (1/8 in.) of indexing mark. Belt is considered new if it has been used 15 minutes or less. If this specification cannot be met, check for:

• The wrong belt being installed (incorrect length/

width)

Fig. 10 Automatic Belt Tensioner Diesel Engine—

Typical

1 - WATER PUMP 2 - ACCESSORY DRIVE BELT 3 - AUTOMATIC BELT TENSIONER 4 - 3/89 SQUARE BOLT 5 - MOUNT. BOLT

INSTALLATION

(1) Install tensioner assembly to mounting bracket. A dowel is located on back of tensioner. Align this dowel to hole in tensioner mounting bracket. Tighten bolt to 41 N·m (30 ft. lbs.) torque.

(2) Install drive belt (Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - INSTALLATION).

7 - 24 ACCESSORY DRIVE BR/BE

DRIVE BELTS - 5.9L

DIAGNOSIS AND TESTING - ACCESSORY DRIVE BELT

VISUAL DIAGNOSIS

When diagnosing serpentine accessory drive belts, small cracks that run across the ribbed surface of the belt from rib to rib (Fig. 11), are considered normal. These are not a reason to replace the belt. However, cracks running along a rib (not across) are not normal. Any belt with cracks running along a rib must be replaced (Fig. 11). Also replace the belt if it has excessive wear, frayed cords or severe glazing.

Refer to ACCESSORY DRIVE BELT DIAGNOSIS CHART for further belt diagnosis.

NOISE DIAGNOSIS

Noises generated by the accessory drive belt are most noticeable at idle. Before replacing a belt to resolve a noise condition, inspect all of the accessory drive pulleys for alignment, glazing, or excessive end play.

1 - NORMAL CRACKS BELT OK 2 - NOT NORMAL CRACKS REPLACE BELT

Fig. 11 Belt Wear Patterns

ACCESSORY DRIVE BELT DIAGNOSIS CHART

CONDITION POSSIBLE CAUSES CORRECTION

RIB CHUNKING (One or more ribs has separated from belt body)

RIB OR BELT WEAR 1. Pulley misaligned 1. Align pulley(s)

BELT SLIPS 1. Belt slipping because of insufficient

1. Foreign objects imbedded in pulley grooves.

2. Installation damage 2. Replace belt

2. Abrasive environment 2. Clean pulley(s). Replace belt if

3. Rusted pulley(s) 3. Clean rust from pulley(s)

4. Sharp or jagged pulley groove tips 4. Replace pulley. Inspect belt.

5. Belt rubber deteriorated 5. Replace belt

tension

2. Belt or pulley exposed to substance that has reduced friction (belt dressing, oil, ethylene glycol)

3. Driven component bearing failure (seizure)

4. Belt glazed or hardened from heat and excessive slippage

1. Remove foreign objects from pulley grooves. Replace belt.

necessary

1. Inspect/Replace tensioner if necessary

2. Replace belt and clean pulleys

3. Replace faulty component or bearing

4. Replace belt.

BR/BE ACCESSORY DRIVE 7 - 25

DRIVE BELTS - 5.9L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION

LONGITUDAL BELT CRACKING

9GROOVE JUMPING9 (Belt does not maintain correct position on pulley)

BELT BROKEN (Note: Identify and correct problem before new belt is installed)

1. Belt has mistracked from pulley groove

2. Pulley groove tip has worn away rubber to tensile member

1. Incorrect belt tension 1. Inspect/Replace tensioner if

2. Pulley(s) not within design tolerance

3. Foreign object(s) in grooves 3. Remove foreign objects from

4. Pulley misalignment 4. Align component

5. Belt cordline is broken 5. Replace belt

1. Incorrect belt tension 1. Replace Inspect/Replace tensioner

2. Tensile member damaged during belt installation

3. Severe misalignment 3. Align pulley(s)

4. Bracket, pulley, or bearing failure 4. Replace defective component and

1. Replace belt

2. Replace belt

necessary

2. Replace pulley(s)

grooves

if necessary

2. Replace belt

belt

NOISE (Objectionable squeal, squeak, or rumble is heard or felt while drive belt is in operation)

TENSION SHEETING FABRIC FAILURE (Woven fabric on outside, circumference of belt has cracked or separated from body of belt)

CORD EDGE FAILURE (Tensile member exposed at edges of belt or separated from belt body)

1. Incorrect belt tension 1. Inspect/Replace tensioner if necessary

2. Bearing noise 2. Locate and repair

3. Belt misalignment 3. Align belt/pulley(s)

4. Belt to pulley mismatch 4. Install correct belt

5. Driven component induced

vibration

1. Tension sheeting contacting

stationary object

2. Excessive heat causing woven

fabric to age

3. Tension sheeting splice has

fractured

1. Incorrect belt tension 1. Inspect/Replace tensioner if

2. Belt contacting stationary object 2. Replace belt

3. Pulley(s) out of tolerance 3. Replace pulley

4. Insufficient adhesion between

tensile member and rubber matrix

5. Locate defective driven component and repair

1. Correct rubbing condition

2. Replace belt

3. Replace belt

necessary

4. Replace belt

7 - 26 ACCESSORY DRIVE BR/BE

DRIVE BELTS - 5.9L (Continued)

REMOVAL

NOTE: The belt routing schematics are published from the latest information available at the time of publication. If anything differs between these schematics and the Belt Routing Label, use the schematics on Belt Routing Label. This label is located in the engine compartment.

CAUTION: Do not attempt to check belt tension with a belt tension gauge on vehicles equipped with an automatic belt tensioner. Refer to Automatic Belt Tensioner in this group.

Drive belts on these engines are equipped with a spring loaded automatic belt tensioner (Fig. 12). This belt tensioner will be used on all belt configurations, such as with or without power steering or air conditioning. For more information, (Refer to 7 - COOLING/ACCESSORY DRIVE/BELT TENSIONERS DESCRIPTION).

(1) Attach a socket/wrench to pulley mounting bolt

of automatic tensioner (Fig. 12).

(2) Rotate tensioner assembly clockwise (as viewed

from front) until tension has been relieved from belt.

(3) Remove belt from idler pulley first. (4) Remove belt from vehicle.

INSTALLATION

CAUTION: When installing the accessory drive belt, the belt must be routed correctly. If not, engine may overheat due to water pump rotating in wrong direction. Refer to (Fig. 13) (Fig. 14) for correct engine belt routing. The correct belt with correct length must be used.

(1) Position drive belt over all pulleys except idler pulley. This pulley is located between generator and A/C compressor.

(2) Attach a socket/wrench to pulley mounting bolt of automatic tensioner (Fig. 12).

(3) Rotate socket/wrench clockwise. Place belt over idler pulley. Let tensioner rotate back into place. Remove wrench. Be sure belt is properly seated on all pulleys.

(4) Check belt indexing marks.

Fig. 12 Belt Tensioner - 5.9L Gas Engines

1 - IDLER PULLEY 2 - TENSIONER 3 - FAN BLADE

Fig. 13 Belt Routing - 5.9L Engines with A/C

1 - GENERATOR PULLEY 2 - A/C PULLEY 3 - POWER STEERING PULLEY 4 - CRANKSHAFT PULLEY 5 - WATER PUMP PULLEY 6 - TENSIONER PULLEY 7 - IDLER PULLEY

BR/BE ACCESSORY DRIVE 7 - 27

DRIVE BELTS - 5.9L (Continued)

be replaced (Fig. 15). Also replace the belt if it has excessive wear, frayed cords or severe glazing.

Refer to ACCESSORY DRIVE BELT DIAGNOSIS CHART for further belt diagnosis.

Fig. 14 Belt Routing - 5.9L Engines Without A/C

1 - GENERATOR PULLEY 2 - IDLER PULLEY 3 - POWER STEERING PULLEY 4 - CRANKSHAFT PULLEY 5 - WATER PUMP PULLEY 6 - TENSIONER PULLEY

DRIVE BELTS - 8.0L

DIAGNOSIS AND TESTING—ACCESSORY DRIVE BELT

VISUAL DIAGNOSIS

When diagnosing serpentine accessory drive belts, small cracks that run across the ribbed surface of the belt from rib to rib (Fig. 15), are considered normal. These are not a reason to replace the belt. However, cracks running along a rib (not across) are not normal. Any belt with cracks running along a rib must

Fig. 15 Belt Wear Patterns

1 - NORMAL CRACKS BELT OK 2 - NOT NORMAL CRACKS REPLACE BELT

NOISE DIAGNOSIS

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