Bendix Commercial Vehicle Systems 720CC User Manual

BENDIX® 720CC TWIN CYLINDER COMPRESSOR FOR INTERNATIONAL MAXXFORCE

™

BIG BORE ENGINES

SD-01-3131

Cylinder

Head

Cooling

Plate

Valve Plate

Assembly Crankcase

Mounting

Face

Locating

Pins

FIGURE 1 - BENDIX® 720CC TWIN CYLINDER COMPRESSOR

PRODUCT

This Bendix® 720cc twin cylinder compressor is a “discharge line unloader” (DLU)-style compressor. The compressor pumps continuously, unlike some compressor designs which use an "unloader" mechanism in the compressor head to switch from a pumping mode to a non-pumping mode. With a DLU-style compressor, the control of air delivery to the vehicle’s air system is managed by using a separate discharge line unloader valve mounted in parallel with a turbo cut-off-style of air dryer (see Figure 6).

DESCRIPTION

Safety

Valve

Right Side

View

Rear

Flange

The cylinder head assembly is made up of an aluminum cylinder head, an aluminum cooling plate, and a cast iron valve plate assembly. It uses two sealing gaskets. The cylinder head contains air and water ports. A cooling plate is located between the cylinder head and valve plate assemblies and assists in cooling.

The valve plate assembly consists of brazed cast iron plates which have valve openings and passages for air and engine coolant to ﬂ ow into, and out of, the cylinder head and crankcase water jacket. The compressor discharge valves are part of the valve plate assembly. The inlet reed valve/

The function of the air compressor is to provide and maintain air, under pressure, to operate devices in air brake systems. The Bendix

720cc compressor is a twin cylinder reciprocating compressor with a rated displacement of 31.6 cubic feet per minute at 1250 RPM.

The compressor consists of an integral water-cooled cylinder head assembly and water-cooled crankcase.

720cc COMPRESSOR

BENDIX

BENDIX PRODUCT - ASSY IN FRANCE

FIGURE 2 - NAMEPLATES

P/N

MAXXFORCE™ is a trademark of International Engine Intellectual Property Company, LLC.

NAV

P/N

Bendix Part Number . . . . . . A

Customer Part Number. . . . . B

Compressor Serial Number . . C

Safety

Valve

Cylinder

Head

Compressor to

engine block

mounting face

Oil drain locations

Cooling

Plate

Valve Plate

Assembly

Nameplate

Crankcase

FIGURE 3 - BENDIX® 720CC TWIN CYLINDER COMPRESSOR

Connecting

Rod

Crankshaft

Piston

Mounting

Face

Drive Gear

gasket is installed between the valve plate assembly and the top of the crankcase.

The cast iron crankcase has a water jacket to assist in the cooling of the cylinder bore. The crankcase has an open side with a machined face and locating pins. This open face is bolted directly to the side of the engine block. Refer to

Figure 3.

The compressor gear engages the engine drive gear. In addition, the crankcase houses the piston assembly, connecting rod, crankshaft, and related bearings. O-rings are located in the countersunk holes (one each side) on the crankcase deck to prevent coolant leakage between the crankcase and valve plate coolant passage.

The Bendix

720cc compressor is equipped with a safety valve to protect the compressor head in the event of, for example, a discharge line blockage downstream of the compressor. Excessive air pressure will cause the safety valve to unseat, release air pressure and give an audible alert to the operator. The safety valve is installed in the cylinder head safety valve port, directly connected to the cylinder head discharge port.

A nameplate is attached to a ﬂ at cast face on the side of the crankcase. It is stamped with information identifying the compressor model, customer piece number, compressor assembly part number and serial number. See Figure 2.

UNL

Air

Discharge

Port

Air Inlet

Port

Discharge

Valve

Closed

Air

Discharge

Port

Air Inlet

Port

Discharge

Valve Open

Cooling

Plate Valve

Plate

Inlet Valve Open

Piston Moving Down

FIGURE 4 - OPERATION - INTAKE

OPERATION

The compressor is driven by the vehicle's engine, and functions continuously while the engine is in operation. Actual compression of air is controlled by a downstream component – like a discharge line unloader valve or an air dryer without turbo cut-off valve – operating in conjunction with a governor.

AIR INTAKE (LOADED)

Just as the piston begins the down stroke, (a position known as top dead center, or TDC), the vacuum created in the cylinder bore above the piston causes the inlet reed valve to ﬂ ex open. Atmospheric air ﬂ ows through the open inlet valve and ﬁ lls the cylinder bore above the piston. See Figure 4.

Cooling

Plate

Valve

Plate

Inlet

Valve

Closed

Piston Moving Up

FIGURE 5 - OPERATION - COMPRESSION

AIR COMPRESSION (LOADED)

When the piston reaches the bottom of the stroke, (a position known as bottom dead center, or BDC), the inlet reed valve closes. Air above the piston is trapped by the closed inlet reed valve and is compressed as the piston moves upwards. When air in the cylinder bore reaches a pressure greater than that of the system pressure, the discharge reed valves open and allow air to ﬂ ow into the discharge line and air brake system. See Figure 5.

DLU Valve

Governor

FIGURE 6 - TYPICAL BENDIX® 720CC (DLU) TWIN CYLINDER COMPRESSOR AIR CHARGING SYSTEM

Compressor

Air Dryer

Front Service

Reservoir

Rear Service

Reservoir

Inlet Port

Discharge Port

Coolant Port

(In or Out)

Head

Bolt (8)

Coolant Port

(In or Out)

Oil

Supply

FIGURE 7 - BENDIX® 720CC TWIN CYLINDER COMPRESSOR PORT IDENTIFICATION

NON-COMPRESSION OF AIR (UNLOADED) COMPRESSOR AND AIR DRYER SYSTEM

(REFER TO FIGURE 6)

Air delivery to the vehicle’s air system is controlled either by the governor and the air dryer, or with a separate discharge line unloader valve. The governor is plumbed to the component (i.e. air dryer or DLU valve) in order to control when the air delivered to the vehicles air system.

When air pressure in the supply reservoir reaches the cutout setting of the governor, the governor delivers system air to the discharge line unloader style (DLU) air dryer’s control port. This allows the discharge air from the compressor to ﬂ ow out the exhaust port of the air dryer.

Note: The Bendix line unloader-style unit. This means that the compressor functions in a continuous pumping mode; regardless whether the brake system requires air. It requires a downstream device (e.g. turbo cut-off-style air dryer and discharge line unloader valve) to unload the system when air requirements have been met as described in the previous paragraph.

720cc compressor is a discharge

Safety

Valve Port

CYLINDER HEAD PORT IDENTIFICATION

The cylinder head connection ports are identiﬁ ed with “cast in” numerals as follows:

AIR IN . . . . . . . . . . . . . 0

Compressed AIR OUT. . . . . 2

Coolant IN . . . . . . . . . . . 9

Coolant Out . . . . . . . . . . 9

LUBRICATION

The vehicle's engine provides a continuous supply of oil to the compressor. Oil is routed from the engine to the compressor's oil inlet. Note: There is no external oil supply line; the oil delivery is located at the engine to compressor mounting face. (See Figure 7.) This pressurized oil ﬂ ows to the precision front sleeve main bearing, and via an oil passage in the crankshaft routes pressurized oil to the connecting rod bearings and the rear journal associated with the end cover. Spray lubrication of the cylinder bore and connecting rod wrist pin bushing is obtained as oil is forced out around the crankshaft journals by engine oil pressure. Oil then falls to the bottom of the compressor crankcase and is returned to the engine through the opening at the compressor mounting ﬂ ange.

COOLING

The Bendix by air ﬂ owing through the engine compartment as it passes the compressor's cast-in cooling ﬁ ns, and by the ﬂ ow of engine coolant through the cylinder head assembly and the water jacket around the cylinder bore of the crankcase. Coolant supplied by the engine cooling system passes

720cc twin cylinder compressor is cooled both

through connecting lines into the cylinder head, cooling plate, valve plate assembly, and into the crankcase water jacket. It returns through the same components, out of the coolant outlet port of the cylinder head, and returns to the engine. Figure 7 illustrates the approved coolant ﬂ ow connections. Proper cooling is important in minimizing discharge air temperatures – see the tabulated technical data on page 13 of this manual for speciﬁ c requirements.

AIR INDUCTION

The Bendix® 720cc twin cylinder compressor is only permitted to be naturally aspirated – use of an engine turbocharger as an air source is not allowed.

PREVENTATIVE MAINTENANCE

Regularly scheduled maintenance is the single most important factor in maintaining the air brake charging system. Refer to Table A: Maintenance Schedule and Usage Guidelines in the troubleshooting section (page A-3) for a guide to various considerations that must be given to maintenance of the compressor and other related charging system components.

Important Note: Review the Bendix performing any intrusive maintenance procedures. An extended warranty may be voided if intrusive maintenance is performed during this period.

EVERY 6 MONTHS, 1800 OPERATING HOURS OR AFTER EACH 50,000 MILES, WHICHEVER OCCURS FIRST, PERFORM THE FOLLOWING INSPECTIONS AND TESTS.

AIR INDUCTION INSPECTION

A supply of clean air is one of the single most important factors in compressor preventive maintenance. Since the air supply for the 720cc twin cylinder compressor and engine is the engine air cleaner, periodic maintenance of the engine air ﬁ lter is necessary.

Inspect the compressor air induction system each time engine air cleaner maintenance is performed.

1. Inspect the intake hose adapters for physical damage. Make certain to check the adapters at both ends of the intake hose or tubing.

2. Inspect the intake hose clamps and tighten them if needed.

3. Inspect the intake hose or line for signs of drying, cracking, chaﬁ ng and ruptures and replace if necessary.

4. Inspect the compressor ’s cast inlet tube for physical damage.

COMPRESSOR COOLING INSPECTION

Inspect the compressor discharge port, inlet cavity and discharge line for evidence of restrictions and carbon buildup. If more than 1/16" of carbon is found, thoroughly clean or replace the affected parts. In some case, carbon buildup indicates inadequate cooling. Closely inspect the compressor cooling system. Check all compressor coolant lines for kinks and restrictions to ﬂ ow. Minimum coolant line size is 3/8" I.D. Check coolant lines for internal clogging from rust scale. If coolant lines appear suspicious, check the coolant ﬂ ow and compare to the tabulated technical data present in the back of this manual.

Warranty Policy before

LUBRICATION INSPECTION

The compressor utilizes an internal oil feed design. Check the exterior of the compressor (i.e. around the mounting face) for the presence of oil seepage and refer to the troubleshooting section for appropriate tests and corrective action. Refer to the tabulated technical data in the back of this manual for oil pressure minimum values.

OIL PASSING INSPECTION

All reciprocating compressors pass a minimal amount of oil. Air dyers will remove the majority of oil before it can enter the air brake system. For particularly oil sensitive systems, the Bendix with a Bendix

PuraGuard® system can be used in conjunction

air dryer.

If compressor oil passing is suspected, refer to the troubleshooting section (starting on page A-1) for the symptoms and corrective action to be taken. In addition, Bendix has developed the “Bendix Air System Inspection

Cup”,or Bendix

BASIC™ kit, to help substantiate suspected excessive oil passing. The steps to be followed when using the BASIC

™

kit are presented in APPENDIX B.

COMPRESSOR DRIVE INSPECTION

Check for noisy compressor operation, which could indicate excessive drive component wear. Adjust and/or replace as necessary. Check all compressor mounting bolts and retighten evenly if necessary. Check for leakage. Repair or replace parts as necessary.

CHARGING SYSTEM UNLOADING & GOVERNOR TEST

Note: The Bendix® 720cc (DLU)-style twin cylinder

compressor does not contain components to unload the compressor. Therefore, the compressor pumps continuously. In most systems that utilize an air dryer, the governor and DLU-style air dryer are used to unload the system (e.g. air is not being delivered to the brake system reservoirs). When system unloading occurs, air from the compressor will typically ﬂ ow out the exhaust port of the air dryer. Refer to Figure 6.

Test and inspect the unloading system (i.e. air dryer and governor) for proper operation and pressure settings.

1. Make certain the unloader system lines (illustrated in

Figure 6) are connected and leak free.

2. Cycle the charging system between the loaded and

unloaded mode several times. This can be achieved by applying the brakes to bleed down the system pressure. Make certain that the governor cuts-in (charging system resumes compressing air) at a minimum of 105 psi. Governor cut-out (charging system stops delivering air to the brake system reservoirs) should be approximately 15 - 20 psi greater than cut-in pressure. Adjust or replace the governor as required.

3. Note that the charging system cycles to the loaded and unloaded conditions promptly. If prompt action is not noted, repair or replace the governor and/or repair the air dryer purge valve assembly.

IMPORTANT NOTE

Replacement air governors must have a minimum cut-in pressure of 100 psi. The cut-in pressure is the lowest system pressure registered in the gauges before the compressor resumes compressing air.

SERVICE TESTS

GENERAL

The compressor operating and leakage tests listed below need not be performed on a regular basis. These tests should be performed when it is suspected that leakage is substantially affecting compressor buildup performance, or when it is suspected that the charging system is “cycling” between the loaded (pumping) and unloaded (charging system stops delivering air to the brake system reservoirs) modes due to unloader system leakage.

Guide for Air Brake Compressors, starting on page A-1 of this document, to assist investigation of the cause(s).

Note: When comparing build-up times, be sure to make an allowance for any air system modiﬁ cations which would cause longer times, such as adding air components or reservoirs. Always check for air system leakage.

LEAKAGE TESTS

See the standard Air Brake System and Accessory Leakage test on Page A-14, Test 2.

Note: Leakage in the air supply system (components before the supply reservoir - such as the governor, air dryer , reservoir drain cocks, safety valve, and check valves) will not be registered on the vehicle dash gauges and must be tested separately. Refer to the various maintenance manuals for individual component leakage tests and the Bendix “Test and Checklist” published in the Brake System Handbook (BW5057) and on the back of the

Bendix

Card (BW1396).

Dual Circuit Brake System Troubleshooting

Bendix

Air

IN SERVICE OPERATING TESTS

Compressor Performance: Build-up Test

This test is performed with the vehicle parked and the engine operating at maximum recommended governed speed. Fully charge the air system to governor cut-out (air dryer purges). Pump the service brake pedal to lower the system air pressure below 80 psi using the dash gauges. As the air pressure builds back up, measure the time from when the dash gauge passes 85 psi to the time it passes 100 psi. The time should not exceed 40 seconds. If the vehicle exceeds 40 seconds, test for (and ﬁ x) any air leaks and then re- test the compressor performance. If the vehicle does not pass the test the second time, use the Advanced Troubleshooting Guide for Air Brake Compressors, starting on page A-1 of this document, to assist your investigation of the cause(s).

Note: All new vehicles are certiﬁ ed using the FMVSS 121 test (paragraph S5.1.1) by the vehicle manufacturer, however the above test is a useful guide for in-service vehicles.

Optional Comparative Performance Check

It may be useful to also conduct the above test with the engine running at high idle (instead of maximum governed speed), and record the time required to raise the system pressure a selected range (for example, from 90 to 120 psi, or from 100 to 120 psi, etc.) in the vehicle’s maintenance ﬁ les. Subsequent build-up times throughout the vehicle’s service life can then be compared to the ﬁ rst one recorded. (Note: the 40 second guide in the test above does not apply to this build-up time.) If the performance degrades signiﬁ cantly over time, use the Advanced Troubleshooting

CYLINDER HEAD

Check the cylinder head gaskets for air leakage.

1. With the engine running, lower the air system pressure to 60 psi and apply a soap solution around the cylinder head. Check the gaskets between the cylinder head and the valve plate assembly , as well as the inlet reed valve/gasket between the valve plate assembly and crankcase for air leakage.

2. No leakage is permitted. If leakage is detected, replace the compressor or repair the cylinder head using the maintenance kit available from an authorized Bendix parts outlet.

INLET & DISCHARGE VALVES

In order to test the inlet and discharge valves, it is necessary to have shop air pressure and an assortment of ﬁ ttings. A soap solution is also required.

1. With the engine shut off, drain ALL air pressure from the vehicle.

2. Disconnect the inlet and discharge lines.

3. Apply 120-130 psi shop air pressure to the discharge port and then apply and release air pressure to the inlet port. Soap the inlet port and note that leakage at the inlet port does not exceed 200 sccm.

If excessive leakage is noted in Test 3, replace or repair the compressor using genuine Bendix replacements or maintenance kits available from any authorized Bendix parts outlet.

While it is possible to test for inlet and discharge leakage, it may not be practical to do so. Inlet and discharge valve

leakage can generally be detected by longer compressor build-up and recovery times. Compare current compressor build-up times with the last several recorded times. Make certain to test for air system leakage, as described under “InService Operating Tests”, before making a determination that performance has been lost.

COMPRESSOR REMOVAL & DISASSEMBLY

GENERAL

The following disassembly and assembly procedure is presented for reference purposes and pre-supposes that a rebuild or repair of the compressor is being undertaken. Several maintenance kits are available and the instructions provided with these parts and kits should be followed in lieu of the instructions presented here.

MAINTENANCE KITS & SERVICE PARTS

BENDIX

Compressor Seal Kit (Major) . . . . . . . . . . .K026808

Compressor Seal Kit (Minor) . . . . . . . . . . .K051352

Discharge Safety Valve Kit . . . . . . . . . . . .K026809

Compressor to Engine Supplied by the

Mounting Face Sealant . . . . . . . Engine Manufacturer

720CC TWIN CYLINDER COMPRESSOR

GENERAL SAFETY GUIDELINES WARNING! PLEASE READ AND FOLLOW

THESE INSTRUCTIONS TO AVOID PERSONAL INJURY OR DEATH:

When working on or around a vehicle, the following general precautions should be observed at all times.

1. Park the vehicle on a level surface, apply the parking brakes, and always block the wheels. Always wear safety glasses.

2. Stop the engine and remove ignition key when working under or around the vehicle. When working in the engine compartment, the engine should be shut off and the ignition key should be removed. Where circumstances require that the engine be in operation, EXTREME CAUTION should be used to prevent personal injury resulting from contact with moving, rotating, leaking, heated or electrically charged components.

3. Do not attempt to install, remove, disassemble or assemble a component until you have read and thoroughly understand the recommended procedures. Use only the proper tools and observe all precautions pertaining to use of those tools.

4. If the work is being performed on the vehicle’s air brake system, or any auxiliary pressurized air systems, make certain to drain the air pressure from all reservoirs before beginning ANY work on the vehicle. If the vehicle is

equipped with a Bendix

AD-IS® air dryer system or a dryer reservoir module, be sure to drain the purge reservoir.

5. Following the vehicle manufacturer’s recommended procedures, deactivate the electrical system in a manner that safely removes all electrical power from the vehicle.

6. Never exceed manufacturer’s recommended pressures.

7. Never connect or disconnect a hose or line containing pressure; it may whip. Never remove a component or plug unless you are certain all system pressure has been depleted.

8. Use only genuine Bendix

brand replacement parts, components and kits. Replacement hardware, tubing, hose, ﬁ ttings, etc. must be of equivalent size, type and strength as original equipment and be designed speciﬁ cally for such applications and systems.

9. Components with stripped threads or damaged parts should be replaced rather than repaired. Do not attempt repairs requiring machining or welding unless specifically stated and approved by the vehicle and component manufacturer.

10. Prior to returning the vehicle to service, make certain all components and systems are restored to their proper operating condition.

1 1. For vehicles with Automatic Traction Control (ATC),

the ATC function must be disabled (ATC indicator lamp should be ON) prior to performing any vehicle maintenance where one or more wheels on a drive axle are lifted off the ground and moving.

REMOVAL

In many instances it may not be necessary to remove the compressor from the vehicle when installing the various maintenance kits and service parts. The maintenance technician must assess the installation and determine the correct course of action. These instructions are general and are intended to be a guide. In some cases additional preparations and precautions are necessary. In all cases follow the instructions contained in the vehicle maintenance manual in lieu of the instructions, precautions and procedures presented in this manual.

1. Block the wheels of the vehicle and drain the air pressure from all the reservoirs in the system.

2. Drain the engine cooling system and the cylinder head of the compressor. Identify and disconnect all air, water and oil lines leading to the compressor.

3. Remove as much road dirt and grease from the exterior of the compressor as possible.

Cylinder Head

Crankcase

Compressor

Drive Gear

Cooling

Plate

Valve Plate

Assembly

Side Cover

Crankcase

Alignment Pins

(x2) - one at

each end

Cap

Screws

(x2)

End Cover

Crankcase Side

Cover Cap

Screws (x6)

Safety Valve Kit Pc. No. K026809 consists of the following:

Item Qty. Description

1 1 Sealing Ring 2 1 ST-4

™

Safety Valve

Compressor Seal Kit (Major) Pc. No. K026808 consists of the following:

Item Qty. Description

3 8 Cap Screws (long) 4 2 Cap Screws (short) 5 1 Head Gasket

Compressor Seal Kit (Minor) Pc. No. K051352 consists of the following:

Item Qty. Description

9 1 Cover

10 1 End Cover O-Ring

FIGURE 8 – BENDIX® 720CC TWIN CYLINDER COMPRESSOR EXPLODED VIEW

6 1 Cooling Plate Gasket 7 1 Inlet Reed Valve/Gasket 8 2 Crankcase O-ring

9 1 Cover 10 1 End Cover O-Ring 11 1 Side Cover Gasket

4. Remove the discharge ﬁ tting, if applicable, and note their position on the compressor to aid in reassembly.

5. Remove any supporting bracketing attached to the compressor and note their positions on the compressor to aid in reassembly.

6. Remove the six (6) mounting bolts that retain the compressor to the side of the engine block. Note the position of the six mounting bolts. Two of the six bolts are shorter and must be installed in their original locations. Remove the compressor from the vehicle.

7. Inspect drive gear and associated drive parts for visible wear or damage. If the compressor drive gear is worn or damaged, the compressor must be replaced. Refer the Engine Manufacturers service manual to address the associated engine drive parts.

8. If the compressor is being replaced stop here and proceed to “Installing the Compressor” at the end of the assembly procedure. (Note: Replacement compressors come with the drive gear pre-assembled on the compressor.)

M10x1.5

Cap

Screws

(Larger)

M8x1.25

Cap

Screws

(Smaller)

FIGURE 9 - REAR END COVER ATTACHMENT BOLTS

PREPARATION FOR DISASSEMBLY

Place a clean rag over the openings that expose the gear and crankshaft / connecting rod assembly . Refer to Figure 3. No contamination is permitted in these areas.

Remove the balance of road dirt and grease from the exterior of the compressor with a cleaning solvent. If the rear end cover is being removed from the compressor, mark it, along with the two cap screws, in relation to the crankcase. It is also recommended to mark the relationship of the cylinder head, cooling plate, valve plate assembly, and crankcase.

A convenient method to indicate the above relationships is to use a metal scribe to mark the parts with numbers or lines. Do not use marking methods, such as chalk, that can be wiped off or obliterated during rebuilding.

Prior to disassembly make certain that the appropriate kits are available. Refer to Figure 8 during the entire disassembly and assembly procedure. The serviceable items are identiﬁ ed by "Item" numbers 1 through 11 . These items are also referenced in the following procedures and are denoted by the numbers in parenthesis.

3. Gently tap the cylinder head, cooling plate and valve plate assembly with a soft mallet to break the gasket seal between the valve plate assembly and the crankcase. Lift the cylinder head with cooling plate and valve plate assembly off the crankcase.

4. Remove the metal inlet reed valve gasket(7).

5. Remove the two crankcase o-rings (8) from the deck (top) of the crankcase. The o-rings are located in countersunk holes, one on each side of the cylinder bores.

6. Gently tap the removed cylinder head, cooling plate and valve plate assembly with a soft mallet to break the gasket seals. Then separate the cylinder head from the cooling plate and valve plate assembly and remove and discard the two head gaskets (5) and (6).

CYLINDER HEAD, COOLING PLATE & VALVE PLA TE ASSEMBLY

1. Remove the sealing ring (2) and discharge safety valve (1) from the compressor cylinder head.

2. Remove the two short hex head screws (4) and eight long hex head screws (3) from the compressor cylinder head.

FIGURE 10 - FRONT COVER

CRANKCASE FRONT COVER

1. Remove the cover (9) from the front of the crankcase. Use a sharp ﬂ at head screw driver or a scraper. Place the edge under the lip along the outside diameter of the cover. Pry the cover from the cast surface until the cover can be removed. Refer to Figure 10.

CRANKCASE SIDE COVER

1. Remove the six cap screws that secure the crankcase side cover to the crankcase.

2. Gently tap the crankcase side cover with a soft mallet to break the gasket seal between the crankcase side cover and the crankcase. Remove the crankcase side

cover and the gasket (11).

REAR END COVER

1. Note: There are two cap screws used to retain the end cover to the crankcase. There a two longer cap screws (not shown in Figure 9) that are used to retain the auxiliary drive unit (i.e. hydraulic pump) via the end cover and torqued into the crankcase. If the auxiliary drive unit has already been removed, these two cap screws are no longer present on the end cover. Refer to Figure 8 to see location of the cap screws in the end cover.

2. Remove the two end cover cap screws that secure the rear end cover to the crankcase.

3. Remove the rear end cover from the crankcase. Remove and discard the o-ring (10) from the end cover.

CLEANING OF PARTS

GENERAL

All parts should be cleaned in a good commercial grade of solvent and dried prior to inspection.

CRANKCASE

1. Carefully remove all sealant gasket material adhering to the machined face of the crankcase. See Figure

3. Make certain not to scratch or mar the mounting surface. Note: Keep the crankcase opening covered to prevent any of the sealant material from entering. Repeat this process on the engine mounting face as well. Follow the instructions contained in the vehicle maintenance manual in lieu of the instructions and procedures presented in this manual.

2. Carefully remove all gasket material adhering to the deck (top) of the crankcase. Remove any carbon deposits from the deck of the crankcase. Make certain not to scratch or mar the gasket surfaces.

CYLINDER HEAD, COOLING PLATE & VALVE PLA TE ASSEMBLY

1. Carefully remove all gasket material adhering to the cylinder head, cooling plate and valve plate assembly . Make certain not to scratch or mar the gasket surfaces. Pay particular attention to the gasket surfaces of the cylinder head and cooling plate.

2. Remove carbon deposits from the discharge and inlet cavities of the cylinder head, cooling plate and valve plate assembly. They must be open and clear in the components. Make certain not to damage the parts.

3. Remove rust and scale from the cooling cavities and passages in the cylinder head, cooling plate and valve plate assembly and use shop air to clear debris from the passages.

4. Check the threads in all cylinder head ports for galling (e.g. abrasion, chaﬁ ng). Minor thread chasing (damage) is permitted.

INSPECTION OF PARTS

CYLINDER HEAD, COOLING PLATE AND VALVE PLA TE ASSEMBLY

1. Carefully inspect the head gasket surfaces on the cylinder head for deep gouges and nicks. Also, inspect the cylinder head for any cracks or port thread damage. If detected, the compressor must be replaced. If large amounts of carbon build-up are present in the discharge cavity such that it restricts the air ﬂ ow through the cylinder head, the compressor should be replaced.

2. Carefully inspect both sides of the gasket surfaces on the cooling plate for deep gouges and nicks. Also, inspect the cooling plate for any cracks or other damage. If damage is found, the compressor must be replaced.

3. Carefully inspect the valve plate assembly gasket surfaces (both sides) for deep gouges and nicks. Pay particular attention to the gasket surface. An inlet reed valve gasket (7) is used between the valve plate assembly and crankcase. These gasket surfaces must be smooth and free of all but the most minor scratches. If excessive marring or gouging is detected, the compressor must be replaced. If large amounts of carbon build-up are present on the two main surfaces, in the two discharge valve holes or between the discharge valve and the discharge seat, the compressor should be replaced.

REAR END COVER

Check for cracks and external damage. Check the crankshaft rear bearing diameter in the rear end cover for excessive wear, ﬂ at spots or galling. Check the hydraulic pump attachment pilot and threaded holes for damage. Minor thread chasing is permitted, but do not re-cut the threads. If any of these conditions are found, replace the compressor.

CRANKCASE

Check the cylinder head gasket surface on the deck (top) of the crankcase for nicks, gouges, and marring. A metal gasket is used to seal the cylinder head to the crankcase. This surface must be smooth and free of all but the most minor scratching. If excessive marring or gouging is detected, the compressor must be replaced.

Check the condition of the two countersunk holes on the deck of the crankcase that retain the o-rings (8) and prevent coolant leakage between the valve plate assembly and the crankcase. The surface in contact with the o-ring should be smooth and free of any scratches and gouges that could cause leakage around the o-rings.

ASSEMBLY

General Note: All torques speciﬁ ed in this manual are assembly torques and typically can be expected to fall off after assembly is accomplished. Do not re-torque after initial assembly torques fall unless instructed otherwise. A compiled listing of torque speciﬁ cations is presented on page 13.

INCH POUNDS TO FOOT POUNDS

To convert inch pounds to foot pounds of torque, divide inch pounds by 12.

Example: 12 Inch Pounds = 1 Foot Pound 12

FOOT POUNDS TO INCH POUNDS

To convert foot pounds to inch pounds of torque, multiply foot pounds by 12.

Example: 1 Foot Pound x 12 = 12 Inch Pounds

CRANKCASE FRONT COVER

1. Position the new cover (9) over the hole in the front of the crankcase. Using a rubber mallet, drive the cover into the hole in the front of the crankcase until the outside diameter of the cover is ﬂ ush with cast surface.

CRANKCASE SIDE COVER

1. Position the gasket (11) on the crankcase side cover. Install the crankcase side cover on the side of the crankcase using the 6 cap screws previously removed. “Snug” all 6 cap screws then torque to 101 to 1 12 inch

pounds (1 1.4 - 12.6 Nm). When torquing the bolts, it is best to start with the two mid bolts then use a crossing pattern with the four remaining bolts.

REAR END COVER

1. Install the o-ring (10) on the rear end cover.

2. Orient the rear end cover to the crankcase using the reference marks made during disassembly. Carefully install the rear end cover in the crankcase making certain not to damage the crankshaft bearing surface.

3. Install the two end cover cap screws. Refer to Figure 9 to ensure that the two cap screws are installed in the proper crankcase bolt holes. “Snug” the screws, then tighten to between 195 and 212 inch pounds

(22-24 Nm).

CYLINDER HEAD, COOLING PLATE & VALVE PLA TE ASSEMBLY

1. Install the two crankcase o-rings (8) into the countersunk holes on the deck of the crankcase.

2. Note the position of the two protruding crankcase alignment pins on the deck (top) of the crankcase. Install the metal inlet reed valve gasket (7) over the alignment pins on the crankcase; being careful not to disturb the crankcase o-rings (8).

3. Position the valve plate assembly on the crankcase so that the alignment pins in the crankcase ﬁ t into the corresponding holes in the valve plate assembly.

4. Position the embossed metal head gasket (5) over the alignment bushings protruding from the top of the cooling plate. Position the embossed metal head gasket (6) over the alignment bushings on the opposite side of the cooling plate. When properly positioned, the outline of the two embossed gaskets match the outline of the cooling plate and the machined sealing surfaces on the cooling plate will be covered by the embossed metal gasket material. Important: The two gaskets are different and must be installed on the proper side of the cooling plate for the compressor to function properly.

See Figure 8

5. Install the cooling plate with the pre-installed head gaskets (5 and 6) onto the valve plate assembly. Align the alignment bushings on the cooling plate over the oversized countersunk holes of the valve plate assembly . Again, when properly installed, the outline of the cooling plate matches the outline of the valve plate assembly.

6. Position and install the cylinder head over the alignment bushings protruding from the cooling plate. When properly installed, the outline of the cylinder head assembly will match the outline of the cooling plate and valve plate assembly.

for proper head gasket positions.

7, 17

6, 16 5, 15

Sequence Torque (In-lbs) Torque (Nm)

1 through 10 177 20

11 through 20 265-292 30-33

FIGURE 11 - CYLINDER HEAD BOLT TORQUE SEQUENCE

1, 11

4, 14 8, 182, 1210, 20

9, 193, 13

Note: To assist with correct installation, the alignment

bushings in the cooling plate only ﬁ t into two of the four corner head bolt holes on the valve plate assembly and the cylinder head.

7. Install the eight long hex head cap screws (3) into the cylinder head. Note: A light ﬁ lm of oil should be

applied to the threads of these cap screws prior to installing. Oil should not be applied to any of the other hardware.

8. Install the two short hex head cap screws (4) into the cylinder head. Important: The two short hex head cap screws (4) must be installed in hole positions designated as sequence “6,16” and “5,15” in Figure 1 1.

9. “Snug” all the hex head cap screws, then tighten to a torque of between 265 to 292 inch pounds (30-33 Nm) using the torque sequence deﬁ ned in Figure 11.

10. Install the washer (1) and safety valve (2) in the side (discharge) port identiﬁ ed by the number '2' on the cylinder head (3) as shown in Figure 11, then tighten to a torque not to exceed 66 foot pounds (90 Nm).

INSTALLING THE COMPRESSOR

1. Apply a liquid gasket sealant to the compressor / engine mounting interface (Refer to Figure 3 for compressor mounting face). Follow the “Engine or Vehicle Manufacturers guidelines for the proper liquid gasket sealant material and application procedure.

2. Secure the compressor on the engine mounting interface using the six mounting bolts. NOTE: There are two short bolts and four long bolts. Be sure the use the proper length bolt for the crankcase bolt holes. Run each of the bolts down ﬁ nger tight, making sure not to smear the liquid gasket material on the sealing surface. Once the bolts are all ﬁ nger tight; tighten the mounting bolts per Engine Manufacturers recommended torquing sequence and torque requirements.

3. Install any supporting brackets on the compressor in the same position(s) noted and marked during removal.

4. Inspect all air and coolant lines and ﬁ ttings before reconnecting them to the compressor. Make certain o-ring seals are in good or new condition, the threads are clean and the ﬁ ttings are free of corrosion. Replace as necessary.

5. Install the discharge and coolant ﬁ ttings, if applicable, in the same position on the compressor noted and marked during disassembly . See the Torque Speciﬁ cations for various ﬁ tting sizes and types of thread at the rear of this manual. Tighten all hose clamps.

6. Before returning the vehicle to service, perform the Operation and Leakage Tests speciﬁ ed in this manual. Pay particular attention to all lines and hoses disconnected during the maintenance and check for air, oil, and coolant leaks at compressor connections and the compressor engine interface. Also check for noisy operation.

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