Bendix Commercial Vehicle Systems BENDIX 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 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 ow into, and out of, the cylinder head and
crankcase water jacket. The compressor discharge valves
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
B
BENDIX PRODUCT - ASSY IN FRANCE
FIGURE 2 - NAMEPLATES
A
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
B
A
C
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 guidelines should be observed AT ALL TIMES:
▲ Park the vehicle on a level surface, apply the
parking brakes and always block the wheels.
Always wear personal protection equipment.
▲ Stop the engine and remove the 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.
▲ 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.
▲ 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, a Bendix® DRM™
dryer reservoir module, or a Bendix® AD-9si™ air
dryer, be sure to drain the purge reservoir.
▲ Following the vehicle manufacturer’s
recommended procedures, deactivate the
electrical system in a manner that safely removes
all electrical power from the vehicle.
▲ Never exceed manufacturer’s recommended
pressures.
▲ 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.
▲ Use only genuine Bendix® brand replacement
parts, components and kits. Replacement
hardware, tubing, hose, ttings, etc. must be of
equivalent size, type and strength as original
equipment and be designed speci cally for such
applications and systems.
▲ Components with stripped threads or damaged
parts should be replaced rather than repaired.
Do not attempt repairs requiring machining or
welding unless speci cally stated and approved
by the vehicle and component manufacturer.
▲ Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.
▲ 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.
▲ The power MUST be temporarily disconnected
from the radar sensor whenever any tests USING
A DYNAMOMETER are conducted on a Bendix
Wingman® Advanced™-equipped vehicle.
®
▲ You should consult the vehicle manufacturer's operating and service manuals, and any related literature,
in conjunction with the Guidelines above.
2
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
are part of the valve plate assembly. The inlet reed valve/
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 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.
3
D
D
S
C
S
UNL
UNL
RES
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
ex open. Atmospheric air ows through the open inlet valve
and 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 ow into the
discharge line and air brake system. See Figure 5.
C
Governor
UNL
S
21
22
Air Dryer
Front Service
Reservoir
Rear Service
DLU Valve
D
S
Compressor
Reservoir
FIGURE 6 - TYPICAL BENDIX® 720CC (DLU-STYLE) TWIN CYLINDER COMPRESSOR AIR CHARGING SYSTEM
4
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 (e.g. air dryer or DLU valve) in order to
control when the air is 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
ow out the exhaust port of the air dryer.
Safety
Valve Port
CYLINDER HEAD PORT IDENTIFICATION
The cylinder head connection ports are
identied 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 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 ange.
Note: The Bendix® 720cc compressor is a discharge
line unloader-style (DLU-style) unit. This means that the
compressor functions in a continuous pumping mode;
regardless of 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.
COOLING
The Bendix 720cc twin cylinder compressor is cooled both
by air owing through the engine compartment as it passes
the compressor's cast-in cooling ns, and by the 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
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
ow connections. Proper cooling is important in minimizing
discharge air temperatures – see the tabulated technical
data on page 13 of this manual for specic requirements.
5
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.
PREVENTIVE 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 Warranty Policy
before 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 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, chang 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 ow. Minimum coolant line
size is 3/8" Inside Diameter (I.D.) Check coolant lines for
internal clogging from rust scale. If coolant lines appear
suspicious, check the coolant ow and compare to the
tabulated technical data present in the back of this manual.
6
LUBRICATION INSPECTION
The compressor utilizes an internal oil feed design. Check
the exterior of the compressor (e.g. 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® PuraGuard® system can be used in
conjunction with a Bendix® 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
suspected excessive oil passing. The steps to be followed
when using the BASIC kit are presented in APPENDIX B.
®
BASIC™ kit — to help substantiate
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 ow out the exhaust port of the
air dryer. Refer to Figure 6.
Test and inspect the unloading system (e.g. 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 build-up 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.
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 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 certied 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
les. Subsequent build-up times throughout the vehicle’s
service life can then be compared to the rst one recorded.
(Note: the 40 second guide in the test above does not
apply to this build-up time.) If the performance degrades
signicantly over time, use the Advanced Troubleshooting
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 modications 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 Bendix Air
Brake System Handbook (BW5057) and on the back of
the Bendix Dual Circuit Brake System Troubleshooting
Card (BW1396).
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.
7
INLET & DISCHARGE VALVES
In order to test the inlet and discharge valves, it is necessary
to have shop air pressure and an assortment of 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 “In-Service 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
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.
4. Remove the discharge 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 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 to the engine manufacturer's 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 preassembled on the compressor.)
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.
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
8
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 identied by "Item" numbers 1 through 11.
Cylinder Head
3
4
1
2
Crankcase
Compressor
Drive Gear
Cooling
Plate
Valve Plate
Assembly
9
7
8
Crankcase
Side Cover
5
6
Crankcase
Alignment Pins
(x2) - one at
each end
10
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 Bendix® 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)
11
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
9
These items are also referenced in the following procedures
and are denoted by the numbers in parenthesis.
CYLINDER HEAD, COOLING PLATE & VALVE
PLATE 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.
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).
CRANKCASE FRONT COVER
1. Remove the cover (9) from the front of the crankcase.
Use a sharp, 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).
M10x1.5
Cap
Screws
(Larger)
M8x1.25
Cap
Screws
(Smaller)
FIGURE 9 - REAR END COVER ATTACHMENT BOLTS
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.
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 (e.g. 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.
10
9
FIGURE 10 - FRONT COVER
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
PLATE 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, chang). Minor thread chasing (damage)
is permitted.
INSPECTION OF PARTS
CYLINDER HEAD, COOLING PLATE AND VALVE
PLATE 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 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, 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 specied 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 specications is presented on
page 13.
INCH POUNDS TO FOOT POUNDS
To convert inch pounds (in-lbs) to foot pounds (ft-lbs) of
torque, divide inch-pounds by 12.
Example: 12 in-lbs = 1 ft-lbs
12
FOOT POUNDS TO INCH POUNDS
To convert foot pounds to inch pounds of torque, multiply
foot pounds by 12.
Example: 1 ft-lbs x 12 = 12 in-lbs
11
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 ush with the 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 six (6) cap screws previously
removed. “Snug” all six cap screws then torque to
97–115 in-lbs (11–13 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. Make 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 in-lbs (22-24
Nm).
CYLINDER HEAD, COOLING PLATE & VALVE
PLATE 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 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 for proper head gasket positions.
12
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.
Note: To assist with correct installation, the alignment
bushings in the cooling plate only 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 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 “3” and “8” in Figure 11.
9. To ensure the cylinder head cap screws are properly
torqued, the following three step procedure must be
adhered to. Each cap screw must be tightened a total
of three times. Referencing Figure 11, tighten each
screw—in numerical order—to the torque identied in
Step 1. Once all have been tightened follow the same
procedure for Steps 2 and 3.
10. Install the washer (1) and safety valve (2) in the side
(discharge) port identied 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 manufacturer's 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 to use
the proper length bolt for the crankcase bolt holes. Run
each of the bolts down nger tight, making sure not to
smear the liquid gasket material on the sealing surface.
Once the bolts are all nger tight, tighten the mounting
bolts per the engine manufacturer's recommended
torquing sequence and torque requirements.
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