radiator JEEP CHEROKEE 1988 Service Repair Manual
[x] Cancel search | Manufacturer: JEEP, Model Year: 1988, Model line: CHEROKEE, Model: JEEP CHEROKEE 1988Pages: 1378, PDF Size: 19.9 MB
Page 5 of 1378

specification. Install front cover oil seal. See FRONT COVER OIL SEAL
Remove front cover seal installer.
4) Reverse removal procedures. Lubricate vibration damper
retaining bolt with oil prior to installation. Tighten bolts to
specification.
FRONT COVER OIL SEAL
Removal & Installation
1) Remove vibration damper. Using Seal Remover (J-9256),
remove seal from front cover. Position new seal on Front Cover Seal
Installer (J-22248) with lip facing outward.
2) Apply sealant to seal outer diameter. Lightly coat
crankshaft with oil. Place front cover seal installer on front of
crankshaft. Tap seal into front cover. Remove seal installer. Lightly
coat seal contact area of vibration damper with oil.
3) Install key in crankshaft (if removed). Install vibration\
damper. Lubricate vibration damper bolt with oil. Install retaining
bolt and washer. Tighten to specification.
CAMSHAFT & TIMING GEAR
Removal
1) Drain cooling system. Remove radiator. Remove engine front
cover. See ENGINE FRONT COVER. Remove distributor. Remove fuel pump
(if equipped with mechanical pump). Remove rocker arms and pushrods.
See ROCKER ARMS & BRIDGE under VALVES.
2) Remove valve lifters. Mark lifters for location. Remove
crankshaft oil slinger. Pull chain tensioner block toward tensioner
lever to compress spring. Hold block and move tensioner lever to lock
position. See Fig. 3.
3) Rotate crankshaft and align timing marks on crankshaft and
camshaft gears. Remove camshaft gear retaining bolt. Remove gears and
timing chain. Remove camshaft.
Fig. 3: Location of Chain Tensioner Lock
Courtesy of Chrysler Motors.
Inspection
Inspect camshaft for flaking, lobe wear or worn bearing
Page 12 of 1378

1) Drain cooling system. Remove fan shroud and drive belts.
Remove fan assembly.
2) Disconnect heater hoses and lower radiator hose at water
pump. Remove water pump retaining bolts. Remove water pump.
Installation
Clean all gasket surfaces. Install water pump. Tighten bolts
to specification. Ensure pump turns freely. Reverse removal
procedures. Fill and purge air from cooling system.
NOTE: It may be necessary to remove heater hose to remove trapped
air if system cannot be purged using following procedures.
Cooling System Air Purge (Vehicles With Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Install
coolant caps. Operate engine to normal operating temperature. Shut off
engine and allow system to cool. Add coolant to recovery bottle.
Repeat procedure to obtain correct coolant level.
Cooling System Air Purge (Vehicles Without Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Operate
engine to normal operating temperature with radiator cap removed. Add
necessary coolant and install radiator cap.
NOTE: For further information on cooling system capacities and
other cooling system components, see ENGINE COOLING SYSTEMS
article.
ENGINE OILING
CRANKCASE CAPACITY
Crankcase capacity is 4 qts. (3.8 L) with oil filter change.
NORMAL OIL PRESSURE
Normal oil pressure should be 13 psi (.91 kg/cm) at 600 RPM
or 37-75 psi (2.6-5.3 kg/cm) at 1600 RPM.
OIL PRESSURE REGULATOR VALVE
Oil pressure regulator valve is located in oil pump body and
is nonadjustable.
OILING SYSTEM
Engine lubrication is provided by the distributor driven
gear-type oil pump. Oil is supplied through the full-flow oil filter
and into an internal oil passage. Internal passage runs along right
side of block and intersects lifter bores.
Oil is then routed to camshaft and crankshaft bearings. Oil
is supplied to rocker arms from the hydraulic lifters and through the
push rods. By-pass valves are located in oil filter mounting and oil
pump.
OIL PUMP
Removal
Remove oil pan. See OIL PAN REMOVAL article. Remove oil pump
Page 60 of 1378

care not to damage seal area. Position new seal on Front Cover Seal
Installer (J-22248) with lip facing outward.
2) Apply sealant to seal outer diameter. Lightly coat
crankshaft with oil. Place front cover seal installer on front of
crankshaft. Tap seal into front cover. Lightly coat seal contact area
of vibration damper with oil.
3) Install key in crankshaft (if removed). Install vibration\
damper. Lubricate vibration damper bolt with oil. Install retaining
bolt and washer. Tighten to specification.
TIMING CHAIN & SPROCKET
Removal
1) Drain cooling system. Remove radiator. Remove engine front
cover. See ENGINE FRONT COVER in this article. Remove oil slinger.
Rotate crankshaft until timing marks on sprockets are aligned. See
Fig. 4 .
2) Remove camshaft sprocket bolt. Remove timing chain and
both sprockets as an assembly.
Installation
Install timing chain and sprockets. Ensure timing marks are
aligned. See Fig. 4. Install camshaft sprocket bolt. Tighten bolts to
specification. Install new front cover oil seal. Reverse removal
procedure for remaining components.
Fig. 4: Timing Chain & Sprocket Alignment
Courtesy of Chrysler Motors.
CAMSHAFT
Page 61 of 1378

Removal
1) Drain cooling system. Remove radiator. Discharge A/C
system if necessary. Remove A/C condenser and receiver assembly (if
equipped). Remove fuel pump (if equipped with mechanical pump),
ignition wires and distributor.
2) Remove cylinder head. See CYLINDER HEAD in this article.
Remove hydraulic lifters. Using Lifter Remover/Installer (J-21884),
remove lifters. Mark lifter location for reassembly reference.
3) Remove engine front cover. See ENGINE FRONT COVER in this
article. Remove timing chain and sprockets. Remove front bumper and
grille (if necessary). Carefully remove camshaft.
Inspection
Inspect camshaft for flaking, lobe wear or worn bearing
journals. Replace if not within specification. See ENGINE
SPECIFICATIONS tables.
Installation
Lubricate camshaft and install into place. Use care not to
damage camshaft bearings. Reverse removal procedure to complete
installation. Tighten bolts to specification.
Camshaft Bearing
Replace camshaft bearings using camshaft bearing
remover/installer. Ensure oil holes are aligned after installation.
OIL PAN
See OIL PAN REMOVAL at end of ENGINE section.
PISTON & ROD
NOTE: Mark piston cylinder location for reassembly reference.
Install pistons in original cylinder location.
Removal
1) Remove cylinder head. See CYLINDER HEAD in this article.
Remove oil pan. See OIL PAN REMOVAL at end of ENGINE section. Remove
ridge or deposits from cylinder bore.
2) Mark connecting rod and piston for cylinder
identification. Remove bearing cap. Remove piston and rod assembly.
CAUTION: Arrows on top of piston must point toward front of engine.
Oil squirt holes in connecting rod must face camshaft side
of engine.
Installation
1) Ensure ring end gap and side clearance are within
specification. See ENGINE SPECIFICATIONS tables. Install rings on
piston. Position ring end gaps at specified areas. See Fig. 5. Ring
gaps may vary 20 degrees from positions illustrated.
Page 67 of 1378

Removal
Drain cooling system. Disconnect radiator and heater hoses
from pump. Remove drive belt(s). Remove fan shroud. Remove fan
assembly. Remove electric cooling fan (if equipped). Remove power
steering bracket from water pump. Remove water pump and gasket.
Installation
Ensure gasket surfaces are clean. Install water pump. Tighten
bolts to specification. Ensure pump turns freely. Reverse removal
procedures. Fill and purge air from cooling system.
NOTE: It may be necessary to remove heater hose to remove trapped
air if system cannot be purged using following procedures.
Cooling System Air Purge (Vehicles W/Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Install
coolant caps. Operate engine to normal operating temperature. Shut off
engine and allow system to cool. Add coolant to recovery bottle.
Repeat procedure to obtain correct coolant level.
Cooling System Air Purge (Vehicles W/O Coolant Recovery)
Fill system to proper level. Place heater control to "HEAT"
position and temperature control to "WARM" or "HIGH" position. Operate
engine to normal operating temperature with radiator cap removed. Add
necessary coolant and install radiator cap.
NOTE: For further information on cooling systems, see appropriate
article in the ENGINE COOLING section.
LUBRICATION
CRANKCASE CAPACITY
Crankcase capacity for 4.0L is 5 1/2 qts. (5.2L) or 5 qts.
(4.7L) for 4.2L with oil filter change.
NORMAL OIL PRESSURE
Normal oil pressure should be 37-75 psi (2.6-5.3 kg/cm)
maximum above 1600 RPM. Minimum oil pressure should be 13 psi (.9
kg/cm
) at 600 RPM.
OIL PRESSURE REGULATOR VALVE
Oil pressure regulator valve is located in pump body. Valve
is nonadjustable and serviced as an assembly.
ENGINE OILING SYSTEM
Engine lubrication is provided by the distributor driven
gear-type oil pump. Oil is supplied through the full-flow oil filter
and into an internal oil passage. Internal passage provides oil to the
lifter bores. Oil is then routed to camshaft and crankshaft bearings.
Oil is supplied to rocker arms from the hydraulic lifters and through
the push rods.
OIL PUMP
Removal
Remove oil pan. See OIL PAN REMOVAL in this section. Remove
Page 105 of 1378

of the scale, a symbol for defroster indicates defrost position. In
"BI-LEVEL" position, a mixture of floor heat and defroster air is
obtained.
The lower temperature control lever operates blend-air door
in heater core housing. At full right position, all air is directed
through heater core, providing maximum heat flow. At full left
position, all air is directed around heater core providing fresh air.
Control can be set in any intermediate position to provide a blend of
heated and unheated air. Heater must be in heat or defrost mode before
any air can enter vehicle.
TROUBLE SHOOTING
See JEEP TROUBLE SHOOTING at the end of this article.
REMOVAL & INSTALLATION
CONDENSER
Removal (Cherokee, Comanche & Wagoneer) NOTE: On these
models, condenser and receiver-drier are replaced
as a unit.
1) Drain radiator. Disconnect fan shroud and radiator hoses.
Disconnect automatic transmission cooler lines (if equipped).
Discharge A/C system using approved refrigerant recovery/recycling
equipment.
2) Disconnect A/C hoses from condenser. Unplug low pressure
switch. Remove radiator and condenser as an assembly. Detach condenser
retaining bolts. Separate condenser from radiator. Remove receiver-
drier from condenser.
NOTE: Plug receiver-drier openings whenever unit is removed from
condenser. Add 1 oz. of refrigerant oil (AMC No. 8132400) to
system when replacing condenser.
Installation
To install, reverse removal procedure. Fill radiator.
Evacuate, leak test, recharge and check A/C system operation.
Removal (Wrangler)
1) Discharge system (slowly to prevent loss of compressor
oil) using approved refrigerant recovery/recycling equipment. Drain
coolant. Remove fan shroud and radiator. Disconnect pressure line at
condenser. Remove condenser mounting screws. Tilt bottom of condenser
toward engine.
2) From underside of vehicle, disconnect hose attaching
receiver-drier to evaporator. Plug all openings to prevent entry of
dirt or moisture. Remove receiver-drier and condenser assembly. Remove
receiver-drier from condenser.
Installation
To install, reverse removal procedure. Fill radiator.
Evacuate, leak test, recharge and check A/C system operation.
RECEIVER-DRIER
NOTE: On Cherokee, Comanche and Wagoneer, receiver-drier is
removed with condenser and radiator as an assembly.
Removal (Wrangler)
Page 118 of 1378

HEATER HOSES
HIGH PRESSURE RELIEF VALVES (HPRV)
IDLERS
IN-LINE FILTERS
METAL FITTINGS
METAL LINES
MIX AND AIR CONTROL DOORS (BLEND DOORS)
O-RINGS
ORIFICE TUBES
PILOT-OPERATED ABSOLUTES (POAS)
PLENUMS
PRESSURE CONTROL VALVES
PRESSURE SENSORS
PULLEYS
RADIATORS
RECEIVER-DRIERS
REFRIGERANT
REFRIGERANT OIL
RELAYS
SEALS
SERVICE PORTS
SPRING LOCK COUPLINGS
SUCTION THROTTLING VALVES (STVS)
SWITCHES (ELECTRICAL)
TENSIONERS
THERMISTORS AND PRESSURE SENSORS
THERMOSTATS AND HOUSINGS
VACUUM HOSES AND TUBES
VACUUM RESERVOIRS
VACUUM TUBES
VALVES IN RECEIVER (VIRS)
WATER PUMPS (ELECTRIC AUXILIARY)
WIRING HARNESSES AND CONNECTORS
MOTORIST ASSURANCE PROGRAM (MAP)
OVERVIEW
The Motorist Assurance Program is the consumer outreach
effort of the Automotive Maintenance and Repair Association, Inc.
(AMRA). Participation in the Motorist Assurance Program is drawn from
retailers, suppliers, independent repair facilities, vehicle
manufacturers and industry associations.
Our organization's mission is to strengthen the relationship
between the consumer and the auto repair industry. We produce
materials that give motorists the information and encouragement to
take greater responsibility for their vehicles-through proper,
manufacturer-recommended, maintenance. We encourage participating
service and repair shops (including franchisees and dealers) to adopt
(1) a Pledge of Assurance to their Customers and (2) the Motorist
Assurance Program Standards of Service. All participating service
providers have agreed to subscribe to this Pledge and to adhere to the
promulgated Standards of Service demonstrating to their customers that
they are serious about customer satisfaction.
These Standards of Service require that an inspection of the
vehicle's (problem) system be made and the results communicated to the\
customer according to industry standards. Given that the industry did
not have such standards, the Motorist Assurance Program successfully
promulgated industry inspection communication standards in 1994-95 for
the following systems: Exhaust, Brakes, ABS, Steering and Suspension,
Engine Maintenance and Performance, HVAC, and Electrical Systems.
Further, revisions to all of these inspection communication standards
Page 146 of 1378

functioning ............ A ... Require repair or replacement
of hardware.
Bearing noisy ........... 2 ............ Suggest replacement.
Bearing seized .......... A .. Require repair or replacement.
Bearing worn ............ 1 ............ Suggest replacement.
Cracked ................. A ............ Require replacement.
Loose ................... A .. Require repair or replacement.
Missing ................. C ............ Require replacement.
Pulley damaged, affecting
belt life .............. A ............ Require replacement.
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RADIATORS
RADIATOR INSPECTION \
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Condition Code Procedure
Air flow obstruction .... A ................. Require repair.
Application incorrect ... B ............ Require replacement.
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
missing ................ C .......... Require replacement of
hardware.
Attaching hardware not
functioning ............ A .. Require repair or replacement
of hardware.
Connection leaking ...... A .. Require repair or replacement.
Corroded ................ 1 .. Suggest repair or replacement.
Drain inoperative ....... A .. Require repair or replacement.
Fins damaged, affecting
performance ............ A .. Require repair or replacement.
Fins damaged, not
affecting performance .. .. ........ No service suggested or
required.
Internal oil cooler
leaking ................ A .. Require repair or replacement.
Internal restrictions ... B .. Require repair or replacement.
Leaking ................. A .. Require repair or replacement.
Threads damaged ......... A .. Require repair or replacement.
Threads stripped (threads
missing) ............... A .. Require repair or replacement.
Tubes damaged, affecting
performance ............ A .. Require repair or replacement.
Tubes damaged, not
affecting performance .. .. ........ No service suggested or
required.
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RECEIVER-DRIERS
NOTE: For VIRs, see VALVES IN RECEIVER (VIRS) .
RECEIVER-DRIER INSPECTION
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Condition Code Procedure
Attaching hardware
broken ................. A ... Require repair or replacement
of hardware.
Attaching hardware
Page 430 of 1378

2) On models with 2-piece shafts, rotate transmission yoke
until trunnion is in horizontal plane. Install front drive shaft with
"U" joint trunnion in vertical plane. Connect bearing support to
crossmember.
3) Ensure that front face of bearing support is perpendicular
(90 degrees) to centerline of drive shaft. Install rear drive shaft
with "U" joint trunnion of slip joint in vertical plane.
4) Set differential pinion yoke trunnion in vertical plane.
Connect rear drive shaft to pinion yoke. If 2-piece shaft is correctly
installed, centerline of trunnions at each end of individual shafts
will be parallel. See Fig. 3.
Fig. 3: Phase Alignment Of 2-Piece Drive Shafts
Trunnion yoke ears on each shaft must be parallel.
DRIVE SHAFT BALANCE TEST
1) Drive shaft imbalance may often be cured by disconnecting
shaft and rotating it 180 degrees in relation to other components.
Test by raising rear wheels off ground, and turning shaft with engine.
NOTE: DO NOT run engine without ram airflow across radiator for
prolonged periods, as overheating of engine or transmission
may occur.
2) On most models, balance testing may be done by marking
shaft in 4 positions, 90 degrees apart. Place marks approximately 6"
forward of weld, at rear end of shaft. Number marks one through 4.
3) Place screw-type hose clamp so clamp head is in number one
position, and rotate shaft with engine. If there is little or no
change, move clamp head to No. 2 position, and repeat test.
4) Continue procedure until vibration is at lowest level. If
no difference is noted with clamp head moved to all 4 positions,
vibrations may not be drive shaft imbalance.
5) If vibration is lessened but not completely gone, place 2
clamps at that point, and run test again. Combined weight of clamps in
one position may increase vibration. If so, rotate clamps 1/2" apart,
above and below best position, and repeat test.
6) Continue to rotate clamps as necessary, until vibration is
at lowest point. If vibration level is still unacceptable, leave rear
clamp(s) in position and repeat procedure at front end of drive shaft.\
If vibration can be eliminated or reduced to acceptable levels using
this test procedure, send drive shaft out to be balanced.