1988 JEEP CHEROKEE drain bolt

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)

housing attaching nuts from studs on engine compartment side of dash
panel. Remove evaporator drain tube.
4) Remove right kick panel. Detach instrument panel support
bolt. Gently pull on right side of dash, then rotate housing downward
and toward rear of vehicle to disengage housing studs from dash panel.
Remove evaporator-blower housing.
5) To remove heater core, detach retaining screws. Remove
heater core by pulling straight out of housing. To remove evaporator
core, detach top housing retaining screws, then remove top of
evaporator housing.
6) Remove thermostatic switch and capillary tube. Detach 2
evaporator retaining screws and lift evaporator core from housing.
Remove expansion valve from evaporator.
Installation
1) To install components, reverse removal procedure. When
installing evaporator core, install thermostatic switch and capillary
tube before installing top of housing.
2) When installing heater core, ensure seal is properly
cemented in place to prevent it from moving when blower assembly is
installed. Evacuate, leak test, recharge and check A/C system
operation.
NOTE: The evaporator housing mounting location is similar to
Wrangler, except blower motor is mounted horizontally to
firewall.
Removal (Wrangler)
1) Discharge system using approved refrigerant
recovery/recycling equipment. Disconnect inlet line at compressor.
Disconnect hose, at quick-disconnect coupling, between receiver-drier
and evaporator. Remove hose clamps and dash grommet retaining screws.
See Fig. 2 .
Fig. 2: Wrangler Evaporator Housing Mounting Screw Locations
Courtesy of Chrysler Motors.
NOTE: It is not necessary to discharge system to service blower
motor. Evaporator housing may be lowered from instrument









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Compressor Runs Rough
* Incorrect oil or refrigerant level.
* Internal compressor damage.
Compressor Intermittent or Inoperative
* Drive belt slipping.
* Faulty clutch air gap.
* Clutch coil wiring broken or frayed.
Noisy Compressor
* Mounting bolts loose.
* Clutch slipping.
* Improper charge in system.
* Bad clutch or pulley bearings.
* Incorrect oil level.
* Valve plate damaged.
* Piston slap.
Excessive Vibration
* Incorrect belt tension.
* Clutch loose.
* Pulley misaligned.
* System overcharged.
A/C Air Flow Stops on Acceleration
* Defective vacuum storage tank.
* Vacuum line separated or defective.
* Vacuum switch defective.
* Vacuum leak.
High Suction Pressure with Very Low Discharge Pressure
* Valve plate or gasket broken or deformed.
Very Low Suction and Discharge Pressure
* Low refrigerant charge.
* Compressor leak.
* System leak.
Heater Control Valve Does Not Close with Vacuum Applied
* Faulty heater control valve.
No Vacuum at Heater Control Valve with Lever at Extreme Left
* Vacuum source hose disconnected.
* Leaking vacuum hose.
* Faulty check valve.
* Control panel switch defective or misadjusted.
Frozen Evaporator Core
* Faulty thermostat.
* Thermostat capillary tube improperly installed.
* Thermostat not adjusted properly.
Condensation Dripping in Passenger Compartment
* Drain hose plugged or improperly installed.
* Insulation missing or improperly installed.









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TESTING
Note: The following test applies to all Jeep models except Cherokee
and Wagoneer.

2) Loosen discharge port valve slightly. Loosen valve port
cap to allow refrigerant to force out air from compressor. Back-seat
the discharge valve and tighten the port cap. Compressor is ready for
service.
REFRIGERATION OIL
Only new, pure, moisture-free refrigeration oil should be
used in the air conditioning system. This oil is highly refined and
dehydrated (moisture content less than 10 parts per million).
Refrigeration oil container must be kept tightly closed at
all times when not in use, or moisture will be absorbed from the air
and introduced into the refrigeration system.
NIPPONDENSO 10-CYLINDER
SHAFT SEAL
NOTE: Check compressor refrigerant oil level when replacing seals.
See COMPRESSOR REFRIGERANT OIL CHECKING article in this
section.
Removal
1) Hold clutch hub stationary and remove center nut. Screw
remover into center of hub. Turn center bolt to remove pressure plate.
2) Remove shims from shaft. Remove snap ring from inside of
pulley. Tap pulley off of shaft with plastic mallet. Be careful not
to distort pulley while removing.
3) Disconnect clutch coil wires from compressor housing.
Remove snap ring inside coil and lift coil off compressor. Pry dust
seal out from around compressor shaft (if equipped).
4) Place shaft key remover on shaft and turn to remove key.
Remove drain plug (if equipped). Remove bolts holding service valves
to body of compressor and remove valves. Discard "O" rings. Drain oil
out of compressor.
5) Remove 6 through bolts from front head of compressor and
discard washers. Tap head loose from compressor, being careful not to
scratch sealing surfaces. Remove snap ring (if equipped) from front
housing. Press seal plate out. Remove seal from shaft. See Fig. 1.
Installation
1) Lubricate shaft seal with clean refrigerant oil. Place on
compressor shaft. Lubricate seal plate (and "O" ring, if equipped) and\
install in front housing. Install snap ring (if equipped).
2) Place front housing on compressor body. Using new
washers, install through bolts. Tighten bolts evenly and alternately
to 18 ft. lbs. (24 N.m). Install shaft key with installer and plastic
mallet. Insert dust seal into front of compressor.
3) Install drain plug using new gasket. Add correct amount
of refrigerant oil to compressor. If service valves were removed,
coat new "O" rings with refrigerant oil and install service valves.
4) Place clutch coil on compressor and install snap ring.
Install shims on shaft to adjust clearance between pressure plate and
rotor to .016-.028" (.41-.71 mm). Tighten shaft nut to 12 ft. lbs. (1\
6
N.m). See REFRIGERANT OIL & R-12 SPECIFICATIONS table for system
capacities.
SANKYO/SANDEN 5-CYLINDER COMPRESSOR SERVICING
NOTE: During the past year, Sankyo International (USA), Inc. has
changed its name to Sanden International (USA), Inc.

Information pertaining to Sanden compressors in this article,
will be found in earlier articles under Sankyo compressors.
AMERICAN MOTORS & JEEP WITH 5-CYLINDER COMPRESSOR
Compressor Overhaul
1) After the compressor and system have been run, stop the
engine. Slowly discharge system using approved refrigerant
recovery/recycling equipment. Clean and cool dipstick with R-12.
2) Loosen the compressor mounting bolts, remove the drive
belt, and move the compressor to a bench for easiest and most accurate
measurement. Position the compressor so that the oil fill plug is at
top dead center.
3) Thoroughly clean the oil fill plug and the area around it.
Loosen the fill plug slowly to allow trapped refrigerant pressure to
escape through the loosened threads.
4) The front plate hub has a lobe, which is indexed (notched)\
180
from TDC of the cam rotor. Rotate the hub plate lobe until the
index notch is 110 from bottom center. See Fig. 1. Check this
position by looking through the oil fill hole and noting that the ball
end of the top piston rod lines up with the fill hole.
5) Looking at the front end of the compressor, insert the
dipstick diagonally from upper left to lower left until the dipstick
stop contacts the filler hole surface. Remove dipstick and note oil
level. Oil level should be between the 4th and 6th increment on the
dipstick (3-4 ounces). Add oil as necessary.
Compressor Replacement
If system was opened by a leak or so quickly that oil was
lost, install new compressor with all the oil it contains. If system
was opened slowly and oil was not lost, drain oil from new compressor
and measure. Reinstall 6 ounces of oil back into new compressor prior
to installation.
Component Replacement
If a hose, receiver-drier, condenser, expansion valve or
evaporator core requires replacement, add 1 ounce of new oil for each
new component installed.
Compressor Oil Check
1) Discharge system, using approved refrigerant
recovery/recycling equipment, or isolate compressor. Remove oil filler
plug. Look through oil filler plug hole and rotate clutch front plate
to position piston connecting rod in center of oil filler plug hole.
2) Insert dipstick (J-29642-12) through oil filler plug hole\
to the right of piston connecting rod until dipstick stop contacts the
compressor housing.
3) Remove dipstick and count number of increments covered
with oil. If compressor is properly filled, oil will cover 4-6
increments on the dipstick. Adjust oil level as necessary.

Removal
1) Raise and support vehicle. Remove drain plug and drain
transmission fluid. Remove bolts and oil pan. Remove bolts, oil screen
and gasket.
2) Disconnect electrical connectors from valve body solenoid.
Mark electrical connector location for reassembly reference if more
than one valve body solenoid is being removed. Remove bolt, valve body
solenoid and "O" ring.
CAUTION: DO NOT allow components to fall from valve body when
removing valve body solenoid.
Installation
1) To install, reverse removal procedure using NEW "O" ring
and NEW gaskets. Tighten valve body solenoid bolt and oil screen bolt
to specification. See TORQUE SPECIFICATIONS at end of article.
2) Ensure magnet is installed in oil pan and does not
interfere with valve body oil tubes. Apply 1/8" bead of Loctite 599
sealant on oil pan mounting flange. Install oil pan. Install and
tighten bolts to specification. See TORQUE SPECIFICATIONS.
3) Install NEW gasket and drain plug. Tighten drain plug to
specification. See TORQUE SPECIFICATIONS at end of article. Fill
transmission to proper fluid level with Mopar Dexron-IIE/Mercon ATF.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS








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Application Ft. Lbs. (N.m)
Drain Plug ....................................... 15 (20)
INCH Lbs. (N.m)
Neutral Safety Switch Adjusting Bolt .......... 108 (12.2)
Neutral Safety Switch Retaining Nut ............. 61 (6.9)
Oil Pan Bolt .................................... 65 (7.3)
Oil Screen Bolt ................................. 84 (9.5)
Speed Sensor Bolt ............................... 65 (7.3)
Valve Body Solenoid Bolt ........................ 84 (9.5)









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Before bleeding system, exhaust all vacuum from power unit by
depressing brake pedal several times. Bleed master cylinder (if
equipped) with bleeder screws. Bleed slave cylinder on vehicles
equipped with remote mount power assist units. Bleed wheel cylinders
and calipers in sequence. See BLEEDING SEQUENCE table.
BLEEDING SEQUENCE TABLE









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Application Sequence
All Models ................................ RR, LR, RF, LF









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REMOVAL & INSTALLATION
DISC BRAKE CALIPER
Removal & Installation
Caliper removal and installation procedures are same as for
disc pad replacement. To remove caliper from vehicle, disconnect brake
line at caliper and cap hole to prevent contamination.
DISC BRAKE PADS
Removal
1) Drain 2/3 of brake fluid from master cylinder reservoir.
Raise vehicle and support with safety stands. Remove front wheel
assembly.
2) Place "C" clamp on caliper. Solid end of clamp should
contact back of caliper. Screw end should contact metal part of
outboard shoes.
3) Tighten "C" clamp until caliper forces piston to bottom of
bore. Remove both Allen head mounting bolts and lift caliper off
rotor. Support caliper out of the way.
4) On Grand Wagoneer, remove both brake pads from caliper.
Note spring position and support spring from inboard shoe. Remove
sleeves and bushings from caliper.
5) On all other models, hold anti-rattle clip against caliper
adapter and remove outer brake pad. Remove inner brake pad and anti-
rattle clip from caliper adapter.
Installation
1) To install, reverse removal procedure. On Grand Wagoneer,
lubricate new bushings, sleeves, bushing grooves, and small ends of
mounting bolts with silicone lubricant. Install rubber bushings in
caliper mounting ears.
2) On all other models, clean caliper mating surfaces on
adapter with a wire brush. Apply double sided adhesive tape to back
side of inner pad. Clean caliper piston surface. Lubricate caliper
mating surfaces on caliper adapter.
3) On all models, lubricate caliper mounting bolts using
brake corrosion lubricant and tighten mounting bolts. Add brake fluid
to reservoir. Apply brakes until brake pedal is firm. Check brake
fluid level.
DISC BRAKE ROTOR - WRANGLER
Removal
Raise and support vehicle. Remove front wheel and caliper.
Suspend caliper from frame or suspension. Remove rotor from hub.
Installation

Remove axle shaft oil seal from axle housing tube.
3) Place axle shaft in a vise. Drill a 1/4" (6.35 mm) hole
3/4 of the way through bearing retaining ring. Chisel off bearing
retaining ring. Do not use a torch. Press bearing off axle. Remove
seal and retainer plate.
Installation
Lubricate bearing and seal lip. Install retainer plate and
seal over axle. Press axle shaft bearing and retaining ring on shaft
simultaneously. Ensure bearing and ring are seated against axle shaft
shoulder. To complete installation, reverse removal procedure to
complete installation.
WHEEL CYLINDER
Removal
Remove wheel assemblies, brake drums and brake shoes.
Disconnect brake line at wheel cylinder. Do not bend brake line away
from cylinder. Remove cylinder-to-support plate bolts. Remove
cylinder.
Installation
To install, reverse removal procedure. Start brake line
fitting into cylinder before installing cylinder to support plate.
OVERHAUL
DISC BRAKE CALIPER
Disassembly
1) Clean caliper exterior with brake cleaning solvent. Drain
residual fluid from caliper and place caliper on a clean working
surface.
2) Remove piston from caliper by applying compressed air to
inlet port. Use just enough pressure to ease piston out of bore.
Protect piston from damage with folded shop towels. Do not try to
catch piston by hand.
3) Pry dust boot out of bore with screwdriver. Do not scratch
bore. Using a small plastic or wooden stick, pry piston seal from
bore. See Fig. 11. Remove bleeder screw, sleeves, and bushings.
Cleaning & Inspection
Clean all parts with brake cleaning solvent. Blow dry parts.
Check for damaged or worn parts. Stains on piston bore can be polished
with crocus cloth. Do not use emery cloth or any other abrasive.
Reassembly
1) Lubricate bore and new seal with brake fluid. Install seal
in groove using fingers. Lubricate piston with brake fluid. Slide
metal retainer portion of dust boot over open end of piston. Pull boot
rearward until boot lip seats in piston groove.
2) Push retainer portion of dust boot forward until boot is
flush with rim at open end of piston and boot fold snaps into place.
Insert piston in bore being careful not to unseat piston seal.
3) Push piston to bottom of bore using hammer handle.
Position dust boot retainer in counterbore at top of piston bore. Seat
dust boot retainer with Dust Boot Installer (J-22904 or J-33028).
Reverse removal procedure to complete installation.