1988 JEEP CHEROKEE wheel bolts

TORQUE SPECIFICATIONS TABLE








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Application Ft. Lbs. (N.m)
Camshaft Sprocket Bolt .......................... 80 (109)
Connecting Rod Cap Nut ........................... 33 (45)
Crankshaft Pulley-to-Damper Bolt ................. 20 (27)
Cylinder Head Bolt
4.0L
No. 11 .................................... 100 (135)
All Others ................................. 110 (149)
4.2L
No. 11 ..................................... 75 (102)
All Others .................................. 85 (115)
Exhaust Pipe-to-Manifold Bolt .................... 20 (27)
Fan & Hub Bolt ................................... 18 (24)
Flywheel-to-Crankshaft Bolt .................... 105 (142)
Fuel Rail Bolt ................................... 20 (27)
Intake & Exhaust Manifold Bolt
4.0L
Exhaust Manifold Bolts 1-5 ................... 23 (31)
Exhaust Manifold Bolts 6-7 .................. 17 (23)
Exhaust Manifold Bolts 8-11 ................. 23 (31)
Exhaust Manifold Bolts 12-13 ................ 30 (41)
4.2L ........................................... 23 (31)
Main Bearing Cap Bolt
Step 1 ......................................... 40 (54)
Step 2 ......................................... 70 (95)
Step 3 ........................................ 80 (109)
Oil Pump Attaching Bolt
Short .......................................... 10 (14)
Long ........................................... 17 (23)
Oxygen Sensor .................................... 35 (47)
Rocker Arm Bolt .................................. 19 (26)
Vibration Damper Bolt ....................... (1) 80 (109)
Water Pump Bolts ................................. 13 (18)
INCH Lbs. (N.m)
Engine Front Cover
Bolt ............................................ 60 (7)
Studs ......................................... 192 (22)
Oil Pan Bolt
1/4" X 20 ....................................... 84 (9)
5/16" X 18 .................................... 132 (15)
Oil Pump Cover Bolt ............................... 70 (8)
Valve Cover Bolt .................................. 55 (5)
( 1) - Clean and lubricate with oil prior to tightening.









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ENGINE SPECIFICATIONS
GENERAL ENGINE SPECIFICATIONS
GENERAL SPECIFICATIONS TABLE








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Application In. (mm)
4.0L
Displacement

ECU signal line and the other end connected to ground. As throttle
valve angle changes, a return voltage is sent back to the ECU through
the third wire. Output voltage to the ECU is about one volt when
throttle valve is at idle position, and about 5 volts when throttle
valve is at wide open throttle.
A dual TPS is used on automatic transmission equipped models.
The additional sensor provides throttle position information to the
transmission.
Knock Sensor
A knock sensor is mounted on the lower left side of block,
just above the oil pan. This sensor detects abnormal engine vibration
due to "detonation" and/or "pre-ignition". The knock sensor supplies
detonation information to the ECU. The ECU then alters ignition timing
as needed to maintain maximum timing under most operating conditions.
Park/Neutral (P/N) Switch
The P/N switch is mounted in automatic transmission equipped
vehicles. The switch indicates when the transmission is in Park or
Neutral.
Speed Sensor
The speed sensor is a nonadjustable sensor attached to the
flywheel/drive plate housing with special shoulder bolts. This sensor
provides Top Dead Center (TDC) and engine speed information to the ECU\
by counting the flywheel teeth as they pass during engine operation.
The flywheel has a large trigger tooth and notch located 12 small
teeth before each TDC position. See Fig. 2.
Fig. 2: Design of Speed Sensor
When a small tooth and notch pass the magnetic core of the
sensor, the concentration and collapse of the magnetic field created
induces a small voltage spike into the sensor pick-up coil windings.

BRAK E S YSTE M

1988 J e ep C hero ke e
1988 BRAKES
Jeep - Brake System
Cherokee, Comanche, Grand Wagoneer, Wagoneer, Wrangler
DESCRIPTION
DISC BRAKES
Floating caliper disc brake assembly uses a single piston
caliper which "floats" on 2 bolts. As brake pedal is depressed,
hydraulic pressure is passed through a proportioning valve to brake
caliper piston.
This force is transmitted to inboard brake pad, forcing it
against braking surface of rotor. Pressure then moves outer caliper
housing and pad inward on caliper mounting bolts, thus forcing outer
pad against outer braking surface of rotor.
DRUM BRAKES
Self-centering type system uses primary and secondary brake
shoes with cable operated automatic adjusters. Brake shoe anchor is
located at upper end of shoes above wheel cylinder. Single double
acting brake cylinder is used.
MASTER CYLINDER - EXCEPT GRAND WAGONEER
The Delco Quick Take-Up master cylinder is used with systems
utilizing low drag calipers. Master cylinder includes a quick take-up
valve which delivers a large volume of fluid, at low pressure, upon
initial brake application.
MASTER CYLINDER - GRAND WAGONEER
Bendix and Delco-Moraine tandem dual piston master cylinders
are single casting type with front and rear pistons and a separate
reservoir and outlet for each piston. Primary piston is operated by
push rod connected to brake pedal. Secondary piston is operated by
primary piston.
ADJUSTMENTS
NOTE: For Hub, Bearing and Axle Shaft Removal, Installation and
Adjustment information, see appropriate DRIVE AXLES article.
DISC BRAKE PADS
Automatic adjustment is provided by outward relocation of
piston as lining wears.
DRUM BRAKE SHOES
1) Rear brake shoes adjust automatically as brakes are
applied while vehicle is operated in reverse. Drive vehicle in reverse
applying brakes firmly 10-15 times, between each reverse brake
application, drive vehicle forward and press brakes firmly.
2) Manual adjustment is required if shoes have been removed

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.

Disassembly
Remove dust boots. Push pistons, piston cups and expander
spring out of bore. Discard cups. Clean all parts with brake solvent.
Inspect cylinder bore and piston for pitting, wear or damage. Replace
as necessary. Light scoring or pitting may be removed by honing.
Reassembly
1) Lubricate cylinder bore and internal components with brake
fluid. Do not lubricate dust boots. Position replacement piston cups
on spring expanders. Install assembled parts in cylinder bore.
2) Ensure expanders are seated in piston cups. Cups are to be
installed with lips facing each other. Install pistons with flat sides
facing interior of bore. Install dust boots.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS TABLE








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Application Ft. Lbs. (N.m)
Disc Brakes
Caliper Mounting Bolts ......................... 35 (47)
Bleeder Screw .................................. 12 (16)
Brake Line-to-Caliper .......................... 13 (18)
Drum Brakes
Wheel Cylinder Bolts ........................... 11 (15)
Bleeder Screw 1/4" ........................... 4-5 (5-7)
Bleeder Screw 3/8" ......................... 4-10 (5-14)
Brake Line ............................... 10-17 (14-23)
Backing Plate Bolt ....................... 30-40 (41-54)
Master Cylinder Retaining Nuts
Except Grand Wagoneer .......................... 20 (27)









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BRAKE SYSTEM SPECIFICATIONS
DISC BRAKE SPECIFICATIONS
DISC BRAKE SPECIFICATIONS TABLE








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Application In. (mm)
Cherokee, Comanche, Wagoneer & Wrangler
Disc Diameter ............................ 11.02 (279.9)
Lateral Runout ............................ 0.005 (0.13)
Parallelism ............................... 0.001 (0.03)
Original Thickness ......................... 0.88 (22.4)
Min. Refinish Thickness .................. 0.815 (20.70)
Discard Thickness ........................ 0.815 (20.70)
Grand Wagoneer
Disc Diameter ............................ 12.00 (304.8)
Lateral Runout ............................ 0.005 (0.13)
Parallelism ............................... 0.001 (0.03)
Original Thickness ................................. N/A
Min. Refinish Thickness .................. 1.215 (30.86)
Discard Thickness ........................ 1.215 (30.86)









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DRUM BRAKE SYSTEM SPECIFICATIONS
DRUM BRAKE SPECIFICATIONS TABLE

CLUTCH
Removal
Remove transmission assembly. Mark position of clutch cover
on flywheel for reassembly reference. Evenly loosen clutch cover bolts
one or 2 turns at a time until clutch cover spring tension is
released. Remove cover bolts, clutch cover, and disc. See Fig. 1.
Installation
1) Check all components for wear or damage and replace as
necessary. Using clutch alignment tool, align clutch disc and loosely
install clutch cover. Be sure marks made during removal are aligned.
2) To avoid warping clutch cover, tighten each cover bolt a
few turns at a time. To complete installation, reverse removal
procedure.
Fig. 1: Exploded View Of Cherokee, Comanche & Wagoneer Hydraulic
Clutch Assembly
Wrangler has a one-piece slave cylinder.
CLUTCH MASTER CYLINDER
Removal
1) Disconnect hydraulic line at master cylinder. Plug
openings to prevent dirt from entering system. Remove cotter pin and
washer holding cylinder push rod on clutch pedal.
2) Slide push rod off pedal pivot. Remove nuts attaching
clutch master cylinder to studs on dash panel and remove cylinder.
Installation
To install, reverse removal procedure. Bleed hydraulic
system.

bleeding. Refill clutch master cylinder to level mark on reservoir.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS TABLE








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Application Ft. Lbs. (N.m)
Cherokee, Comanche & Wagoneer
Bellhousing-to-Engine Bolts .................... 28 (38)
Clutch Cover Bolts ............................. 23 (31)
Crossmember-to-Sill Bolts ...................... 30 (41)
Flywheel Bolts
4-Cylinder .............................. ( 1) 50 (68)
6-Cylinder ............................ 61-75 (83-102)
Master Cylinder Attaching Nuts ................. 19 (26)
Rear Support-to-Engine Bolt .................... 33 (45)
Slave Cylinder-to-Clutch
Housing Bolts .................................. 16 (22)
Transmission Drain Plug ........................ 27 (37)
Wrangler
Bellhousing-to-Engine Bolts .................... 28 (38)
Clutch Cover Bolts
4-Cylinder .................................... 23 (31)
6-Cylinder .................................... 40 (54)
Crossmember-to-Sill Bolts ...................... 30 (41)
Master Cylinder Attaching Nuts ................. 19 (26)
Rear Support-to-Crossmember Bolts .............. 33 (45)
Transmission Drain Plug ........................ 27 (37)
( 1) - Plus additional 60 degrees turn after reaching
torque specification.









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