Jeep Cherokee (XJ): Disassembly and assembly

Master cylinder reservoir

REMOVAL

(1) Remove reservoir cap and empty fluid into drain container.

(2) Remove pins that retain reservoir to master cylinder. Use hammer and pin punch to remove pins (Fig. 40).

Fig. 40 Reservoir Retaining Pins

1 - PIN PUNCH
2 - RESERVOIR
3 - BODY
4 - ROLL PINS

(3) Clamp cylinder body in vise with brass protective jaws.

(4) Loosen reservoir from grommets with pry tool (Fig. 41).

Fig. 41 Loosening Reservoir

1 - PRYTOOL
2 - RESERVOIR
3 - GROMMET
4 - MASTER CYLINDER BODY

(5) Remove reservoir by rocking it to one side and pulling free of grommets (Fig. 42).

Fig. 42 Reservoir Removal

1 - RESERVOIR
2 - GROMMETS

(6) Remove old grommets from cylinder body (Fig.

43).

INSTALLATION

CAUTION: Do not use any type of tool to install the grommets. Tools may cut, or tear the grommets creating a leak problem after installation. Install the grommets using finger pressure only.

Fig. 43 Grommet Removal

1 - MASTER CYLINDER BODY
2 - GROMMETS

(1) Lubricate new grommets with clean brake fluid and Install new grommets in cylinder body (Fig. 44).

Use finger pressure to install and seat grommets.

Fig. 44 Grommet Installation

1 - WORK NEW GROMMETS INTO PLACE USING FINGER PRESSURE ONLY

(2) Start reservoir in grommets. Then rock reservoir back and forth while pressing downward to seat it in grommets.

(3) Install pins that retain reservoir to cylinder body.

(4) Fill and bleed master cylinder on bench before installation in vehicle.

Disc brake caliper

DISASSEMBLY

(1) Remove brake shoes from caliper.

(2) Drain brake fluid out of caliper.

(3) Take a piece of wood and pad it with one-inch thickness of shop towels. Place this piece in the outboard shoe side of the caliper in front of the piston.

This will cushion and protect caliper piston during removal (Fig. 45).

Fig. 45 Padding Caliper Interior

1 - SHOP TOWELS OR CLOTHS
2 - CALIPER

(4) Remove caliper piston with short bursts of low pressure compressed air. Direct air through fluid inlet port and ease piston out of bore (Fig. 46).

CAUTION: Do not blow the piston out of the bore with sustained air pressure. This could result in a cracked piston. Use only enough air pressure to ease the piston out.

WARNING: NEVER ATTEMPT TO CATCH THE PISTON AS IT LEAVES THE BORE. THIS MAY RESULT IN PERSONAL INJURY.

(5) Remove caliper piston dust boot with suitable pry tool (Fig. 47).

(6) Remove caliper piston seal with wood or plastic tool (Fig. 48). Do not use metal tools as they will scratch piston bore.

(7) Remove caliper mounting bolt bushings and boots (Fig. 49).

ASSEMBLY

CAUTION: Dirt, oil, and solvents can damage caliper seals. Insure assembly area is clean and dry.

(1) Lubricate caliper piston bore, new piston seal and piston with clean brake fluid.

(2) Lubricate caliper bushings and interior of bushing boots with silicone grease.

(3) Install bushing boots in caliper, then insert bushing into boot and push bushing into place (Fig.

50).

Fig. 46 Caliper Piston Removal

1 - AIR GUN
2 - CALIPER PISTON
3 - PADDING MATERIAL

Fig. 47 Caliper Piston Dust Boot Removal

1 - COLLAPSE BOOT WITH PUNCH OR SCREWDRIVER
2 - PISTON DUST BOOT

(4) Install new piston seal into seal groove with finger (Fig. 51).

(5) Install new dust boot on caliper piston and seat boot in piston groove (Fig. 52).

(6) Press piston into caliper bore by hand, use a turn and push motion to work piston into seal (Fig.

53).

(7) Press caliper piston to bottom of bore.

Fig. 48 Piston Seal Removal

1 - REMOVE SEAL WITH WOOD PENCIL OR SIMILAR TOOL
2 - PISTON SEAL

Fig. 49 Mounting Bolt Bushing And Boot

1 - CALIPER SLIDE BUSHING
2 - BOOT

Fig. 50 Bushings And Boots Installation

1 - BUSHING
2 - BOOT

Fig. 51 Piston Seal Installation

1 - SEAL GROOVE
2 - PISTON SEAL

Fig. 52 Dust Boot On Piston

1 - PISTON
2 - DUST BOOT

Fig. 53 Caliper Piston Installation

1 - PISTON
2 - BOOT

(8) Seat dust boot in caliper with Installer Tool C-4842 and Tool Handle C-4171 (Fig. 54).

Fig. 54 Piston Dust Boot Installation

1 - HANDLE C-4171
2 - INSTALLER C-4842
3 - DUST BOOT

(9) Replace caliper bleed screw if removed.

Wheel cylinder

DISASSEMBLY

(1) Remove push rods and boots (Fig. 55).

(2) Press pistons, cups and spring and expander out of cylinder bore.

(3) Remove bleed screw.

ASSEMBLY

(1) Lubricate wheel cylinder bore, pistons, piston cups and spring and expander with clean brake fluid.

(2) Install first piston in cylinder bore. Then install first cup in bore and against piston. Be sure lip of piston cup is facing inward (toward spring and expander) and flat side is against piston.

(3) Install spring and expander followed by remaining piston cup and piston.

(4) Install boots on each end of cylinder and insert push rods in boots.

(5) Install cylinder bleed screw.

Fig. 55 Wheel Cylinder Components-Typical

1 - SPRING
2 - CYLINDER
3 - PISTON CLIP
4 - BOOT
5 - PUSH ROD
6 - PISTON
7 - BLEED SCREW
8 - CUP EXPANDERS