Disassembly and Assembly
CLEANING AND INSPECTIONCheck for brake fluid leaks in and around dust boot area and inboard brake pad, and for any ruptures, brittleness or damage to the piston dust boot. If the dust boot is damaged, or a fluid leak is visible, disassemble caliper assembly and install a new piston seal and dust boot, and piston if scored. Refer to Caliper Disassembly And Re-Assembly Procedures below.
Check the guide pin dust boots to determine if they are in good condition. Replace if they are damaged, dry, or found to be brittle. Refer to Guide Pin Bushing Service in Disc Brake System, Brake Caliper Service.
CALIPER GUIDE PIN BUSHING SERVICE
The double pin caliper uses a sealed for life bushing and sleeve assembly. If required this assembly can be serviced using the following procedure.
REMOVING CALIPER GUIDE PIN BUSHINGS
1. Remove caliper from brake rotor (See Brake Pad Removal). Hang caliper assembly on a wire hook away from the brake rotor.
Removing Inner Sleeve From Bushing:
2. Push out and then pull the steel sleeve from the inside of the bushing using your fingers as shown).
Removing Bushing From Caliper:
3. Using your fingers, collapse one side of the bushing. Then pull on the opposite side to remove the bushing from the brake caliper housing.
INSTALLING CALIPER GUIDE PIN BUSHINGS
Folded Caliper Guide Pin Bushing:
1. Fold the bushing in half lengthwise at the solid middle section of the bushing.
Installing Caliper Guide Pin Bushing:
2. Insert the folded bushing into the caliper housing. Do not use a sharp object to perform this step due to possible damage to the bushing.
Bushing Correctly Installed In Caliper:
3. Unfold the bushing using your fingers or a wooden dowel until the bushing is fully seated into the caliper housing. Flanges should be seated evenly on both sides of the bushing hole.
4. Lubricate the inside surfaces of the bushing using Mopar, Silicone Dielectric Compound or an equivalent.
Fig 7 Installing Caliper Sleeves:
5. Install guide pin sleeve into one end of bushing until seal area of bushing is past seal groove in sleeve.
6. Holding convoluted boot end of bushing with one hand, push steel sleeve bushing through boot until one end of bushing is fully seated into seal groove on one end of sleeve.
Fig 8 Installed Caliper Bushing Sleeve:
7. Holding sleeve in place, work other end of bushing over end of sleeve and into the seal grove on sleeve. Be sure other end of bushing did not come out of seal grove in sleeve.
8. When the sleeve is seated properly into the bushing, the sealed for life sleeve/bushing can be held between your fingers and easily slid back and forth without the bushing unseating from the sleeve groove.
CALIPER DISASSEMBLY
WARNING: UNDER NO CONDITION SHOULD AIR PRESSURE EVER BE USED TO REMOVE A PISTON FROM A CALIPER BORE. PERSONAL INJURY COULD RESULT FROM SUCH A PRACTICE.
1. Remove caliper from brake rotor (See Brake Shoe Removal). Hang assembly on a wire hook away from rotor, so hydraulic fluid cannot get on rotor. Place a small piece of wood between the piston and caliper fingers.
2. Carefully depress brake pedal to hydraulically push piston out of bore. Then apply and hold down the brake pedal to any position beyond the first inch of pedal travel. This will prevent loss of brake fluid from the master cylinder.
3. If both front caliper pistons are to be removed, disconnect brake tube at flexible brake hose at frame rail. Plug brake tube and remove piston from opposite caliper using the same process as above for the first piston removal.
4. Disconnect the brake fluid flex hose from the caliper assembly.
CAUTION: Do not use excessive force when clamping caliper in vise. Excessive vise pressure will cause bore distortion and binding of piston.
5. To disassemble caliper, mount in a vise equipped with protective jaws.
6. Remove guide pin sleeves and guide pin bushings.
Fig. 10 Dust Boot Removal:
7. Remove the piston dust boot from the caliper and discard.
Removing Piston Seal From Caliper:
8. Using a soft tool, such as a plastic trim stick, work piston seal out of its groove in caliper piston bore. Discard old seal. Do not use a screw driver or other metal tool for this operation, because of the possibility of scratching piston bore or burring edges of seal groove.
9. Clean all parts using alcohol or a suitable solvent and wipe dry using only a lint free cloth. No lint residue can remain in caliper bore. Clean out all drilled passages and bores. Whenever a caliper has been disassembled, a new boot and seal must be installed at assembly.
Honing Brake Caliper Piston Bore:
10. Inspect the piston bore for scoring or pitting. Bores that show light scratches or corrosion can usually be cleared of the light scratches or corrosion using crocus cloth. Bores that have deep scratches or scoring should be honed. Use Caliper Hone, Special Tool C-4095, or equivalent providing the diameter of the bore is not increased more than 0.0254 mm (0.001 inch) .
11. If the bore does not clean up within this specification, a new caliper housing should be installed. Install a new piston if the old one is pitted or scored.
NOTE: When using Caliper Honing Tool, Special Tool C-4095, coat the stones and bore with brake fluid. After honing the bore, carefully clean the seal and boot grooves with a stiff non-metallic rotary brush.
NOTE: Use extreme care in cleaning the caliper after honing. Remove all dirt and grit by flushing the caliper with brake fluid; wipe dry with a clean, lint free cloth and then clean a second time.
CAUTION: When inspecting caliper piston, do not use anything but solvents to clean piston surface. If surface of piston cannot be cleaned using only solvents, piston must be replaced.
12. Inspect caliper piston for pitting, scratches, or any physical damage. Replace piston if there is evidence of scratches, pitting or physical damage.
CALIPER ASSEMBLY
CAUTION: Excessive vise pressure will cause bore distortion and binding of piston.
1. Clamp caliper in a vise (with protective caps installed on jaws of vise).
Installing New Piston Seal In Caliper:
2. Dip new piston seal in clean brake fluid and install in the groove of the caliper bore. Seal should be positioned at one area in groove and gently worked around the groove , using only your fingers until properly seated. NEVER USE AN OLD PISTON SEAL. Be sure that fingers are clean and seal is not twisted or rolled.
3. Coat new piston boot with clean brake fluid leaving a generous amount inside boot.
4. Position dust boot over piston after coating with brake fluid.
CAUTION: Force must be applied to the piston uniformly to avoid cocking and binding of the piston in the bore of the caliper.
Installing Piston Into Caliper Bore:
5. Install piston into caliper bore pushing it past the piston seal until it bottoms in the caliper bore.
6. Position dust boot into the counterbore of the caliper assembly piston bore.
7. Using a hammer and Installer Piston Caliper Boot, Special Tool C-4689 and Handle, Special Tool C-4171, drive boot into counterbore of the caliper.
8. Install guide pin sleeves and bushings.
9. Install brake pads.
10. Before installing caliper assembly on vehicle, inspect brake rotor. If any conditions as described in Checking Brake Rotor for Runout and Thickness are present the rotor, must be replaced or refaced. If the rotor does not require any servicing, install caliper assembly.
11. Install brake hose onto caliper using banjo bolt. Torque the brake hose to caliper assembly banjo bolt to 33 Nm (24 ft. lbs.). New seal washers MUST always be used when installing brake hose to caliper.
12. Bleed the brake system.