REMOVAL & INSTALLATION
The double pin Kelsey-Hayes calipers used on the Chrysler Corp. LH platform are mounted using bushings, sleeves and two through-bolts which thread directly into bosses on the steering knuckle. The calipers use two machined pads on the steering knuckles (suspension knuckle for the rear calipers) position and align the caliper fore and aft. The rear calipers are similar to the front calipers. The rear calipers bolt to an adapter and shield assembly mounted on the rear suspension knuckle of the vehicle. On both front and rear calipers, the guide pin bolts, sleeves and bushings control the float or the side to side movement of the caliper. These calipers are a one-piece casting with a single phenolic piston. Note that the pistons used in the front and rear calipers are different and must not be interchanged.
The brake calipers may be inspected while on the vehicle. Check for piston seal leaks (brake fluid in and around the boot area and inboard lining) and for any ruptures of the piston dust boot. If the boot is damaged or a fluid leak is visible, disassemble the caliper and install a new seal and boot. Replace the caliper pin bushings is dry or found to be brittle. To remove the brake calipers, use the following procedure.
- Disconnect the negative battery cable.
- Loosen the lug nuts on the front wheel being worked on.
- Raise and support the vehicle safely.
- Remove the appropriate wheel and tire assemblies.
- Remove the caliper guide pin bolts and remove the caliper assembly. If the caliper is not being removed from the vehicle as during brake pad renewal, simply hang the caliper with a piece of wire to take the weight off the brake hose. If the caliper is being removed for rebuild or replacement, continue to Step 6.
- Remove the bolt retaining the brake hose to the caliper. Be sure to plug the end of the brake hose or cover it with a plastic bag to prevent contamination from entering the hydraulic system. Remove the caliper from the vehicle.
Before installing the caliper assembly, be sure to clean the machined mounting surfaces of the steering knuckle of any grease or dirt.
- Reconnect the brake hose to the caliper, if removed, using new gasket.
- If new linings are being installed, the caliper pistons must be pushed back into their bore to accommodate the thickness of the new lining. Special tools are available for pushing the piston back although a large C-clamp can often be used. It is good practice to remove some (one-third to one-half) brake fluid from the master cylinder reservoir. This prevents overflow caused by brake fluid being forced through the lines as the piston is pushed back.
- Install the brake shoes into the caliper.
- Install the caliper to the steering knuckle in the correct position. Lubricate the machined areas that support the caliper with high-temperature grease.
- Install and tighten the caliper guide pin bolts. Use care not to cross the threads of the caliper pin bolts. Tighten the guide pin bolts to 17 ft. lbs. (22 Nm).
- Tighten the brake hose fittings to 35 ft. lbs. (48 Nm).
- Be sure to bleed the brake system.
- Install the wheels and hand-tighten the lug nuts.
- Lower the vehicle and tighten the wheel lug nuts in a star pattern sequence to 95 ft. lbs. (129 Nm).
- Before attempting to move the vehicle, pump the brake pedal to seat the pads against the rotors. Make sure the vehicle has a firm brake pedal. Check the level of the brake fluid and add DOT 3 brake fluid, if necessary.
- Road test the vehicle and make several stops to wear off any foreign material on the brakes and to seat the brake linings, if replaced.
See Figures 1, 2, 3, 4, 5 and 6
Use this service procedure as a guide for overhaul of the caliper assembly for all years/models. If in doubt about overhaul condition or service procedure REPLACE the complete assembly.
- Remove the caliper as previously outlined, leaving the brake line connected. Hang the assembly using a wire hook away from the rotor.
- Place a piece of wood between the piston and the caliper fingers.
- Carefully have a helper depress the brake pedal to hydraulically push the piston out of the bore. When the piston has passed out of the bore, fluid and pedal pressure will drop. As soon as pedal pressure drops, hold the pedal in position with the foot then devise a means to keep it there during work-this will minimize fluid loss and difficulty bleeding the system later.
- Disconnect the flexible brake line at the frame bracket and immediately plug the open end of the line. If the piston from the caliper on the opposite side of the car must now be removed, it can be removed in the same way. When the piston has been removed, disconnect and plug the other flexible line.
- Place the caliper in a vise which has soft jaws, clamping it as lightly as possible.
Excessive vise pressure will cause bore distortion and piston binding.
- Remove the dust boot and discard it.
- Work the piston seal out of its groove in the piston bore. Discard the old seal.
- Remove the bushings from the caliper by pressing them out, using a suitable tool. Discard the old bushings. If a Teflon® sleeve is used, discard this also.
- Clean all parts using alcohol and blow dry with compressed air.
Whenever a caliper has been disassembled, a new boot and seal must be installed.
- Inspect the piston bore for scoring or pitting. Bores with light scratches can be cleaned up. If the bore is scratched beyond repair, the caliper should be replaced.
- Dip the new piston seal in clean brake fluid and install it in the bore groove.
Never use an old piston seal.
- Coat the new piston with clean brake fluid, leaving a generous amount inside the boot.
- Position the dust boot over the piston.
- Install the piston into the bore, pushing it past the piston seal until it bottoms in the bore.
Force must be applied uniformly to avoid cocking the piston.
- Position the dust boot in the counterbore.
- Using tools C-4689 and C-4171 or their equivalents install the dust boot.
- Remove the Teflon® sleeves from the guide pin bushings before installing the bushings into the caliper. After the new bushings are installed in the caliper, reinstall the Teflon® sleeves into the bushings.
- Be sure the flanges extend over the caliper casting evenly on both sides.
- When reinstalling the calipers use new seal washers and tighten the brake hose connections to 24 ft. lbs. (33 Nm).
- Bleed the brake system. Pump the brake pedal several times to ensure that the brake pads seat against the rotor. The pedal must give resistance at the normal position before attempting to drive the car. Drive the car at moderate speeds in an isolated area in order to apply the brakes several times to test the system.