REMOVAL & INSTALLATION
See Figures 1 and 2
- Raise and safely support the front of the vehicle on jackstands. Set the parking brake and block the rear wheels.
- Siphon a sufficient amount of brake fluid from the master cylinder reservoir to prevent the brake fluid from overflowing when removing or installing the caliper. This is necessary as the piston must be forced into the cylinder bore to provide clearance to install the caliper.
- Remove the wheel.
Disassemble brakes one wheel at a time. This will prevent parts confusion and also prevent the opposite piston from popping out during installation.
- Disconnect the brake line at the clip on the strut and disconnect the hose union at the caliper. Use a pan to catch any spilled fluid and immediately plug the hose end.
- Remove the two caliper mounting bolts and then remove the caliper from the mounting bracket. Alternatively, remove the two bolts (screwed directly into the backing plate) which fasten the caliper support to the backing plate, and remove the entire assembly. Remove the brake pads and clips from the support as described above. Remove the lockpin (lower) and guide pin (upper) from the caliper support, and remove the caliper from the support.
- Use a caliper compressor, a C-clamp or a large pair of pliers to slowly press the caliper piston back into the caliper.
- If the mounting plate was removed from the backing plate, reinstall it and coat the bolts with an anti-seize compound. Tighten the bolts to 66 ft. lbs. (90 Nm).
- Install the pads onto the mount and install the caliper. Make sure the slide bushings and bolts are clean and properly lubricated. Do not use regular grease or spray lubricants; they cannot withstand the extreme heat generated by the brakes. Tighten the upper and lower bolts to 23-30 ft. lbs. (32-42 Nm).
- Connect the fluid hose to the caliper and then to the hard line at the body. Tighten each fitting to 12 ft. lbs. (17 Nm) and make sure the hose is correctly routed and not kinked. Remember to install any clips or retainers holding the line.
- Refill the master cylinder reservoir to the MAX line. Bleed the brake system. Keep a close eye on the reservoir, maintaining its level at at least half during the bleeding. Since the caliper was emptied, a fair amount of brake fluid may need to be added.
- Reinstall the wheel and lower the vehicle to the ground.
- Check the level in the fluid reservoir and top it off as needed. Before driving the car, start the engine and operate the brake pedal several times to check the feel and engagement point of the brakes.
To overhaul the brake calipers, you must have a controlled source of compressed air to force the pistons out. You should also have a generous supply of clean brake fluid or commercial brake cleaning spray to clean parts.
- Drain the remaining fluid from the caliper.
- Carefully remove the dust boot from around the piston by prying the boot ring out of its groove. Remove the piston and piston boot by applying compressed air through the brake hose fitting hole.
- Remove the seal from the inside of the caliper bore. Clean the caliper bore with brake cleaner, alcohol or brake fluid.
- Check all the parts for wear, deterioration, cracking or other abnormal conditions. Corrosion, generally caused by water in the system, will appear as white deposits on the metal, similar to what may be found on an old aluminum storm door around the house. Pay close attention to the condition of the inside of the caliper bore and the outside of the piston. Any sign of corrosion or scoring requires new parts; do not attempt to clean or resurface either face if there is damage present.
- The caliper overhaul kit will, at the minimum, contain new seals and dust boots. A good kit will contain a new piston as well, but you may have to buy the piston separately. Any time the caliper is disassembled, a new piston is highly recommended in addition to the seals.
- Clean all the components to be reused with a brake cleaner, alcohol or clean brake fluid and dry them thoroughly. Take any steps necessary to eliminate moisture or water vapor from the parts.
- Coat all the caliper components with fresh brake fluid from an unopened can.
Some kits come with special assembly lubricants for the piston seals and slides or guidepins. Use these lubricants according to the directions within the kit.
- Install the piston seal and piston into the caliper bore. This is an exacting job; the clearances are very small. Make sure the seal is seated in its groove and that the piston is not cocked when inserted into the bore.
- Install the new dust boot and new boot ring.
- Install the slide bushings and rubber boots onto the caliper if they were removed during disassembly.
- The guide and lockpin sleeves should be coated inside with the grease supplied with the rebuilding kit, and boots should all be replaced. Also coat the lips of the boots and the surface of the caliper which bears (and turns) against the caliper support with grease.
Two kinds of grease may be packed in a rebuilding kit; use the grease recommended for use with the guide and lockpins. On all the truck systems, coat the sliding parts of the caliper body and the sleeves with the grease specified.
- Install the brake caliper to the wheel assembly.