See Figures 1, 2, 3 and 4
We recommend replacement of the disc brake calipers in axle sets for added safety and reliability
- Raise and safely support the front of the vehicle on jackstands. Set the parking brake and block the rear wheels.
- Siphon a sufficient quantity of brake fluid from the master cylinder reservoir in order the brake fluid from overflowing when removing or installing the calipers. This is necessary as the piston must be forced into the cylinder bore to provide sufficient clearance to install the caliper.
Disassemble brakes one wheel at a time. This will prevent parts confusion and also prevent the opposite caliper piston from popping out during installation
- Disconnect the hose union at the caliper. Use a pan to catch any spilled fluid and immediately plug the disconnected hose.
- Remove the two caliper mounting bolts or guide plates, then remove the caliper from the mounting bracket.
See Figures 5 through 12
- On some early models you must first remove the two bridge bolts in order to split the caliper halves.
- Carefully remove the dust boot from around the cylinder bore.
- Apply compressed air to the brake line union to force the piston out of its bore. Place a rag or block of wood to protect the piston. Be careful, the piston may come out forcefully.
- Remove the seal from the piston. Check the piston and cylinder bore for wear and/or corrosion. Replace components as necessary.
- Coat all components with clean brake fluid.
- Install the seal and piston in the cylinder bore, after coating them with the rubber lubricant supplied in the rebuilding kit. Seat the piston in the bore with your fingers.
- Fit the boot into the groove in the cylinder bore.
- Install the caliper cylinder assembly.
- Use a caliper compressor, a C-clamp or large pair of pliers to slowly press the caliper piston back into the caliper.
- Install the caliper assembly to the mounting plate. Before installing the retaining bolts or guide plates, apply a thin, even coating of anti-seize compound to the threads and slide surfaces. Don't use grease or spray lubricants; they will not hold up under the extreme temperatures generated by the brakes. Tighten the bolts.
- Install the brake hose to the caliper. Always use a new gasket and tighten the union to about 17 ft. lbs. (23 Nm).
- Bleed the brake system.
- Remove the 2 lugs holding the disc in place and install the wheel.
- Lower the vehicle to the ground. Check the level of the brake fluid in the master cylinder reservoir; it should be at least to the middle of the reservoir.
If a firm pedal cannot be obtained, bleed and adjust the brake system. Do not attempt to move the vehicle until a firm pedal is obtained