Overhaul

Disassembly

When disassembling the caliper, do not separate the caliper halves. The bolts attaching the caliper halves are tightened to a specific torque by the manufacturer.
1. Remove caliper from brake disc.
2. Remove brake pads from brake caliper assembly.
3. Using a suitable screwdriver, force dust cap from caliper housing.
4. Using suitable pliers, hold one caliper piston in.
5. Using compressed air, force the other piston out from caliper. When using compressed air, do not exceed 7 psi (.5 bars). If the caliper pistons are frozen in their bores, replace caliper as required.
6. Using a suitable tool, remove caliper piston seal from caliper cylinder groove.

Inspection

1. Push heat shield away from piston.
2. Using a soft brass wire brush or a rough cleaning cloth, remove deposits from piston. Do not polish piston with emery cloth. Replace piston, if chrome surface on piston is damaged.
3. Check caliper cylinder bores for wear and/or damage. Replace complete caliper assembly if caliper bores are scored or rusted. Remove small, minor rust spots with the caliper bore with polishing cloth. Remove heavier rust spots in front of piston seal groove with fine emery paper (380 to 500 grain).

Assembly

1. Coat new piston seal slightly with clean ATE brake cylinder paste and insert seal into caliper cylinder groove. When assembling Bendix type calipers, ensure a tight and correct seat of the pressing on seal ring.

Fig. 7 Piston identification, Bendix (left) & Teves (right):

2. Insert piston into caliper bore, then check position of piston in caliper. Two piston versions are used, Teves and Bendix. Ensure the correct one is installed, Fig. 7.
3. Using suitable pliers, move piston into correct position (flush with caliper). Install piston with elevation (marked black) on piston is pointed downward. While braking, this elevation will cause a one-sided contact of brake pads. This will reduce brake squealing.
4. On Teves type calipers, mount dust cap onto piston, and position against caliper collar. Install discs. Install heat shield into piston with shield recess installed accurately into piston elevation. Using a suitable press, insert spacer into caliper and press heat shield into piston. The elevation on piston should project approximately .0039 inch (.1 mm) beyond heat shield. Heat shield for the inner and outer piston are different. Do not interchange shields.
5. On Bendix type calipers, press heat shield onto piston according to piston position. The elevation of the piston should project approximately .0039 inch (.1 mm) beyond heat shield.
6. Place dust cap onto piston. Using a suitable tool, mount dust cap onto caliper collar. Push piston completely back until dust cap is completely seated onto piston collar.
7. Install brake pads onto caliper.
8. Install caliper onto disc rotor.