# Calipers rebuild

Remove caliper

Remove brake pads, and peel back dust seal from piston.

Place a piece of wood , or other semi soft material in the caliper to prevent the piston travelling all the way out. Apply air pressure to the brake hose fitting and blow the piston out of the bore.

If piston is seized, fill recess created from removing seal, with WD-40 or some other penetrating oil and allow the caliper to sit for an hour or more. Once caliper has soaked in penetrating oil, use a large pair of pliers to press piston in , then air to move it out. Move piston in and out until it comes free. If necessary, reinstall the caliper without the inboard brake pad and , after bleeding caliper, alternate between stepping on brake pedal and pushing piston in with a pry bar or pliers.

With piston removed, carefully remove the fluid seal from the housing.

### Assembly

Inspect all surfaces for wear or corrosion. If any corrosion is found, the component should be replaced.

Lube piston and cylinder with ATE brake cylinder paste or equivalent.

Install new seal in housing and gently and evenly insert piston. Before piston is fully seated, install dust seal in groove of housing, then into groove on piston.

Check and , if necessary, replace the mounting bushings or plastic shims inside the bushings.

### Part numbers

Front caliper rebuild kit : 34 11 1 153 202
Rear caliper rebuild kit : 34 21 1 153 194

E30 M3 Repair Manual V2.7. Copyright ©1999-2001 Koala Motorsport & Brett Anderson