Disassembly and assembly of the front wheel brake mechanism (BMW 3 Series E21)

Disassembly

Remove the brake pads and caliper.

Remove the retaining rings and protective caps from the cylinders and pistons.

Lock the piston with pliers 34 1 050.

By forcing a stream of compressed air through the fluid inlet, push the piston out of the cylinder. To avoid damaging the piston on the surface of the caliper when pushing it out, place a wooden pad under the piston.

Close the cylinder hole with a plug and push the piston out of the other cylinder, proceeding as described above.

Carefully remove the piston seal rings from the cylinders.

Assembly

Carefully check the technical condition of the brake mechanism parts.

Lubricate the sealing rings, pistons and cylinder bores with a thin layer of brake cylinder paste.

Reinstall the O-rings and pistons.

Lubricate the inside surface of the protective caps with a thin layer of brake cylinder paste.

Place the protective caps and install the retaining rings.

Replace the brake pads, making sure the pistons are positioned at a 20° angle.

After installing the brake mechanism, fill the fluid into the hydraulic drive reservoir and bleed the hydraulic drive system.

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