Front Calipers

Brake caliper front, overhaul
Special tools: 115 8147, 981 4071
Preparations
^ Remove wheel.

Draining brake fluid
^ Clean brake caliper carefully.
^ Remove protective cap from bleed nipple and open nipple.





^ Lock pedal in depressed position with a pedal jack.
^ Collect emerging brake fluid.
^ Undo brake hose (1/2 turn).

Removing brake caliper and brake pads





^ Undo brake hose (1/2 turn).
^ Remove retaining spring (3) carefully to avoid deforming it.
^ Remove protective caps (1) from the two locating pins (2)
^ Remove locating pins, using 7 mm (0.276") hexagonal socket.
^ Remove brake caliper carefully from mounting to avoid damaging brake hose.
^ Remove brake pads.

Removing brake hose
^ Unscrew brake caliper from brake hose.
^ Drain remaining brake fluid.

Dismantling brake caliper

Warning: Take care to avoid getting fingers caught when piston is pushed out.





^ Put a block of wood in front of piston. Push piston out carefully using compressed air.





^ Remove dirt guard (3).
^ Remove O-ring (4). Use weatherstrip tool 981 4071 or similar so as not to damage edges of groove.
^ Remove rubber bushings (7) and bleed nipple (5).

Cleaning and inspection
^ Clean components in T-spirit. Check for wear, damage, cracks and rust. Replace components if necessary.
^ Always replace O-ring and dirt guard during overhaul. Take particular care to clean ducts and grooves for O- ring and dirt guard.
^ If cylinder is badly marked, scratched etc., replace complete caliper.
^ Remove minor rust deposits with fine sandpaper.

Assembling brake caliper





^ Blow ducts clean with compressed air.
^ Coat cylinder lining, piston (2) and new O-ring (4) with brake fluid.
^ Install lubricated O-ring (4) in groove in cylinder. Install dirt guard in end of piston (see illustration).





^ Install dirt guard in groove inside cylinder and push piston in carefully.
^ Check that dirt guard slots into its groove in the piston.





^ Check that dirt guard is in position properly.
^ Install bleed nipple (5), tighten to 9 Nm (7 ft. lbs.).

Finishing








^ Install rubber bushings in brake caliper.
^ Screw brake caliper onto hose by hand.
^ Hang brake caliper up on a steel wire on front spring to avoid damaging hose.
^ Go to Front brake pads, replacement