FN 3 Brake Calipers

FN 3 front brake calipers, servicing

Note:
- Install all parts supplied in repair kit.
- New brake calipers are filled with brake fluid and are pre-bled.
- Apply thin coat of lubricant G 052 150 A2 to brake cylinders, pistons and seals.

1. Protective seal
2. Bleed valve
- Apply thin coat of assembly lubricant G 052 150 A2 to threads before screwing in
3. Cap
- Insert in mounting bushing
4. Guide pins, 28 Nm (21 ft. lbs.)
5. Mounting bushing
- Insert into brake caliper housing
6. Brake caliper housing
7. Brake carrier
- Install on brake caliper housing
8. Retaining spring
- Insert with both ends in the holes in brake caliper housing
9. Seal
- Removing and installing
10. Piston
- Removing and installing
- Apply thin coat of assembly lubricant G 052 150 A2 to piston before inserting
- Piston diameter 54 mm (2.126 inch)
11. Protective seal
- Do not damage when inserting piston

Front caliper piston, removing and installing

Special tools and equipment





- 3409 Wedge
- Piston resetting tool

Removing





- Force piston out of brake caliper housing using compressed air.

Note: Place a piece of wood in the recess to prevent damaging the piston.





- Remove seal using wedge 3409.

Note: When removing the piston seal make sure that the cylinder bore is not damaged.

Installing
- The surface of the piston and seal must only be cleaned with methylated spirits and then dried.
- Thinly coat piston and seal with assembly lubricant G 052 150 A2 before inserting.
- Insert oil seal in brake caliper housing.





- Place protective seal with the outer sealing lip on the piston.





- Using wedge 3409, insert the inner sealing lip into the grove in the cylinder.

Note: Hold piston in front of caliper housing.





- Press piston into the brake caliper housing using piston resetting tool.

Note: The protective seal outer sealing lip must slip into the piston groove.