Removal
Caution! Damaged banjo bolt surfaces will leak when reassembled. Prevent damage to seating surfaces by carefully removing brake line components.
1. Remove right side cover and maxi-fuse. See 8.5 Maxi-fuse.
2. Remove radiator left side cover.
3. See Figure 2-49. With a suitable container under the master cylinder, remove the banjo bolt (1). Discard the two steel/rubber washers (7).
![](https://motoinstruction.ru/img/harley/2/111334.jpg)
Figure 2-49. Rear brake master cylinder & reservoir: 1. Banjo bolt; 2. Master cylinder; 3. Remote reservoir; 4. Clevis pin and brake pedal clevis; 5. Brake rod; 6. Jam nut; 7. Steel/rubber washers
4. Remove the cotter key from the clevis pin (4).
5. See Figure 2-50. Cover the outside face of clevis pin with cardboard and using a large pliers, squeeze the pin until the pin shoulder pops out of its interference fit with the clevis. Remove the clevis pin.
![](https://motoinstruction.ru/img/harley/2/111335.jpg)
Figure 2-50. Releasing clevis pin (brake pedal removed from motorcycle for clarity)
6. See Figure 2-49. Remove the brake rod (5) from the clevis.
7. Pull remote reservoir from slot on radiator cover.
8. Remove jam nut (6) to free master cylinder from mounting bracket.
9. Remove master cylinder with the remote reservoir.
Disassembly
PART NO. | SPECIALTY TOOL |
HD-41137 | Hose clamp pliers |
1. See Figure 2-51. Remove the reservoir cover (6) and gasket (7).
![](https://motoinstruction.ru/img/harley/2/111336.jpg)
Figure 2-51. Rear brake master cylinder/reservoir: 1. Clip; 2. Screw; 3. Hose; 4. Conduit; 5. Screw; 6. Reservoir cover; 7. Gasket; 8. Reservoir; 9. Clamp; 10. Jam nut; 11. Cartridge housing; 12. Service parts kit; 13. Push rod; 14. Brake pedal bushings; 15. Brake pedal; 16. Clevis; 17. Cotter pin; 18. Rod end; 19. Nut; 20. Retaining ring; 21. Washer; 22. Dust boot; 23. Brake return spring retainer; 24. Brake return spring; 25. Retaining ring; 26. Retaining ring; 27. Seal ring; 28. Banjo bolt; 29. Steel/rubber washers; 30. Frame clip; 31. Bolt; 32. Stoplamp switch; 33. Brake line
2. Over suitable container, separate and drain the reservoir (8) and hose (3).
3. Using HOSE CLAMP PLIERS (HD-41137), remove the hose clamps (9) from the remote reservoir hose (3).
4. Thoroughly clean exterior of master cylinder assembly with denatured alcohol.
Note. Measure and record the length of threads showing on the rod end.
- The master cylinder can be assembled to this dimension to return the brake pedal to its original operating position.
- Rod end thread engagement of the push rod should be at least 11.5 mm (0.450 in).
5. Turning push rod (13) with wrench, break jam nut (19) loose. Remove rod end (18) with jam nut (19).
6. Push on cartridge housing (11) to separate from cartridge. Use hand pressure only.
7. Stand master cylinder assembly upright on banjo sealing surface. Be sure to lay down a clean shop cloth to protect the sealing surface from damage.
Warning! Always wear proper eye protection when removing retaining rings. Use the correct retaining ring pliers. Verify that the tips of the pliers are not damaged or excessively worn. Slippage could propel the ring with force which could cause death or serious injury.
8. Push down on large flat washer (21) to compress spring (24).
9. While holding the spring (24) in a compressed state, remove the retaining ring (20). Carefully release spring tension.
10. Remove the large flat washer (21), dust boot (22), spring retainer (23), and spring (24).
11. Push on cartridge housing (11) to separate from cartridge. Use hand pressure only.
Warning! Always wear proper eye protection when removing retaining rings. Use the correct retaining ring pliers. Verify that the tips of the pliers are not damaged or excessively worn. Slippage could propel the ring with force which could cause death or serious injury.
12. See Figure 2-52. Push down on push rod to compress piston spring and remove retaining ring inside cartridge.
![](https://motoinstruction.ru/img/harley/2/111337.jpg)
Figure 2-52. Compressing piston spring
13. See Figure 2-51. Remove pushrod (13) and seal ring (27).
14. Remove piston and piston spring.
Warning! Always wear proper eye protection when removing retaining rings. Use the correct retaining ring pliers. Verify that the tips of the pliers are not damaged or excessively worn. Slippage could propel the ring with force which could cause death or serious injury.
15. Remove large retaining ring (25) from cartridge.
Warning! Always wear proper eye protection when removing retaining rings. Use the correct retaining ring pliers. Verify that the tips of the pliers are not damaged or excessively worn. Slippage could propel the ring with force which could cause death or serious injury.
Cleaning and inspection
Warning! Clean brake system components using denatured alcohol. Do not use mineral-base cleaning solvents, such as gasoline or paint thinner. Use of mineral-base solvents causes deterioration of rubber parts that continues after assembly. This may result in improper brake operation which could result in death or serious injury.
1. Clean all rubber parts using denatured alcohol. Check dust boot for cuts or tears. Replace as necessary.
2. Inspect threads on the cartridge body, push rod and brake rod. Replace if threads are damaged.
3. Inspect spring for cracks or broken coils. Replace as necessary.
4. Wipe bore of cartridge housing with DOT 5 SILICONE BRAKE FLUID.
5. Inspect reservoir cover gasket for cuts, tears or general deterioration. Replace as necessary.
Assembly
To rebuild rear brake master cylinder, use the components found in the SERVICE PARTS KIT No. 42383-87C.
PART NO. | SPECIALTY TOOL |
HD-41137 | Hose clamp pliers |
Warning! Always wear proper eye protection when removing retaining rings. Use the correct retaining ring pliers. Verify that the tips of the pliers are not damaged or excessively worn. Slippage could propel the ring with force which could cause death or serious injury.
1. See Figure 2-53. Lubricate new o-rings (1) with DOT 5 SILICONE BRAKE FLUID and carefully install in grooves on new cartridge (3).
![](https://motoinstruction.ru/img/harley/2/111338.jpg)
Figure 2-53. Master cylinder components: 1. O-ring; 2. Slot; 3. Cartridge; 4. Piston spring; 5. Primary cup; 6. Piston; 7. O-ring; 8. Drain hole; 9. Rod end; 10. Jam nut
2. Install new primary cup (5) with the flared end toward the threaded end of the cartridge and new o-ring (7) on new piston (6).
3. Slide new spring (4) into piston (6) and slide into cartridge (3).
Warning! Always wear proper eye protection when removing retaining rings. Use the correct retaining ring pliers. Verify that the tips of the pliers are not damaged or excessively worn. Slippage could propel the ring with force which could cause death or serious injury.
4. Lay down a clean shop cloth to protect the banjo sealing surface from damage. Stand master cylinder assembly upright on banjo sealing surface.
5. See Figure 2-51. Insert ball end of push rod (13) with seal ring (27) around rod into piston cup. Pushing down to compress spring, install small retaining ring (26) in groove of cartridge body bore. Verify that retaining ring is completely seated in groove capturing seal ring and that push rod rotates freely.
6. Install large retaining ring (25) in groove closest to push rod end of cartridge body.
7. Insert cartridge into cartridge housing (11).
8. See Figure 2-53. Verify that tab inside of housing mates to slot (2) on threaded end of cartridge (3).
9. See Figure 2-51. Install brake return spring (24), brake return spring retainer (23), boot (22), and large washer (21) over push rod (13).
10. Push down on large flat washer (21) to compress brake return spring. While holding the spring in a compressed state with brake return spring (24) seated on large retaining ring (25), install retaining ring (20) on push rod.
11. See Figure 2-53. Rotate boot so that drain hole (8) is at bottom. Bottom is side opposite tab in housing and mating slot in cartridge. Pull down dust boot to seat over lip on housing.
12. See Figure 2-51. With jam nut (19) in original location, thread in brake rod (18) until jam nut bottoms on the push rod (13).
Note. Normal brake pedal adjustment range is 18-22 mm (0.69-0.89 in.) from center of clevis to backside of jam nut. See HEAR BRAKE PEDAL in 1.8 BRAKES.
13. Tighten jam nut to push rod.
14. Using new clamps (9) and HOSE CLAMP PLIERS (Part No. HD-41137), install new hose (3) covered with conduit (4) connecting master cylinder to reservoir.
15. Replace cover (6) and gasket (7).
Installation
1. See Figure 2-49. Route remote reservoir (3) and hose behind rear brake pedal. Press reservoir mounting studs into slots on radiator cover.
2. Fit square on bottom of master cylinder cartridge housing (2) into square hole of mounting bracket.
3. See Figure 2-51. Install the clevis pin (16) through the brake pedal (15) clevis and master cylinder brake rod (18).
4. Cover the face of clevis pin (16) and clevis with cardboard. Holding the brake pedal firmly, tap on a rod to seat shoulder of clevis pin into clevis. Install new cotter pin (17).
5. Apply LOCTITE® 243 (blue) to threads of jam nut (10). Thread jam nut (10) on cartridge housing and tighten to 41-54 Nm (30-40 ft-lbs).
Note. To avoid leakage, verify that the banjo bolt, brake line fitting and master cylinder bore are completely clean.
6. Lubricate new steel/rubber washers (29) with DOT 5 SILICONE BRAKE FLUID. Position new steel/rubber washers on each side of brake line (33). Insert the banjo bolt (28) through washers and fitting. Tighten to 23-31 Nm (17-23 ft-lbs).
7. Stand the motorcycle upright so that the reservoir is in a level position. Clean and remove reservoir cover.
Warning! Direct contact of DOT 5 SILICONE BRAKE FLUID with eyes may cause eye irritation, swelling, and redness. Avoid eye contact. In case of eye contact flush with large amounts of water and get medical attention. Swallowing large amounts of DOT 5 SILICONE BRAKE FLUID may cause digestive discomfort. If swallowed, obtain medical attention. Use in well ventilated area. KEEP OUT OF REACH OF CHILDREN.
8. See Figure 2-54. Add DOT 5 SILICONE BRAKE FLUID to the master cylinder reservoir until the fluid level is 12.7 mm (1/2 in.) below top of reservoir and is visible in sight window at rear of reservoir. Use only DOT 5 SILICONE BRAKE FLUID from a sealed container.
![](https://motoinstruction.ru/img/harley/2/111339.jpg)
Figure 2-54. Rear brake reservoir sight window (removed from motorcycle)
Warning! Whenever the brake line is reconnected, BEFORE moving motorcycle, you must pump brake fluid until the pistons push the pads against the brake disc. If you don’t pump fluid pressure up again, the brakes will not be available to stop the motorcycle which could result in death or serious injury.
9. Bleed brake system. See 1.9 Bleeding brakes.
10. Install gasket and cover on master cylinder. Tighten cover screws to 0.7-0.9 Nm (6-8 in-lbs).
11. Replace radiator side cover.
12. Replace maxi-fuse and right side cover.
Warning! After completing repairs or bleeding the system, always test motorcycle brakes at low speed. If brakes are not operating properly or braking efficiency is poor, testing at high speeds could result in death or serious injury.
13. Test brake system.
- a. Turn ignition switch ON. Pump brake foot pedal to verify operation of brake lamp.
- b. Test ride motorcycle. If the brakes feel spongy, bleed the system again. See 1.9 Bleeding brakes.