Bleeding the Rear Brakes

Brake Fluid Replacement - Routine Maintenance

Braking performance reduces as brake fluid ages, Repeated stops cause brake fluid to heat and cool rapidly reducing braking performance.

Brake fluid absorbs moisture over a period of time and becomes contaminated as it ages.

Therefore brake fluid should be replaced at specified intervals as instructed in the routine maintenance schedule, see Brake Fluid - Renew.

Brake Bleeding - Description

Brake Bleeding

When removing or replacing brake components and the brake line is opened air will enter as fluid escapes.

If the brake bleed procedure is not carried out air can become trapped in the brake fluid.

A consequence of air being trapped in the brake system is that the brake can feel soft/spongy and the performance of the brakes will be reduced.

notice
Always renew the brake fluid at the interval specified in the routine maintenance schedule.

Warning - General - Stabilise Motorcycle

warning
Make sure the motorcycle is stabilised and adequately supported.Do not support the motorcycle on any ancillary component, the exhaust system or any other non structural parts of the motorcycle frame.A correctly supported motorcycle will help prevent it from falling.An unstable motorcycle may fall resulting in motorcycle damage, serious injury or death.
warning
Brake fluid is hygroscopic which means it will absorb moisture from the air. Only use new DOT 4 brake fluid from a sealed container, do not mix different brands of brake fluid and never use brake fluid from an unsealed container or from one that has been previously opened.Any absorbed moisture will greatly reduce the boiling point of the brake fluid.Moisture in the braking system may a cause a reduction in braking efficiency leading to loss of motorcycle control and an accident.
warning
Do not allow dirt or debris to enter the braking system when adding brake fluid to the brake fluid reservoir Always maintain absolute cleanliness as this will adversely affect the brake fluid's properties.Contaminated brake fluid may cause a reduction in brake performance leading to loss of motorcycle control and an accident.
warning
During bleeding, do not allow the brake fluid level to fall below the lower level mark in the reservoir.If the fluid level is allowed to fall below this mark, air may enter the system and the sequence of bleeding must be repeated.Trapped air in the braking system may a cause a reduction in braking efficiency leading to loss of motorcycle control and an accident.
warning
Check for fluid leakage around brake fittings, seals and joints. Leaks around fittings and joints may allow air to enter the brake system.Air entering the braking system may a cause a reduction in braking efficiency leading to loss of motorcycle control and an accident.
caution
Do not attempt to maintain brake fluid pressure by securing the brake lever to the handlebar or the brake pedal using a band or strap.Banding or strapping the brake lever or pedal may deform the piston seals in the caliper.Lever or pedal travel that is increased or reduced may a cause a reduction in braking efficiency leading to loss of motorcycle control and an accident.
caution
To prevent paint damage, do not spill brake fluid onto any area of the bodywork.Close the brake reservoir and wash any spilled brake fluid immediately with warm soapy water. Spilled brake fluid, if left, will damage painted and plastic surfaces.
caution
Pressure applied to the brake lever or caliper pistons during the bleeding process must be applied and removed smoothly and slowly. It must take a minimum of five seconds between lever positions (from fully released to stop).Failure to follow these instructions can allow air to be drawn in to the system through the bleed screw threads.
notice
An additional technician is required to monitor the fluid level and operate the brake lever or pedal when bleeding the brakes.The bleed screws should only be opened by a small angle, just enough to allow system pressure to drop. When pulling the brake lever or pushing the caliper pistons in, some resistance should be felt indicating that the screw is not opened too much.

Rear Brake Bleed Procedure Table

The following table indicates the procedure to follow when carrying out repairs or replacement of the following brake components.

Rear Brake Bleed Procedure Table

When replacing/fitting the

Bleed the brakes as follows:

ABS Modulator

Brake Fluid Cap Removal

Back bleed front and rear master cylinders

Bleed brake caliper

Final bleed procedure

Brake caliper conditioning

Brake Fluid Cap Installation

Master Cylinder

Brake Fluid Cap Removal

Back bleed master cylinder

Final bleed procedure

Brake caliper conditioning

Brake Fluid Cap Installation

-

Brake Caliper

Brake Fluid Cap Removal

Bleed brake caliper

Final bleed procedure

Brake caliper conditioning

Brake Fluid Cap Installation

-

Brake Hose/Line(s)

Brake Fluid Cap Removal

Back bleed master cylinder

Bleed brake caliper

Final bleed procedure

Brake caliper conditioning

Brake Fluid Cap Installation

Brake Fluid Cap Removal

  1. Unscrew and remove the rear brake reservoir cover taking care not to spill any fluid.
  2. Carefully remove the diaphragm seal.
  3. Check the condition of the diaphragm seal. Replace if necessary.
    4. Rear brake reservoir, chrk_1

    1. Rear reservoir

    2. Rear reservoir upper level

    3. Rear reservoir lower level

Rear Brake Master Cylinder Back Bleed

Perform the following operations

Perform the following operations:

Rear Wheel - Remove L Series

    caution
    When disconnecting the brake hose from the master cylinder it is necessary to keep the open end of the hose above the height of the rear brake master cylinder.Allowing the brake hose to fall below the rear brake master cylinder height will allow an excessive amount of air to enter into the brake system. Trapped air may cause the brake lever to feel spongy and contribute to reduced braking efficiency.
    note
    Note the position of the rear brake caliper for installation.
  1. Remove the brake caliper and carrier assembly.
    2. Rear Caliper Align_1 (ckvh)

    1. Caliper carrier, wheel shown removed for clarity

    2. Swinging arm slot

    3. Caliper carrier groove

    warning
    Make sure no damage is made to the brake pad material when moving the brake pads.Allowing the brake pads to come into contact with each other or sharp objects may cause the material to crack or break.Damage to the brake pads may result in reduced braking efficiency leading to loss of motorcycle control and an accident.
  2. Using a suitable flat metal plate approximately 2 mm thick and 30 to 50 mm wide (for example a gasket scraper) between the brake pads, pump the rear brake pedal slowly until the plate is held by the brake pads. Do not allow the pistons to fall out.
  3. Being careful not to damage the brake pad material, use the metal plate against the brake pads to push the caliper pistons in evenly.
  4. Push the pistons into the caliper to apply pressure to the system.
  5. Position the rear brake caliper and carrier to the swinging arm as noted prior to removal. Align the groove in the carrier with the boss on the swinging arm.
    6. Rear Caliper Align_1 (ckvh)

    1. Caliper carrier, wheel shown removed for clarity

    2. Swinging arm slot

    3. Caliper carrier groove

Perform the following operations

Perform the following operations:

Rear Wheel - Install L Series

Rear Brake Caliper Bleed

  1. Remove the rubber cap from the caliper bleed screw.
  2. Attach a transparent tube to the bleed screw.
  3. Place the other end of the tube in a suitable container containing new brake fluid.
    4. Bleeding the Rear Brakes, (cbgk2)

    1. Bleed screw

    2. Spanner

    3. Bleed tube

    notice
    The bleed screw should only be opened by a small angle, just enough to allow system pressure to drop. When pulling the brake pedal or pushing the caliper pistons in, some resistance should be felt indicating that the screw is not opened too much.
  4. Slowly apply and slowly release pressure to the brake pedal five times, maintaining pressure on the final application.
  5. Open the bleed screw slightly to allow fluid to flow out but to still feel resistance in the brake pedal.
  6. Close the bleed screw.
  7. Slowly apply and slowly release pressure to the brake pedal five times, maintaining pressure on the final application.
  8. Open the bleed screw slightly to allow fluid to flow out but to still feel resistance in the brake pedal.
  9. Leave the bleed screw slightly open and slowly release the brake pedal.
  10. Slowly apply and slowly release pressure to the brake pedal five times.
  11. Close the bleed screw.
  12. Repeat steps 4 to 11 until no more air appears in the bleed tube/container.
  13. With the brake pedal still applied tighten the bleed screw to 6 Nm.
  14. Fill the reservoir to the upper level with new DOT 4 fluid.
  15. Remove the transparent bleed tube.

Rear Brake Final Bleed Procedure

  1. Repeat the bleed procedure as detailed in Rear Caliper Bleed .
  2. If brake pedal travel is unacceptably high, bleed the rear brake as detailed in Rear Master Cylinder Back Bleed.
  3. If brake pedal travel is acceptable, refit the rear brake reservoir cover.

Warning Brakes - Dangerous to operate with defective brakes

warning
It is dangerous to operate the motorcycle with defective brakes.The fault must be checked and rectified by a competent person with the specialist knowledge and technical understanding of motorcycles, such as an authorised Triumph dealer.Failure to follow the advice above may lead to loss of motorcycle control which could result in serious injury or death.

Brake Caliper Conditioning

  1. Using a suitable tool, push the rear brake caliper pistons 1-2 mm into the caliper body by forcing the brake pads apart.
    2. Rear Brake Back Bleed LG1 (ckwx)

    1. Brake pad

    2. Brake caliper

  2. Operate the brake pedal to pump the pistons back out until the brake pads come into contact with the brake disc.
  3. Repeat steps 1 and 2 on the caliper until the pistons have been pushed in and out three times.
  4. Slowly apply the rear brake pedal to the stop and maintain that pressure for approximately five seconds. Slowly release the pedal, and leave for 30 seconds. Repeat three times.

Brake Fluid Cap Installation

    caution
    To prevent paint damage, do not spill brake fluid onto any area of the bodywork.Close the brake reservoir and wash any spilled brake fluid immediately with warm soapy water. Spilled brake fluid, if left, will damage painted and plastic surfaces.
  1. Check the condition of the brake fluid cap sealing diaphragm. Replace the diaphragm if necessary.
  2. Refit the rear brake reservoir cap.
    3. Rear brake reservoir, chrk_1

    1. Rear reservoir

    2. Rear reservoir upper level

    3. Rear reservoir lower level