Brake Bleeding: Service and Repair

Brake System Bleeding

WARNING: If any components upstream of the Hydraulic Control Unit (HCU), including the HCU itself are replaced, the brake system must be bled using Land Rover approved diagnostic equipment. This will ensure that all air is expelled from the new component(s).

NOTE:
The following procedure covers bleeding the brake system if components down stream of the HCU have been replaced. Where only the primary or secondary brake circuits have been disturbed in isolation, it should only be necessary to bleed that circuit. Partial bleeding of the hydraulic system is only permissible if a brake tube or hose has been disconnected with only minimal loss of fluid.

WARNING: Do not work on or under a vehicle supported only by a jack. Always support the vehicle on safety stands.
1 Raise and support the vehicle.
2 Check that the brake fluid lines are secure and that there are no signs of a brake fluid leak. If a brake fluid leak is detected, investigate and rectify the cause of the leak before bleeding the brakes.
For additional information, refer to Brake System Testing and Inspection
3 Pump the brake pedal until the brake vacuum assistance is exhausted.





WARNING: Do not allow dirt or foreign liquids to enter the reservoir. Use only new brake fluid of the correct specification from airtight containers. Do not mix brands of brake fluid as they may not be compatible.

CAUTION: Brake fluid will damage paint finished surfaces. If spilled, immediately remove the fluid and clean the area with water.
4 Remove the brake fluid reservoir cap.




5 Fill the brake fluid reservoir to the MAX mark.
6 Install the bleed tube to the brake caliper bleed screw and immerse the free end of the bleed tube in a bleed jar containing a small quantity of approved brake fluid.




Starting at the brake caliper furthest away from the brake master cylinder, loosen the bleed screw by one-half to three-quarters of a turn.

CAUTION: The brake fluid reservoir must remain full with new, clean brake fluid at all times during bleeding.
7 With assistance, depress the brake pedal steadily through its full stroke and allow it to return to the rest position. Repeat the procedure until brake fluid, clean and air-free flows into the bleed jar.
8 When brake fluid, clean and air-free flows into the bleed jar, depress and hold the brake pedal down.

CAUTION: Make sure the bleed screw cap is installed after bleeding. This will prevent corrosion to the bleed screw.
9 With the brake pedal fully depressed, tighten the bleed screw.
Torque to: 10 Nm





10 Fill the brake fluid reservoir to the MAX mark.

WARNING: Braking efficiency may be seriously impaired if an incorrect bleed sequence is used.

11 Repeat the brake bleeding procedure for each brake caliper, following the above sequence.

12 Fill the brake fluid reservoir to the MAX mark.

13 Apply the brakes and check for leaks.

14 Install the brake fluid reservoir cap.

15 Install the fluid reservoir access panel.