AP System
BRAKE SYSTEM BLEEDINGThe hydraulic system comprises two completely independent sections. The rear calipers and the lower pistons in the front calipers form the secondary section, while the upper pistons in the front calipers form the primary section. The following procedure covers bleeding the complete system, but it is permissible to bleed one section only if disconnections are limited to that section.
Bleeding will be assisted if the engine is run or a vacuum supply is connected to the servo.
CAUTION: If the engine is running during the brake bleeding process ensure that neutral gear is selected and that the parking brake is applied.
When bleeding any part of the secondary section, almost full brake pedal travel is available. When bleeding the primary section only, brake pedal travel will be restricted to approximately half.
CAUTION: Before commencing to bleed the system it is necessary to loosen off the brake failure warning switch to prevent the shuttle valve damaging the switch unit. This is done by the following steps:
1. Disconnect the leads from the switch.
Brake Switch:
2. Unscrew the switch and insert the C-washer between the switch and master cylinder before depressing the brake pedal.
3. After completion of bleeding, remove the C-washer and screw in the switch and tighten to 1.4-1.7 Nm (1-1.3 ft lb).
NOTE: When bleeding the system commence with the caliper furthest from the master cylinder and bleed from the screw on the same side as the fluid inlet pipes, then close the screw and bleed from the screw on the opposite side of the same caliper. Tighten the bleed screws to 9-11 Nm (80-100 in lb).
Bleeding
1. Fill the fluid reservoir with the correct fluid.
NOTE: The correct fluid level must be maintained throughout the procedure of bleeding
Connecting Bleed Hose:
2. Connect a bleed hose to the bleed screw on the rear caliper furthest from the master cylinder.
3. Submerge the free end of the bleed hose in a container of clean brake fluid.
4. Loosen the bleed screw.
5. Operate the brake pedal fully and allow to return.
NOTE: Allow at least five seconds to elapse with the foot right off the pedal to ensure that the pistons fully return before operating the pedal again.
6. Repeat 5 until fluid clear of air bubbles appears in the container, then keeping the pedal fully depressed, tighten the bleed screw.
7. Remove the bleed hose and replace the dust cap on the bleed screw.
8. Repeat 1 to 7 for the other rear caliper.
9. Remove the front wheel on the side furthest from the master cylinder.
Bleeder Fittings:
10. Connect a bleed hose to the primary bleed screw on the front caliper furthest from the master cylinder.
11. Connect a bleed hose to the secondary bleed screw on the same side of the caliper as the primary screw.
12. Repeat 3 to 7 for the front caliper, bleeding from the two screws simultaneously.
13. Connect a bleed hose to the other screw on the front caliper furthest from the master cylinder.
14. Repeat 3 to 7 for the second secondary screw on the front caliper.
15. Refit the front wheel.
16. Repeat 9 to 15 for the front caliper nearest the master cylinder.
17. Remove the C washer and tighten the PDWA switch to 1.4-1.7 Nm (1-1.3 ft lb).