Location of the bleed valve on the front caliper
The bleed valve is indicated by an arrow.
Location of the bleeder valve on the rear working brake cylinder
The bleed valve is indicated by an arrow.
Bleeding the hydraulic brake drive is necessary to remove air, which significantly reduces braking efficiency. Air can get into the hydraulic drive due to depressurization of the system during repairs, replacement of individual components or brake fluid. The presence of air in the drive is indicated by an increased stroke of the brake pedal and its "softness".
If there is no air in the brake system, the pedal should travel about half of its travel. To eliminate the influence of the vacuum booster on pumping the brakes, remove air with the engine off.
1. Before bleeding, check the tightness of all brake drive units and their connections.
2. Remove the dust cap from the wheel cylinder bleeder, clean it and put a clean transparent hose on it, lower the other end into a container partially filled with brake fluid. The container must be at least 300 mm above the bleeder port. This prevents air from entering the cylinder through the bleed screw threads.
3. Press the brake pedal sharply 3–5 times with an interval of 2–3 seconds, unscrew the bleed valve half a turn while pressing the pedal.
4. Continuing to press the pedal, expel the liquid in the system together with air through the hose into the container.
5. After the pedal reaches the extreme forward position, and the flow of fluid through the hose stops, screw the bleeder in until it stops.
6. Repeat these operations until the air flow from the hose stops.
7. While holding the pedal down, screw in the bleed screw until it stops and remove the hose.
8. Wipe the bleeder valve and install the protective cap.
9. Repeat these operations for other wheels.
Attention! When removing air, constantly monitor the presence of brake fluid in the tank, preventing its bottom from being exposed, because. this will allow air to enter the system.
Pumping sequence
Conventional braking system
- 1) Right rear wheel.
- 2) Left front wheel.
- 3) Left rear wheel.
- 4) Right front wheel.
Bendix system with ABS
Disconnecting the three-pin connector when bleeding the Bendix system with ABS
Before performing bleeding, turn off the ignition and disconnect the brown three-pin connector from the hydraulic assembly of the modulator.
Location on the hydraulic modulator of the main and additional bleeder of the Bendix system with ABS
1 - main bleeder valve,
2 - additional bleed valve
- 1) The rear brake furthest from the master cylinder.
- 2) The rear brake closest to the master cylinder.
- 3) The front brake furthest from the master cylinder.
- 4) Front brake closest to the master cylinder.
- 5) Hydraulic modulator.
Bosch system with ABS
- 1) Left front wheel.
- 2) Right front wheel.
- 3) Left rear wheel.
- 4) Right rear wheel.
If it is difficult to bleed a Bosch hydraulic system with ABS, bleed in the following order:
- 1) Right rear brake.
- 2) Left rear brake.
- 3) Left front brake.
- 4) Right front brake.