Hydraulic System, Bleeding
Special tools and workshop equipment required
- Bleeding Equipment:VAS6860 or Brake Charger/Bleeder Unit: VAS5234
- Brake Charger/Bleeder Unit - Adapter:VAS5234/1A
- Collection bottle from the Bleeding Equipment:VAS6860 or Brake Charger/Bleeder Unit: VAS5234
- Wrench - Brake Bleeder Set:VAS5519
- Brake Bleeding Tool Set:VAS6564
Bleed Brakes
The brake system is divided by axle:
- Left and right front wheel
- Left and right rear wheel
| Component | Conventional Bleeding | Bleeding with the Vehicle Diagnostic Tester |
|---|---|---|
| Brake line from brake booster to hydraulic unit | 1 | 2 |
| Hydraulic Unit | 1 | 2 |
| Suction Line | 1 | 2 |
| Brake line from hydraulic unit to brake caliper | 1 | - |
| Brake Caliper | 1 | - |
- Depending on the wheel combination, remove the wheels. Refer to WHEELS AND TIRES .
1. Conventional Bleeding
-- Open the access cover.
-- Attach the Brake Bleeder Adapter:VAS5234/1A to the brake fluid reservoir (example illustration).
-- Connect the of the Bleeding Equipment: VAS6860 or Brake Charger/Bleeder Unit: VAS5234 .
-- Set a work pressure of 2.0 bar (29.01 psi) at the Bleeding Equipment:VAS6860 or Brake Charger/Bleeder Unit: VAS5234 and turn it on. Refer to the appropriate Service Information.
-- Remove the protective cap -3- from the bleed screw -1- on the respective brake caliper (example illustration).
- Use a suitable bleeder hose -2-. It must be seated tightly on the bleed screw so that no air can enter the brake system.
The front brake calipers each have two bleed screws.
-- Position the socket -3- at the bleed screw using the ratchet -2-.
-- Attach the bleeder hose -1- through the socket onto the bleed screw.
-- Position the socket -3- at the inner bleed screws using the ratchet -2-.
-- Attach the bleeder hose -1- through the socket onto the bleed screw.
- Bleed the brake caliper at each bleed screw.
Bleeding sequence
- Outer left front brake caliper
- Left front inner brake caliper
- Outer right front brake caliper
- Right front inner brake caliper
- Left Rear Brake Caliper
- Right Rear Brake Caliper
-- Open the bleed screw and leave open until the leaking brake fluid is clear and without bubbles.
-- Press brake pedal five times to assist the bleeding procedure.
-- Tighten the bleed screw, remove the bleeder hose and place the protective cap on the bleed screw.
-- Repeat the bleeding procedure in the specified sequence for the remaining brake calipers.
-- Fill the brake fluid reservoir under consideration of brake pad wear up to the "MAX" mark and tighten the fuel cap (example illustration).
- Do not add brake fluid above the "MAX" mark otherwise it will leak out of the reservoir.
-- Carefully remove leaked brake fluid.
-- Start the engine and check the brake pedal travel and pressure.
- If the brake pedal travel and brake pedal pressure are not OK, perform the bleeding procedure using the Vehicle Diagnostic Tester.
2. Bleeding using the Vehicle Diagnostic Tester
-- Connect the battery charger. Refer to BATTERY, CHARGING .
-- Attach the Brake Bleeder Adapter:VAS5234/1A to the brake fluid reservoir (example illustration).
-- Connect the of the Bleeding Equipment: VAS6860 or Brake Charger/Bleeder Unit: VAS5234 .
-- Set a work pressure of 2.0 bar (29.01 psi) at the Bleeding Equipment:VAS6860 or Brake Charger/Bleeder Unit: VAS5234 and turn it on. Refer to the appropriate Service Information.
-- Select the "Basic setting / Brake system, bleeding" Program. Refer to DIAGNOSTIC ENTRY .
-- Follow the instructions in the Vehicle Diagnostic Tester display.
-- Check the brake pedal travel and brake pedal pressure after bleeding.
- If the brake pedal travel and brake pedal pressure are not OK, repeat the bleeding procedure using the Vehicle Diagnostic Tester.
-- Remove the Adapter:VAS5234/1A from the brake fluid reservoir.
-- Fill the brake fluid reservoir under consideration of brake pad wear up to the "MAX" mark and tighten the fuel cap (example illustration).
-- Carefully remove leaked brake fluid.
Tightening Specifications
- Refer to OVERVIEW - FRONT BRAKES
- Refer to OVERVIEW - REAR BRAKES
- Refer to WHEELS AND TIRES .