Hydraulic System, Bleeding With Brake Charger/Bleeding Unit
Special tools and workshop equipment required
- Brake Charger/Bleeder Unit: VAS5234 with Brake Bleeder Adapter : VAS5234/1A
- Or
- Brake Filling and Bleeding Equipment: VAS6860
- Read the operation manual for Brake Charger/Bleeder Unit: VAS5234 or Brake Filling and Bleeding Equipment: VAS6860 .
- Wrench - Brake Bleeder Set: VAS5519
- Brake Bleeding Tool Set: VAS6564
The brake system is divided by the axle on this vehicle.
Right and left front axle
Right and left rear axle
The bleeding of the hydraulic system using the : VAS5234 is described.
An initial pressure of 2 bar (29 psi) is required to bleed the ABS Hydraulic Unit -N55-.
If the hydraulic system cannot be bled correctly, continue with BLEEDING WITH ABS Hydraulic Unit -N55- PUMP .
Procedure
- Wheels are removed. Refer to WHEELS AND TIRES .
Make sure that the brake fluid reservoir is always filled, but not over the "MAX" mark.
-- Fill the brake fluid reservoir up to the "MAX" mark.
-- Connect the : VAS6860 .
-- Attach the : VAS5234/1A on the brake fluid reservoir.
-- Adjust the pressure direction on the : VAS5234 . Refer to the : VAS5234 Owner's Manual.
Or
-- Adjust the pressure direction on the : VAS6860 . Refer to the : VAS6860 Owner's Manual.
-- Remove the protective cap -3- from the bleed screw -1- on the respective brake caliper.
-- Connect the bleeder bottle hose -2- as shown.
Use a suitable bleeder hose. 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.
Bleed the brake caliper at each bleed screw.
Bleeding Sequence
- Outer Left Front Brake Caliper
- Inner Left Front Brake Caliper
- Outer Right Front Brake Caliper
- Inner Right Front Brake Caliper
- Left Rear Brake Caliper
- Right Rear Brake Caliper
Bleed the brake caliper at each bleed screw. If the brake caliper has two bleed screws, bleed the outer screw first.
-- Leave the bleed screw open with the brake fluid hose connected, until brake fluid flows out clear and without air bubbles.
-- Press brake pedal five times to assist the bleeding procedure.
-- Tighten the bleed screw, remove the bleeder hose and place the dust cap on the bleed screw.
-- Repeat the bleeding procedure in the specified sequence for the remaining brake calipers.
-- Fill the brake fluid reservoir up to the "MAX" mark and tighten the cap.
Do not add brake fluid above the "MAX" mark otherwise it will leak out of the reservoir.
-- Start the engine and check the brake pedal travel and pressure.
-- If the pedal travel is too long, check the brake system for leaks or repeat the bleeding procedure.
If the hydraulic system cannot be bled correctly, continue with, refer to BLEEDING WITH ABS Hydraulic Unit -N55- PUMP .
A road test must be performed after bleeding. During this, at least one ABS regulation must be performed at all four wheels!
Risk of accident!
- Make sure the brakes are working correctly before driving the vehicle for the first time.
Changing the Brake Fluid
Refer to 413.
Tightening Specifications
- Refer to OVERVIEW - FRONT BRAKES
- Refer to OVERVIEW - REAR BRAKES