Hydraulic System, Bleeding With Brake Charger/Bleeding Unit

Special tools and workshop equipment required

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-.

Procedure

Fig 1: Brake Fluid Reservoir

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TIP:

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 Brake Filling and Bleeding Equipment:VAS6860 .

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-- Attach the :VAS5234/1A to the brake fluid reservoir.

-- Adjust the pressure direction on the :VAS5234 . Refer to the Parts Information.

-- Remove the protective cap -3- from the bleed screw -1- on the respective brake caliper.

Fig 2: Identifying Protective Cap, Bleed Screw And Container Bleeder Hose

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-- Connect the bleeder bottle hose -2-.

TIP:

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

-- 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 under consideration of brake pad wear up to the "MAX" mark and screw on the fuel cap.

Fig 3: Brake Fluid Reservoir

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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.

A road test must be performed after bleeding. While doing so, at least one ABS control must be performed at all four wheels.

CAUTION:

Faulty brakes increase the risk of an accident.

- Make sure the brakes are working correctly before driving the vehicle for the first time.

Changing the Brake Fluid

Tightening Specifications