Brake Bleeding: Service and Repair

Brake System, Bleeding

Description covers bleeding of the brake system using the brake charger/bleeder unit (VAS 5234).


Only use new brake fluid conforming to VW standard (VW 501 14).

• Brake fluid is poisonous. Due to its caustic nature, it must also never be brought into contact with paint.

• Brake fluid is hygroscopic, meaning that it absorbs moisture from the surrounding air, and must therefore be stored in air tight containers.

• Wash off any spilled brake fluid with plenty of water.

There must be a positive pressure of 2 bar to bleed the hydraulic unit.

Using the Brake Charger/Bleeder Unit (VAS 5234)

Special tools, testers and auxiliary items required

• Brake Charger/Bleeder Unit (VAS 5234)

• Tool Set for Brake Bleeding (VAS 6564)


Only use new brake fluid conforming to VW standard (VW 501 14).

Bleeding

Adhere strictly to this procedure when bleeding the brake system.

- Connect the brake charger/bleeder unit (VAS 5234).

- Open the bleed valves in the following sequence and bleed the brake calipers:

1- Left front brake caliper

2 - Right front brake caliper

3 - Left rear brake caliper

4 - Right rear brake caliper

Use a suitable hose for bleeding. It must fit tightly on the bleed valve so that no air gets into the brake system.

- With the bleeder bottle hose attached, leave the bleed valve open long enough that brake fluid exits without bubbles.

Post-Bleeding

Perform a post-bleeding when:

• The brake pedal travel is too long, or you have a so-called "soft brake pedal"

• One chamber in the brake fluid reservoir is completely empty on a vehicle with Electronic Differential Lock (EDL), EDL/Anti-Slip Regulation (ASR) or EDL/ASR/Electronic Stabilization Program (ESP) This will happen if there are leaks in the brake system.

A second technician is required during the post-bleeding:

- Press the brake pedal forcefully and hold.

- Open the bleed valve on the brake caliper.

- Press the brake pedal down to the stop.

- Close the bleed valve when the brake pedal is pushed down all the way.

- Release the brake pedal slowly.

This bleeding procedure must be performed 5 times per brake caliper.

Bleeding sequence:

1- Left front brake caliper

2 - Right front brake caliper

3 - Left rear brake caliper

4 - Right rear brake caliper

A road test must be performed after bleeding. During this test, at least one Anti-lock Brake System (ABS) stop must be performed!