Volkswagen Tiguan Service and Repair Manual: Brake System, Bleeding

The bleeding of brake system is described using the Brake Charger/Bleeder Unit -VAS5234-.

WARNING

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

Note

• Brake fluid is poisonous. Due to its caustic nature, it must also never come in 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.
• Rinse any spilled brake fluid with plenty of water.

There must be a positive pressure of 2.0 bar (29 psi) to bleed the hydraulic unit.

Brake System, Bleeding Using Brake Charger/Bleeder Unit - VAS5234-

Special tools and workshop equipment required

• Brake Charger/Bleeder Unit -VAS5234-
• Brake Bleeding Tool Set -VAS6564-

WARNING

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

Pre-Bleeding

Perform the Pre-Bleeding

When a brake fluid reservoir chamber is completely empty on vehicles with EDL, EDL/ASR or EDL/ASR/ESP. This happens if there are leaks in the brake system.

• Connect the Brake Charger/Bleeder Unit -VAS5234-.

Bleeding sequence:

1 - Bleed the left front and right front brake caliper together simultaneously.

2 - Bleed the left rear and right rear brake caliper together simultaneously

• With bleeder bottle hoses attached, leave the bleeder valves open long enough that brake fluid exits without bubbles.

Then hydraulic unit must be bled once more via the "basic setting" function using the Vehicle Diagnostic Tester.

Initiate a basic setting (to bleed the brake system):

Connect the -Vehicle Diagnostic Tester- and select the function.

• Then, the brake system must be bled normally

Bleeding (Normal)

Adhere strictly to the procedure when bleeding the brake system.

• Connect the Brake Charger/Bleeder Unit -VAS5234-.
• Open the bleeder valves in the specified 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 bleed hose. It must fit tightly on the bleeder valve so that no air can get into the brake system.

• With the bleeder bottle hose attached, leave the brake caliper bleeder valve open long enough so that brake fluid exits without bubbles.

Post-Bleeding

Perform the Post-Bleeding Procedure When

• The brake pedal travel is too long, or the so-called "soft brake pedal"

A second technician is required for the post-bleeding procedure.

• Connect the Brake Charger/Bleeder Unit -VAS5234-.
• Depress the brake pedal forcefully and hold
• Open the bleeder valve at the brake caliper.
• Press the brake pedal down until it stops.
• Close the bleeder valve with pedal depressed.
• Release the brake pedal slowly.

This bleeding procedure must be performed five 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, at least one ABS regulation must be performed!