Volkswagen Cars 2000-05

Bleeding the Brake System


If your vehicle is equipped with ABS, and you have allowed the master cylinder to run dry, a scan tool will be needed to successfully bleed all of the air out of the ABS valve body. It is recommended that this bleeding procedure be done by a authorized repair facility.

When any part of the hydraulic system has been disconnected for repair or replacement, air may get into the lines and cause spongy pedal action (because air can be compressed and brake fluid cannot). To correct this condition, it is necessary to bleed the hydraulic system so to be sure all air is purged.

When bleeding the brake system, bleed one brake cylinder at a time, beginning at the cylinder with the longest hydraulic line (farthest from the master cylinder) first. ALWAYS Keep the master cylinder reservoir filled with brake fluid during the bleeding operation. Never use brake fluid that has been drained from the hydraulic system, no matter how clean it is.

Use only new DOT 3 or 4 brake fluid in all Volkswagen vehicles. Do not use silicone (DOT 5) fluid. Even the smallest traces can cause severe corrosion to the hydraulic system. All brake fluids are corrosive to paint.

The primary and secondary hydraulic brake systems are separate and are bled independently. During the bleeding operation, do not allow the reservoir to run dry. Keep the master cylinder reservoir filled with brake fluid.

  1. Clean all dirt from around the master cylinder fill cap, remove the cap and fill the master cylinder with brake fluid until the level is within 1 / 4 in. (6mm) of the top edge of the reservoir.
  3. Clean the bleeder screws at all 4 wheels. The bleeder screws are located on the back of the brake backing plate (drum brakes) and on the top of the brake calipers (disc brakes).
  5. Attach a length of rubber hose over the bleeder screw and place the other end of the hose in a glass jar, submerged in brake fluid.
  7. Open the bleeder screw 1 / 2 - 3 / 4 turn. Have an assistant slowly `depress the brake pedal.
  9. Close the bleeder screw and tell your assistant to allow the brake pedal to return slowly. Continue this process to purge all air from the system.
  11. When bubbles cease to appear at the end of the bleeder hose, close the bleeder screw and remove the hose. Tighten the bleeder screw to the proper torque:
  13. Check the master cylinder fluid level and add fluid accordingly. Do this after bleeding each wheel.
  15. Repeat the bleeding operation at the remaining 3 wheels, ending with the one closet to the master cylinder.
  17. Fill the master cylinder reservoir to the proper level.

The following procedure is for models not equipped with Anti-lock Braking Systems (ABS).

The brake fluid should be replaced at least every 2 years as it is hygroscopic and absorbs moisture from the ambient air. Always keep brake fluid in a sealed container. Only use a brake fluid that meets the US standard FMVSS 116 DOT 4.

Brake fluid is poisonous and corrosive. Avoid spilling brake fluid on the vehicle's paint. It will damage the finish. If a spill does occur, wash it immediately with water.

The purpose of bleeding the brakes is to expel air trapped in the hydraulic system. The system should be checked for fluid condition, brake hose condition and air whenever the pedal feels spongy. The system must be bled whenever it has been opened, repaired, or a hydraulic component replaced. If you are not using a pressure bleeder, you will need an assistant for this job.

NEVER reuse brake fluid that has been bled from the brake system. Brake fluid absorbs moisture that can lower its boiling point, therefore re-using old, used, or contaminated fluid can decrease the effectiveness of the braking system.