Bleeding will require new brake fluid. Firm «Volkswagen» recommends using brake fluid «FMVSS 116 DOT 4».
Before removing air from the brake system, make sure that all brake drive units and their connections are tight, clean the cover and the surface around the reservoir cover, and thoroughly clean the bleed fittings. Bleeding the brake system is necessary after each repair of the brake system, if the hydraulic brake drive system has been opened.
It is recommended to start pumping from the caliper that has been replaced or repaired. Observe the following sequence of pumped brake mechanisms:
- rear right brake caliper;
- rear left brake caliper;
- front right brake caliper;
- front left brake caliper.
Attention! During pumping, constantly monitor the level of brake fluid in the reservoir and maintain it at the mark «max».
Note. It is not recommended to use the fluid drained from the system to fill the tank, as it is saturated with air, has a lot of moisture and may be contaminated.
Bleed the brakes in the following order:
- remove the dust cap, clean the bleeder fitting and put a rubber hose on it to drain the fluid, and lower its free end into a transparent vessel partially filled with brake fluid;
- ask the assistant to sharply press the brake pedal several times until its sharp opposition appears;
- Loosen the fitting 1/2-1/4 turn with the pedal depressed. Continuing to press the brake pedal, force the liquid in the system together with air through the hose into the vessel. Brake pedal «will leave» to the floor, holding it in this position, wrap the bleeder screw;
Note. Make sure that the end of the hose is constantly immersed in liquid.
- repeat these operations until no more air bubbles come out of the hose;
- add brake fluid to the reservoir, keeping the level near the mark «max»;
- while holding the brake pedal in the depressed position, tighten the fitting to failure and put on the protective cap;
- repeat operations for other wheels;
- check the rubber seal of the reservoir lid;
- after pumping, add brake fluid to the reservoir up to the mark «max»;
- check the tightness of all system connections;
- take a test drive, during which be careful.
Brake Fluid Replacement
Change the brake fluid every two years. At service stations, brake fluid is replaced using a special device for filling and bleeding the brake system. The cylinder of the device is filled with compressed air at a pressure of approximately 400 kPa. For fluid replacement and pumping, the operating pressure of the device is set to 100 kPa.
However, you can change the brake fluid yourself. This will require approximately 2 liters of fresh brake fluid of the specified brand.
In order to prevent air from entering the hydraulic drive system when replacing the brake fluid and spend a minimum amount of time on this operation, adhere to the following rules:
- proceed in the same manner as when bleeding the brakes, but use a hose with a glass tube at the end, which you lower into a vessel with brake fluid;
- while pressing the brake pedal, pump out the old brake fluid until new fluid appears in the tube, then perform two full strokes with the brake pedal and, holding it down, tighten the fitting;
- constantly monitor the level of brake fluid in the reservoir and top up the fluid in a timely manner to the level «max»;
- repeat this operation on each brake cylinder in the same order as when pumping;
- after changing the brake fluid, fill the reservoir to the maximum level and check the operation of the brakes while driving, being careful.
Visitor comments