Replacing brake fluid (VW Passat B3)

Brake fluid is able to absorb moisture from the air through the pores in the brake hoses and the ventilation hole in the expansion tank cap. Therefore, over time, the boiling point of the brake fluid decreases. Under heavy load on the brakes, vapor locks can form in the brake pipes, which greatly disrupts the operation of the brake system.

Brake fluid should be replaced every 2 years, preferably in the spring.

The workshop uses a device to fill the system and remove air from it to replace the brake fluid. The amount of fluid to replace per one air-bleeding valve is 500 cm³.

Note: This is a sequence of operating procedures for a vehicle without ABS. For procedures applicable to vehicles with ABS, see section "Bleeding the brake system".

Pay attention to the precautions when handling brake fluid, see below.

The original text is available on the portal [www.VWmanual.ru]

Using a suction container, suck out the brake fluid from the expansion tank, leaving a layer of liquid approximately 10 mm thick at the bottom of the tank.

Caution: Do not suck out all the fluid from the reservoir, otherwise air will enter the brake system.

Fill the expansion tank with new brake fluid up to the "MAX" mark.

On the right rear brake caliper, attach a clean transparent hose to the air bleed valve and insert it into a suitable container.

Open the air bleed valve. Press and release the brake pedal approximately 10 times to pump out the old brake fluid from the system.

Close the air bleed valve and fill the expansion tank with new brake fluid.



Use the same method to pump out the old brake fluid from the other calipers.

Caution: The drained brake fluid must in any case be clean and free of air bubbles.

Check the pressure applied and the free travel of the brake pedal. The free travel should be no more than 1/3 of the total pedal travel.

Dispose of old brake fluid at a special collection point for used fuels and lubricants.