Clean the brake pipe.
Attention: The brake pipes are covered with a plastic layer to protect against corrosion. If this layer is damaged, the tubes can rust. For this reason, do not clean the tubes with a wire brush, sandpaper or a screwdriver.
Check with a lamp-carrier pipelines from the main brake cylinder to the wheel brake cylinders. The master brake cylinder is located in the engine compartment under the expansion tank of the brake system.
The tubes must not be kinked or dented. There should be no places covered with corrosion or with abrasions. Otherwise, replace the tubing section up to the next connection,
Brake hoses connect tubes to wheel brake cylinders on moving parts of the vehicle. They are made of high pressure material but can crack, swell or be damaged by sharp objects over time. In such cases, they must be replaced immediately.
Bend hoses by hand to check for possible damage. The hoses must not be twisted. Observe the color markings on the hoses!
Turn the steering wheel left and right as far as it will go. In this case, the brake hoses must not touch the car parts.
The connection points of the brake hoses and tubes must not be wet with brake fluid.
Attention: If the expansion tank and gaskets are wet, this is not at all a sign of a defect in the brake master cylinder. More likely is the leakage of brake fluid through the vent in the reservoir cap or through the cap gasket.
Brake Fluid Replacement
Special tool:
- Ring wrench 10 mm for air outlet valves.
Consumables:
- Brake fluid specification DOT4.
Brake fluid removes moisture from the air through the pores of the brake hoses and through the vent in the cap of the expansion tank. Therefore, over time, the boiling point of the brake fluid decreases. When the brake system is heavily loaded, therefore, steam bubbles can form in the pipes, which has a strong influence on the operation of the brake system.
Brake fluid should be changed once a year, regardless of mileage, preferably in the spring.
Be careful when handling brake fluid
Suck out the brake fluid from the reservoir to a level of approximately 10 mm.
Attention: Do not empty the expansion tank completely, as air can get into the brake system.
Fill the reservoir with new brake fluid up to the MAX mark.
Put a clean hose on the right rear brake caliper on the bleeder valve, substitute a vessel.
Open the air release valve and "pump" about 10 times the brake pedal.
Close the bleed valve. Top up the expansion tank with new brake fluid.
In the same way, pump out the old brake fluid from the remaining brake calipers.
Caution: The fluid that flows out must be clean and free from bubbles.
Take old brake fluid to a local collection point for special waste.