Checking brake system for leaks

For the check, the underbody must be dry so that you can see leaking points. Brake fluid can also be hidden under dirt. Areas that are dark with moisture suggest a leak.

PROCEDURE

Check all connection points, as well as the disc brake calipers and the drum brake backing plates, behind which the wheel brake cylinders are located.

Brake hoses must not be damp, swollen or chafed. Otherwise, they must be replaced.

Brake lines have an anti-corrosion coating. If this protective layer is damaged, rust may begin to form. Therefore, never clean serviceable brake lines with a screwdriver, emery cloth or wire brush.

If the protective layer is damaged, apply a thin coat of anti-corrosion primer.

Lines with signs of rust or that are crushed must be replaced.

Are all bleeder valves protected by dust caps? They are located on the disc brake calipers or inside the drum brake backing plates.

You can perform a simple brake system pressure check yourself:
Press the brake pedal down with full force.

It must not give way even after several minutes under full load; otherwise, one of the seals in the brake master cylinder is defective.

Due to a leaking seal, the fluid level in the reservoir does not drop, but the compressed fluid flows past the piston in the master cylinder to the other side, where there is no pressure.

Leaking points on the piston seals of disc brake calipers and drum brake wheel cylinders can be identified by dark areas on the calipers or drum brake backing plates.

If you are not sure, consult a workshop.