Before concluding that the brake system has failed, check the condition and inflation pressure of the tires and the uniform loading of the vehicle (see chapter Car maintenance). Also, check that the wheel alignment is correct (see chapter Steering).
Symptom | Possible reason |
When braking, the directional stability of the car is violated | Tires incorrectly inflated (see chapter Car maintenance). |
Wheel alignment out of alignment (see chapter Steering). | |
Tires of different sizes are installed on one axle. | |
Broken brake lines or hoses (see chapter Brake system). | |
Damaged brake caliper (see chapter Brake system). | |
Loose suspension components (see chapter Front suspension). | |
Loose brake caliper (see chapter Brake system). | |
Extraneous noises occur during braking (grinding or high-frequency squealing) | The friction linings of the brake pads of the front or rear brake mechanisms are worn down to the substrate metal. The screech is emitted by pad wear indicators when rubbing against the brake discs. Replace pads immediately (see chapter Brake system). |
There is brake vibration. (pedal pulsation) On models equipped with ABS, brake pedal pulsations are a normal function of the system. | Excessive brake disc lateral runout (see chapter Brake system). |
The parallelism of the walls of the brake disc is violated above the permissible limit (see chapter Brake system). | |
There is uneven wear of the brake pads due to jamming of the caliper as a result of incorrect clearance setting or dirt ingress (see chapter Brake system). | |
Faulty brake disc (see chapter Brake system). | |
Excessive brake pedal travel | There is a partial malfunction of the brake system (see chapter Brake system). |
The level of brake fluid in the GTZ has dropped (see chapters Car maintenance and Brake system). | |
Air has entered the hydraulic system (see chapters Car maintenance and Brake system). | |
Applying too much force to the brake pedal is required to stop the vehicle | Faulty brake booster unit (see chapter Brake system). |
There is a partial malfunction of the brake system (see chapter Brake system). | |
Excessively worn brake pads/boots (see chapter Brake system). | |
Piston stuck (And) caliper (see chapter Brake system). | |
Greased friction linings of brake pads (see chapter Brake system). | |
New brake pads are installed and have not yet run in - it takes time for the pads to run in to the discs. | |
brakes "seized" | GTZ pistons do not return properly (see chapter Brake system). |
Broken brake lines/hoses (see chapters Car maintenance and Brake system). | |
Parking brake adjustment out of order (see chapter Brake system). | |
The functioning of the automatic adjustment mechanism of the rear drum brakes is disrupted (with appropriate equipment) (see chapter Brake system). | |
Disturbed uniform distribution of braking force | Faulty vacuum brake booster (see chapter Brake system). |
Stuck foot brake pedal mechanism (see chapter Brake system). | |
There is a softness of the brake pedal when it is squeezed out | Air has entered the hydraulic system (see chapter Brake system). |
Loose GTS mounting bolts (see chapter Brake system). | |
Faulty GTZ (see chapter Brake system). | |
Brake pedal sinks to the floor with little to no resistance | The liquid level in the GTZ reservoir has dropped excessively due to leaks through the piston (And) calipers, loose or damaged hydraulic brake lines (see chapter Brake system). |
The parking brake does not securely fix the vehicle | Parking brake adjustment out of order (see chapter Brake system). |
Worn or dirty friction linings of the parking brake shoes (see chapter Brake system). |