Before concluding that the brake system has failed, check the condition and inflation pressure of the tires and the uniformity of the vehicle loading (see chapter Routine car maintenance). In addition, check that the wheel alignment angles are correct (see chapter Steering).
| Symptom | Possible cause |
| When braking, the vehicle's directional stability is impaired | The tires are not inflated correctly (see chapter Routine car maintenance). |
| Wheel alignment is out of adjustment (see chapter Steering). | |
| Tires of different sizes are installed on one axle. | |
| The brake lines or hoses are clogged (see chapter Brake system). | |
| The brake caliper is damaged (see chapter Brake system). | |
| The suspension components have become loose (see chapter Front suspension). | |
| The brake caliper mount has become loose (see chapter Brake system). | |
| Extraneous noises occur during braking (grinding or high-pitched squealing noise) | The friction linings of the brake pads of the front or rear brake mechanisms are worn down to the metal substrate. The squealing noise is produced by the pad wear indicators when they rub against the brake discs. Replace the pads without delay (see chapter Brake system). |
Brake vibration occurs. (pedal pulsation) On models equipped with ABS, brake pedal pulsations are a consequence of the normal operation of the system. | There is excessive lateral runout of the brake disc (see chapter Brake system). |
| The parallelism of the brake disc walls is violated above the permissible limit (see chapter Brake system). | |
| There is uneven wear of the brake pads due to the caliper seizing as a result of incorrect clearance setting or dirt ingress (see chapter Brake system). | |
| The brake disc is faulty (see chapter Brake system). | |
| Brake pedal travel is too long | There is a partial malfunction of the braking system (see chapter Brake system). |
| The brake fluid level in the master cylinder has dropped (see Chapters Routine car maintenance and Brake system). | |
| Air has entered the hydraulic system (see Chapters Routine car maintenance and Brake system). | |
| To stop the car, it requires applying excessive force to the brake pedal | The brake booster unit is faulty (see chapter Brake system). |
| There is a partial malfunction of the braking system (see chapter Brake system). | |
| Brake pads/shoes excessively worn (see chapter Brake system). | |
| The caliper piston is stuck (see chapter Brake system). | |
| The friction linings of the brake shoes are oily (see chapter Brake system). | |
| New brake pads have been installed and have not yet been run in - it takes time for the pads to become accustomed to the discs. | |
| The brakes are "seized" | The proper return of the master cylinder pistons does not occur (see chapter Brake system). |
| The brake lines/hoses are not clear (see Chapters Routine car maintenance and Brake system). | |
| The parking brake adjustment is incorrect (see chapter Brake system). | |
| The automatic adjustment mechanism of the rear drum brakes is malfunctioning (with appropriate equipment) (See Chapter Brake system). | |
| The uniformity of distribution of braking force is disturbed | The brake booster is faulty (see chapter Brake system). |
| The foot brake pedal mechanism is jammed (see chapter Brake system). | |
| There is a softness in the brake pedal when it is pressed | Air has entered the hydraulic system (see chapter Brake system). |
| The brake master cylinder mounting bolts have become loose (see chapter Brake system). | |
| The GTZ is faulty (see chapter Brake system). | |
| The brake pedal sinks to the floor with virtually no resistance | The fluid level in the brake master cylinder reservoir has dropped excessively due to leaks through the caliper piston, loose fastening or damage to the hydraulic brake lines (see chapter Brake system). |
| The parking brake does not provide reliable fixation of the car | The parking brake adjustment is incorrect (see chapter Brake system). |
| The friction linings of the parking brake shoes are worn or dirty (see chapter Brake system). |