Brake System Inspection

Bend the brake hose to check for damage

Measure the thickness of front brake pad a together with the metal backing using a vernier caliper. It must be at least 7 mm

Thickness of rear brake pad a together with the metal backing must be at least 7 mm

CAUTION

Dust produced by pad wear and collecting on brake components may contain asbestos, which is hazardous to health. Do not blow this dust away with compressed air and do not inhale it! Do not use gasoline-based solvents to remove dust. Wash dust off with a special brake cleaner or methyl alcohol into a drain container. After wiping brake components with a damp cloth, keep the cloth and the contents of the drain container in a closed, labeled container. Where possible, use asbestos-free components in the future.

In addition to periodic inspections, check the condition of the brake components each time the wheels are removed or when signs of a malfunction appear. For driving safety, the brake system inspection procedures described below are the most important of all vehicle maintenance procedures you will perform.

Signs of Brake System Malfunction

PROCEDURE

1. Disc brake assemblies may have built-in friction pad wear indicators that signal that pad wear has reached a critical level. In this case, replace the pads immediately, otherwise the brake discs will be damaged and will require costly repair.

2. Any of the following signs may indicate a potential brake system defect:

a) The vehicle pulls to one side when the brake pedal is pressed b) Brake assemblies make scraping or squealing noises when braking c) Brake pedal travel is excessive d) Brake pedal pulsates (this is normal only when ABS is operating) e) Brake fluid leaks are present (usually on the inside of the tire or wheel).

3. If at least one of these signs is detected, inspect the brake system immediately. Brake lines and hoses

CAUTION

The brake system mainly uses steel brake lines, except for flexible reinforced hoses at the front wheels and connections at the rear axle. Regular inspection of all these lines is very important.

4. Park the vehicle on level ground and switch off the engine. Remove the wheel covers. Loosen, but do not remove, the wheel bolts on all four wheels.

5. Raise the vehicle with a jack and securely support it on stands.

6. Remove the wheels.

7. Check all brake lines and hoses for cracks and abrasion of the outer coating, leaks, bulges and deformation. Check the brake hoses at the front and rear of the vehicle for signs of softening, cracks, deformation or wear caused by rubbing against other components. Check all fittings for signs of leaks and make sure all brake hose bolts and clamps are securely fastened.

8. Bend the brake hose by hand in both directions to check for damage. Do not twist the hoses. Observe the direction of the colored line marked on the hose!

9. Turn the steering wheel fully to the right and to the left. The hoses must not rub against any part of the vehicle body.

10. If fluid leaks or damage is found, repair it immediately. Brake Pad Thickness Inspection

CAUTION

The thickness of the outer brake pads can be checked through the opening in the wheel disc using a flashlight. The inner pad can be checked with a flashlight and a mirror. If a more accurate assessment of pad thickness is required, remove the wheel and measure the pad with a vernier caliper.

Front Wheel Disc Brake

CAUTION

Experience shows that the brake pad on the front passenger side wears faster than on the driver side. Therefore, it is recommended to remove the front passenger-side wheel to check brake pad thickness.

11. Mark the position of the front wheel relative to the hub with paint. This will allow the balanced wheel to be installed in its original position. Loosen the wheel mounting bolts. The vehicle must be on the ground. Raise the front of the vehicle and support it on stands. Remove the front wheel.

12. Measure the thickness of the pad backing plate (dimension a) on the inner and outer brake pads using a vernier caliper.

13. The wear limit for the front brake pad is 7 mm (including the backing plate). If the pad has reached this limit, replace the brake pad. Refer to Front Brake Pad Replacement.

14. Install the front wheel so that the marks made during removal are aligned. Do not lubricate the wheel mounting bolts. Install the wheel mounting bolts. Lower the vehicle onto the wheels and tighten the bolts in a crisscross pattern to 120 N·m.

CAUTION

Experience shows that 1 mm of brake pad wear corresponds to at least 1,000 km of vehicle mileage. This applies to severe operating conditions. Under normal conditions, pad wear is much lower. At a pad thickness of 10.0 mm, the pad can still be used for at least 3,000 km.

Rear Wheel Disc Brake

15. Check the thickness of the outer brake pad through the opening in the wheel disc, using a flashlight if necessary. It is not necessary to remove the wheel disc. If a wheel cover is fitted, remove it.

16. Check the inner brake pad using a lamp and a mirror.

17. The wear limit for the rear and front brake pads is 7 mm, including the backing plate. Parking Brake

18. The simplest and probably most obvious way to check the parking brake is to park the vehicle on a steep slope with the parking brake applied and the transmission in Neutral (you should be inside the vehicle during this check). If the parking brake does not hold the vehicle from rolling, adjust the parking brake.