Warning: Dust from worn pads and accumulating on brake components may contain hazardous asbestos. Do not blow this dust out with compressed air or inhale it! Do not use gasoline-based solvents to remove dust. Dust should be washed off with a special brake system cleaner or methyl alcohol in a drain container. After wiping the brake system components with a damp cloth, keep the cloth and the contents of the drain container in a closed and labeled container. In the future, if possible, try to use asbestos-free components.
Warning: In addition to checks at regular intervals, the condition of the brake mechanisms should be carried out each time the wheels are removed or if there are signs of a malfunction in the system. To ensure driving safety, the brake check procedures described below are the most important of all vehicle maintenance procedures you perform.
Signs of problems in the brake system
Disc brakes may have built-in lining wear indicators that indicate when lining wear has reached a critical level. In this case, the pads should be changed immediately, otherwise the brake discs will be damaged and they will require costly repairs.
Any of the following symptoms may indicate a potential defect in the brake system:
1. When depressing the brake pedal, the car «leads away» one way.
2. Brake mechanisms make scraping or squealing sounds when braking.
3. The brake pedal has excessive travel.
4. Brake pedal pulsing (this is normal only when the ABS system is working).
5. Brake fluid leaks (usually on the inside of a tire or wheel).
If at least one of these signs is found, immediately inspect the elements of the brake system.
Brake lines and hoses
Warning: The brake system mainly uses steel brake pipes, with the exception of flexible reinforced hoses at the front wheels and as connections at the rear axle. Regular inspection of all these lines is very important.
1. Jack up the vehicle and place it securely on jack stands.
2. Remove the wheels (refer to Section Check the condition of the tires and the pressure in them. Designation of tires and disks of wheels. Wheel rotation and replacement and chapter materials Controls and techniques for safe operation).
3. Check all brake lines and hoses for cracks and chafing in their outer coating, leaks, swelling and deformation. Check the brake hoses at the front and rear of the vehicle for signs of softening, cracking, deformation, or wear due to rubbing against other components. Check all fittings for signs of leaks and make sure all bolts and brake hose clamps are secure.
4. Bend the brake hose back and forth with your hands to check for damage. Hoses should not be twisted. Pay attention to the direction of the colored line marked on the hose!
5. Turn a steering wheel to the right and to the left against the stop. The hoses must not touch the structural elements of the vehicle. If fluid leaks or damage is found, they must be repaired immediately. For a more detailed description of the procedure for repairing the brake system, refer to Chapter Brake system.
Checking the thickness of the brake pads
Checking the thickness of the brake pads of the front wheels
Checking the thickness of the rear brake pads
The thickness of the outer brake pads can be checked through the opening in the wheel rim using a flashlight. The inner shoe can be checked with a flashlight and a mirror. If you need to more accurately estimate the thickness of the pad, you should remove the wheel and measure the pad with a caliper.
Warning: Experience has shown that brake pad wear on the front passenger side is greater than on the driver's side. Therefore, to check the thickness of the brake pad, it is recommended to remove the wheel from the front passenger side.
1. Mark with paint the position of the front wheel in relation to the hub. This will allow you to set the balanced wheel in its working position. Loosen the wheel bolts. In this case, the car must be on the ground.
2. Raise the front of the vehicle and place on stands. Remove the front wheel.
3. Thickness (arrows in the illustration) check the inner and outer pads through the opening in the caliper.
4. The wear limit of the thickness of the brake pads is reached if the pad lining has a thickness of 2.0 mm (7 mm with base plate). In this case, the brake shoe must be replaced, refer to Sections Removal and installation of front brake pads And Removal and installation of pads of brake mechanisms of back wheels.
Warning: In practice, 1 mm of brake pad wear corresponds to at least 1000 km of the car's run. This rule corresponds to adverse operating conditions of the car. Under normal conditions, pad wear is significantly less. With pad thickness 10.0 mm (with base plate) the block can still be operated for at least 3000 km.
5. Check up a possibility of leak of a brake liquid in support. If there is a leak, repair the caliper immediately (service station work).
6. Visually inspect the brake discs for grooves, corrosion, and cracks. Ventilated discs with hairline cracks up to 25 mm long, which may be caused by increased stress, do not need to be replaced. In case of cracks and grooves with a depth of more than 0.5 mm, the brake discs must be replaced.
7. Check the thickness of the brake discs, refer to Chapter Section Brake system.
8. Reinstall the front wheels so that the marks made during removal match. Pre-lubricate with a thin layer of bearing grease the centering belt of the wheel disk on the hub. Do not grease wheel bolts. Replace rusty bolts. Wrap bolts. Lower the car onto the wheels and tighten the bolts crosswise.
Checking and running in the parking brake
1. Drive the car and stop it on the road with light traffic.
2. Pull out the parking brake lever 3 prongs and release the foot brake.
3. The parking brake is effective enough if the vehicle is held securely.
Caution: If the parking brake pushes up to 5 teeth further, the brake needs to be adjusted.
Running in brake
The parking brake is provided by 2 drum brakes located in the rear disc brakes. Due to this, the parking brake wears out slightly. Corrosion on the brake drum or dirt on the brake pads can reduce the braking torque. The brake must be run in to achieve optimum performance.
1. Drive on a dry, light road.
2. At a speed of about 50 km/h, put the gearbox in neutral. Pull out the parking brake handle. So stop the car. When braking with the parking brake, the brake light does not come on. For this reason, be especially alert to traffic moving behind you.
3. Continue driving the vehicle at a constant speed of approximately 50 km/h.
4. Pull out the parking brake handle for about 10 seconds and release.
Warning: If the parking brake does not apply well, repeat the braking process after it has cooled down.
5. If the parking brake does not release well after checking or after running in and adjusting it is tightened on one side, check the brake shoes and cables, replace if necessary.
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