1. The reason for the decrease in braking efficiency may be unsatisfactory operation vacuum booster. For its express check, press the brake pedal several times with the engine off to remove the vacuum in the amplifier, and then, while holding the pedal, start the engine. If after starting the engine the pedal drops a little, the vacuum booster is working.
2. If the pedal has remained motionless, check up an integrity and reliability of fastening of the hose connecting the vacuum amplifier with the inlet pipeline of the engine. Replace or repair defective hose. If the hose is OK, it is required vacuum booster replacement.
If braking is accompanied by beating and pulsing of the brake pedal, you should first check the condition of the front disc brakes.
3. Having installed the car on a jack, remove the front wheel and inspect the brake disc.
The thickness of the brake disc must be at least 10.8 mm. The surface of the disc must be even and smooth on both sides. If the surface of the disc is covered with rust in places, which usually happens after a long parking of the car with wet brakes, try cleaning the working surface with a fine emery cloth. If this procedure does not help, you will have to give the discs for grinding or replace with new ones.
4. Check the mobility of the brake pads. To do this, use a screwdriver to try to take the pads away from the brake disc. If the pads cannot be separated, then «jammed» piston in the brake cylinder.
Warning! Jamming of the piston of the brake cylinder leads to the constant braking of the corresponding wheel when the pedal is released and the car skids when braking.
Note. The parking brake actuates the rear brakes by a cable connecting the parking brake lever and the brake shoe control mechanism. Many drivers try to use the parking brake as little as possible in order to prolong its life, and... achieve the opposite result. If you do not use the parking brake, dirt and moisture stagnate in the sheaths of the cable, the cable becomes rusty, stops moving and breaks. Therefore, use the parking brake when necessary, but do not forget from time to time adjust the parking brake.
5. To adjust the parking brake, lift the lever up four or five ratchet clicks. From under the vehicle, loosen the tensioner locknut and use the adjusting nut to tension the cable.
Helpful advice. After adjustment, check that the rear wheels turn freely. If they turn tight, then slightly loosen the adjusting nut and fix it with a lock nut.