If the brake light switch is too close to the pedal, it does not return to its original position, valve 9 (see fig. 193), pressing against the body 22, separates cavities A and E and incomplete release of the wheels occurs when the pedal is released.
The position of the brake light switch is adjusted by moving it with nut 4 loosened (see fig. 199). Install it so that the brake light buffer 5 slightly touches the pedal stop 6, while the free travel of the pedal should be 3-5 mm. After completing the adjustment, tighten the nut 4. It is necessary to remember that the adjustment of the free travel of the brake pedal should be carried out with the engine not running.
If moving the brake light switch does not eliminate the incomplete release of the brake mechanisms, then disconnect the brake master cylinder from the vacuum booster and check the protrusion of the adjusting bolt 28 (see fig. 193) relative to the plane of the main cylinder flange mounting (size 1.25-0,2 mm), as indicated earlier (see section "Vacuum booster"). Set this size by holding the end of rod 3 with a special key and tightening or loosening bolt 28 with another key, as indicated in section "Measuring the protrusion of the vacuum booster rod".