To complete the work, you will need a ruler or tape measure.
Execution sequence
1. We prepare the car for work («Preparing the car for maintenance and repair»).
2. Install a ruler or tape measure near the pedal and measure the distance from the floor to the outer surface of the brake pedal.
3. Pressing the pedal with your hand, we lower it until we feel an increase in resistance to the movement of the pedal.
We repeat measurements. By the difference between the obtained values, we determine the free play.
Warning! The presence of a free play of the brake pedal ensures that after the braking is stopped, the pistons of the main brake cylinder will return to their original position, and as a result, there will be no excess pressure in the brake hydraulic drive. When the brake light switch is set so that it limits the rearward travel of the brake pedal, pressure can be maintained in the brake system at which the brake pads will brake continuously.
Recommendation. If the free play of the brake pedal is less than the optimum value, it is necessary to adjust the position of the brake light switch («Brake light switch - check and replace»). Increased brake pedal free play can be caused by play in the drive mechanism. Worn parts need to be replaced. Also, the cause of the malfunction may be the presence of air in the hydraulic brake actuator or a malfunction of the master brake cylinder. Fault detected must be corrected («Service brake drive»).