Correctness of provision of a pedal of a brake and when pressing it against the stop (the working course of a pedal) serves one of criteria for check of serviceability of the brake system in a free state. At the same time the provision of a pedal in many respects ensures correct functioning of system. If the pedal is from a floor at distance which is more standard, perhaps incomplete disinhibition of wheels at a pedal otpuskaniye (at the same time usually there is no free wheeling of a pedal). If the pedal is too low, the decrease in efficiency of brakes caused by reduction of the working course of a pedal is possible. Adjustment of provision of a pedal is not provided, it is provided structurally at serviceability of all details of the drive of brakes. In case of a rejection of the provision it nominal check a condition of all details and knots of the drive and replace faulty.

You will need a ruler.

1. Press a brake pedal against the stop and measure distance from an overlay of the platform of a pedal to a floor.

Note The ruler has to be established perpendicular to the floor plane.

2. Release a pedal and repeatedly measure distance from an overlay of the platform of a pedal to a floor in a free state. This distance has to be 140 mm. The difference of the sizes received as a result of two measurements is also the full working course of a pedal which has to be 55 mm.

3. Check a free wheeling of a pedal of a brake for what move a pedal with a hand until the termination of movement of a pedal without resistance. Determine value of a free wheeling by a ruler, it has to be 3–8 mm. Discrepancy of a free wheeling to the specified value can be caused by the following reasons:

– the raised side play in connection of a fork of a pusher of the vacuum amplifier and a pedal. It can be a consequence of wear of a finger of a fork;

– jamming of pistons in the main brake cylinder;

– jamming of a plunger in the amplifier of brakes.

4. If the working course of a pedal is more than value given in item 2, then it indicates availability of air in a hydraulic actuator of brakes or extreme wear of overlays of brake shoes, brake disks or drums. Remove air from a hydraulic actuator (see. "Pumping of a hydraulic actuator of the brake system") or replace brake shoes (see. "Replacement of brake shoes of the brake mechanism of a forward wheel"; "Replacement of brake shoes of the brake mechanism of a back wheel"), disks (see. "Replacement of a brake disk") or drums (see. "Removal and installation of the brake drum").

Prevention If the pedal pressed against the stop and withheld in this situation gradually moves to a floor, it indicates leak of liquid from a hydraulic actuator or malfunction of the main brake cylinder. These malfunctions are very dangerous therefore immediately find the place of leak and eliminate it or replace the main brake cylinder!