9.4. Check and adjustment of provision of a pedal of a brake

Correctness of provision of a pedal of a brake and when pressing 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.

It will be required to you: a ruler, keys "on 13", "on 14", passatizh.

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 in a free state to a floor. This distance has to be 100–105 mm. The difference of the sizes at two measurements is also the full working course of a pedal which has to be 60–65 mm. If the distance from an overlay of the platform of a pedal to a floor does not correspond specified in item 2, adjust it, changing length of a pusher of the vacuum amplifier of brakes.

3. Remove the vacuum amplifier of brakes from the car (see. "Replacement of the vacuum amplifier of brakes").

    

NOTE Need of removal of the amplifier is explained by the fact that on the car there is no access to adjusting knot of a rod of the amplifier.

4. Weaken a lock-nut inhaling 2 adjusting plugs and, holding a rod 3 from a provorachivaniye, rotate the adjusting plug 1 in the necessary party.

NOTE At serviceable the vacuum amplifier and details of pedal knot the optimum full speed of a pedal of a brake is established automatically at installation of the size of 278,5 mm from the case of the amplifier to the center of an opening in a pusher fork (see. "Replacement of the vacuum amplifier").

5. 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 8–10 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 that can be a consequence of wear of a finger of a fork and openings in a fork and a pedal;

– the distance from the platform of a pedal in a free state to a floor is incorrectly adjusted (see item 2).

6. 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!