Each 15 000 km of run of the car or once a year check thickness of lobbies and back overlays of brake shoes.

Disk brakes

Check of wear of overlays of brake shoes of disk brakes carry out in the following order:

visually estimate thickness of brake shoes. If necessary use a portable lamp and a small mirror.

if visual survey is complicated, remove wheels;

measure thickness of external brake shoes together with the metal basis of a block. Thickness of internal brake shoes define visually;

brake shoes of lobbies and back disk brakes reach a wear limit if their thickness makes 7 mm together with the metal basis of a block. In this case all brake shoes on one axis are subject to replacement.

NOTE Under the most adverse service conditions of the car wear of brake slips makes no more than 1 mm on 1000 km of run of the car. At normal operation of the car the resource of work of brake shoes makes not less than 30 000 km of run of the car.

Drum-type brakes

Check of wear of overlays of brake shoes of drum-type brakes carry out in the following order:

Fig. 12.2. An arrangement of the stopper closing a viewing opening, on a brake board

remove a stopper of a viewing opening from the interior of a brake board (fig. 12.2) ;

by means of a portable lamp visually estimate thickness of a brake slip;

if the thickness of any slip decreased to 2,5 mm, replace all back brake shoes;

check, whether there are no traces of oil and brake liquid on blocks.