7.2.8. Check of a brake disk

Slowly turning a brake disk, visually check up its condition from two parties on absence of cracks, especially round apertures under bolts of fastening of a wheel, and also on deterioration or mechanical damages; if necessary, replace it.

Fig. 7.6. Measurement of a thickness of a brake disk by a micrometer

Measurement of a thickness of a brake disk should be spent in four or more points located on a circle of a disk (fig. 7.6). All measurements carry out on identical distances from disk edge.

If the thickness of a brake disk is less 10 mm, replace a brake disk. In the course of manufacture rigid admissions for a surface of contact of a brake disk with an overlay and lateral palpation are established. Preservation of the rigid admission on a surface of contact to an overlay is necessary for prevention of sharp braking.

According to these admissions the surface roughness should remain the identical. The control of a roughness of a rubbing surface of a brake disk is necessary for avoidance дерганья and unstable braking, and also for increase in durability of a brake overlay.

Fig. 7.7. Use of the indicator of hour type for check of palpation of a brake disk

The indicator of hour type check up palpation of a brake disk. The indicator of hour type fix in any convenient place. Turning a brake disk, define its palpation on distance of 10 mm from external edge (fig. 7.7). Before check of palpation of a brake disk be convinced that the nave bearing in a good condition. Maximum permissible palpation of a brake disk — 0,05 mm.