21:13. Repair of a back support


Fig. 15-30. Back support: 1 – самоконтрящиеся bolts, 35 N · m; 2 – a support with the lever for a cable of the parking brake; 3 – pumping union; 4 – protective cap; 5 – sealing ring; 6 – piston; 7  directing pin; 8, 9 – protective covers; 10 – holder of a support



Details of a back support are presented in fig. 15-30.
Clear a support of dust and dirt, using at the same time a security measure of respiratory organs.

Fig. 15-31. Use of the tool 3272 for a piston vyvinchivaniye from a support



Unscrew the piston from a support by means of the tool 3272 (fig. 15-31). For a vyvinchivaniye of the piston install the tool so that the fillet of the tool was established in piston grooves. Rotate the tool case counterclockwise against the stop. Rotating the tool handle counterclockwise, unscrew the piston from a support.
Accurately take out consolidation from a support cylinder flute, using an assembly wedge or an edge of the flat screw-driver as the lever.
Check a condition of all details of a support, replace the worn-out or damaged details. Pay special attention to the cylinder and the piston. In the presence of scratches, рисок, wear or pointed corrosion replace the piston and the cylinder. Irrespective of a state replace rubber consolidations.
Wash out all details in methyl alcohol or pure brake fluid and wipe them. Blow tubes and openings compressed air.

Fig. 15-21. An installation site of a protective cover on the support piston



Apply a thin film  of A2 G 052 150 lubricant on a sealing ring and the piston (see fig. 15-21).
Install a dustproof cover on the piston so that the internal diameter of a cover was included into a piston flute.

Fig. 15-32. Use of special device for installation of a working edge of a dustproof cover in a support



Install the piston opposite to the cylinder of a support and, using special adaptation, insert a working edge of a dustproof cover into a support before its fixing (fig. 15-32).
Screw in the piston in a support by means of the tool 3272. For a vvinchivaniye of the piston install the tool so that its fillet entered piston grooves. Rotate the tool case counterclockwise against the stop. Rotating the tool handle clockwise, screw in the piston in a support (see fig. 15-31).
After installation of the piston, it is necessary to blow air the cylinder and to fill it with fresh brake fluid.