21:11. Repair of a forward support of HP-2

Fig. 15-23. Forward support of HP-2: 1 – protective cap; 2 – pumping union; 3 – support bracket case; 4 – sealing ring; 5 – piston; 6 – protective cover

Details of a forward support of HP-2 are shown in fig. 15-23.

Both parts of the case of a bracket of a support are connected by bolts to internal shaped deepening and are not subject to dismantling. At damage of protective covers of the directing fingers they need to be replaced with new.
Sealing rings are removed with use of an assembly wedge, and are established by a hand.

Clear a support of dust and dirt, at the same time do not inhale the kicked-up dust.
Fix a support in a vice. For extraction of the piston give air under low pressure to the brake cylinder through an opening for connection of a brake hose. From one piston install the special device for cave-in of the piston which will hold the piston on the place, and from the second piston establish wooden whetstone.

Fig. 15-24. Use of an assembly wedge for extraction of consolidation from a support cylinder flute

Remove wooden whetstone and carefully take the piston. Accurately, not to damage a wall of the cylinder take out consolidation from a support cylinder flute an assembly wedge or an edge of the flat screw-driver as the lever (fig. 15-24).
Check a condition of the cylinder and 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.

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. 15-25. 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 by means of special adaptation insert a working edge of a dustproof cover into a support before its fixing (fig. 15-25).
Special adaptation or the handle of the hammer press the piston into the support cylinder.
After installation of the piston blow air the cylinder and fill it with fresh brake fluid.
In need of replacement of the second piston repeat operations on extraction and installation of the piston of a support, at extraction of the piston establish wooden whetstone from the second piston.