3.1.7. Dismantling, check and assembly of the working cylinder of coupling

Unscrew a bolt of fastening of the working cylinder.

Check the working cylinder on existence of leakages of liquid.

Check a cover of the working cylinder on existence of damages.

Disconnect from the cylinder a connecting hose, remove a valve plate, a spring, a pusher and a cover.

Carefully remove dirt round boring of the working cylinder under the piston.

Fig. 3.26. Piston extraction from the cylinder

Take the piston from the cylinder, having submitted to the last compressed air (fig. 3.26).

ATTENTION Previously cover the working cylinder with rags since the piston can take off with big force and cause a trauma. Pressure of air increase gradually to prevent emission of brake liquid and its hit in eyes or on skin.

Check a mirror of the working cylinder on existence of corrosion or damages.

Fig. 3.27. Check of internal diameter of the cylinder by means of a nutromer

By means of a nutromer check internal diameter of the cylinder in three places (in the bottom, average and top parts). If the gap between the piston and the cylinder exceeds maximum permissible value, replace the working cylinder (fig. 3.27).

Maximum permissible gap between the piston and the cylinder: 0,15 mm.

Fig. 3.28. Piston installation in the cylinder

Put brake DOT 3 or DOT 4 liquid on an internal surface of the working cylinder and an external surface of the piston and a cuff of the piston and establish the piston in the cylinder (fig. 3.28).

To establish a valve plate, a pusher and a cover.

Fig. 3.29. Pusher axis

Put on a pusher axis greasing of demanded brand (fig. 3.29).

Establish the working cylinder of a drive of coupling and wrap a bolt of fastening of the working cylinder.