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

Turn off a bolt of fastening of the working cylinder.

Check of technical condition
Check the working cylinder for existence of leak of liquid.
Check a cover of the working cylinder for existence of damages.

Dismantling
Disconnect a connecting hose from the cylinder, remove a valve plate, a spring, a pusher and a cover.
Carefully remove dirt around boring of the working cylinder under the piston.

Fig. 3.26. Extraction of the piston from the cylinder


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

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

Check of technical condition
Check a mirror of the working cylinder for 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 the internal diameter of the cylinder in three places (in the lower, 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.

Assembly

Fig. 3.28. Installation of the piston in the cylinder


Apply the DOT 3 or DOT 4 brake fluid on the internal surface of the working cylinder and the external surface of the piston and a cuff of the piston and install the piston in the cylinder (fig. 3.28).
To establish a valve plate, a pusher and a cover.

Installation

Fig. 3.29. Pusher axis


Apply lubricant of the required brand (fig. 3.29) on a pusher axis.
Install the working cylinder of the drive of coupling and wrap a bolt of fastening of the working cylinder.