Removing and Installing Master Cylinder

Master cylinder parts or rebuild kits are not available. Volkswagen specifies that a faulty master cylinder must be replaced. It can be removed and installed with ordinary hand tools. On installation, use a new gasket between the cylinder and the vacuum booster, and new self-locking mounting nuts. Make sure to have an adequate supply of new, unopened brake fluid on hand, as bleeding the brakes will be necessary after installation. See 4.2 Bleeding Brakes..

To remove and install:

1.	Disconnect the battery negative (-) terminal. Disconnect the electrical connector from the brake fluid reservoir cap.

2.	Remove the reservoir cap and, using a clean syringe, empty the brake fluid reservoir.

3.	Disconnect the brake lines from the master cylinder. Remove the two nuts holding the master cylinder to the vacuum booster, then remove the master cylinder. On Golf models, remove the proportioning valves.

4.	If necessary, remove the brake fluid reservoir from the top of the master cylinder by prying it out of the rubber mounting grommets, and install the reservoir on the new master cylinder.

5.	Using a new gasket and self-locking nuts, install the new master cylinder. Torque the nuts to 20 Nm (15 ft. lb.). Connect the brake lines and, on Golf models, the proportioning valves. Torque the valves and the brake line unions to 15 to 20 Nm (11 to 15 ft. lb.).