Bench Bleeding

WARNING
Replacement master cylinders are delivered dry. To prevent damage to the pistons in the master cylinder, all new master cylinders should be bench bled prior to installation. Bleeding a new master cylinder on the vehicle is not a good idea. With air trapped inside, the master cylinder piston may bottom in the bore and possibly cause internal damage.

1. Secure the master cylinder in a bench vise using soft jaws.
2. Remove the master cylinder reservoir cap.
3. Manufacture or purchase bleeding tubes and install them on the master cylinder as illustrated.

   NOTE: The bleeding tubes are installed on the master cylinder then curved to drain into the reservoir.

4. Fill the master cylinder reservoir with clean, fresh brake fluid until the level is within 0.25 in. of the reservoir top.

   NOTE: Ensure the bleeding tubes are below the level of the brake fluid, otherwise air may get into the system making your bleeding efforts ineffective.

5. Use a blunt tipped rod (a long socket extension or Phillips head screwdriver works well) to slowly depress the master cylinder piston. Make sure the piston travels its full stroke.
6. As the piston is depressed, air bubbles will exit the bleeding tubes. Continue depressing and releasing the piston until all bubbles cease.
7. Refill the master cylinder with fluid.
8. Remove the bleeding tubes.
9. Install the master cylinder reservoir cap.
10. Install the master cylinder on the vehicle.