REMOVAL & INSTALLATION
See Figures 1 through 11
On vehicles equipped with ABS, vacuum in the power booster must be pumped down before removing the master cylinder, in order to prevent the booster from sucking in any contamination. You can do this by pumping the brake pedal until a firm pedal is attained, with the ignition ON.
- Disconnect the negative battery cable.
- If equipped with ABS, pump the brake pedal about 9-10 times, until a firm pedal is achieved.
- Using a vacuum pump or clean turkey baster, remove as much fluid as possible from the master cylinder reservoir.
- Detach the electrical connector from the brake fluid level sensor in the master cylinder fluid reservoir.
- Disconnect the primary and secondary brake lines from the master cylinder, then plug all of the brake tube outlets to prevent contamination from entering the brake system.
- If equipped with ABS, use a suitable cleaner and a rag to clean to area where the master cylinder attaches to the booster.
- Unfasten the 2 nuts securing the master cylinder housing to the power brake vacuum booster.
On ABS equipped vehicles, the master cylinder is used to form the seal for holding vacuum in the power brake vacuum booster. The vacuum seal in the front of the booster MUST be replaced whenever the master cylinder is removed from the power brake vacuum booster.
- If equipped with ABS, remove the vacuum seal found in the front of the power brake vacuum booster. The vacuum seal is removed by carefully installing a small prytool between the pushrod of the power brake vacuum booster and vacuum seal, then prying the seal from the booster. Do not try the pry the seal from the master cylinder by inserting a tool between the seal and power brake vacuum booster.
When installing the master cylinder on a vehicle that has ABS, a new vacuum seal must be installed in the power brake vacuum booster. Use only the following procedure to install the seal. Make sure the old seal is removed from the booster before trying to install a new seal.
- Lubricate the entire surface of the master cylinder pushrod with Mopar silicone dielectric compound, or equivalent.
- Install the vacuum seal on the master cylinder pushrod, as shown in the accompanying figure, with the notches on the vacuum seal pointing toward the master cylinder housing. Then slide the seal onto the master pushrod until the seal is seated against the master cylinder housing before installing the master cylinder on the booster.
- Position the master cylinder on the studs of the power brake unit, aligning the pushrod on the power brake vacuum booster with the master cylinder pushrod.
- Install the master cylinder-to-power brake unit mounting nuts and tighten to 21 ft. lbs. (28 Nm).
- Unplug, then connect the brake lines to the master cylinder primary and secondary ports. Tighten all of the tube nuts to 12 ft. lbs. (17 Nm).
- Attach the electrical connector to the brake fluid level sensor in the master cylinder fluid reservoir.
- Connect the negative battery cable.