Master Cylinder Replacement
REMOVECAUTION: On ABS equipped vehicles, vacuum in power booster must be pumped down before removing master cylinder to prevent booster from sucking in any contamination. This can be done simply by pumping the brake pedal until a firm pedal is achieved, with the ignition off.
1. On ABS equipped vehicles, be sure engine is not running, and pump the brake pedal until a firm pedal is achieved (4 - 5 strokes).
Master Cylinder Fluid Level Sensor:
2. Remove vehicle wiring harness connector, from brake fluid level sensor, in master cylinder brake fluid reservoir.
Primary And Secondary Brake Tubes Without ABS Brakes:
Primary And Secondary Brake Tubes With ABS Brakes:
3. Disconnect the primary and secondary brake tubes from the master cylinder. Install plugs at all open brake tube outlets on master cylinder assembly.
4. On vehicles equipped with ABS, clean area where master cylinder attaches to booster using a suitable brake cleaner product such as Mopar Brake Parts Cleaner or an equivalent.
Master Cylinder Mounting To Vacuum Booster:
5. Remove the 2 nuts attaching master cylinder housing to power brake vacuum booster.
6. Slide master cylinder assembly straight out of the power brake vacuum booster.
Removing Seal From Vacuum Booster:
CAUTION: On vehicles equipped with ABS, the master cylinder is used to create the seal for holding vacuum in the power brake vacuum booster. The vacuum seal in the front of the power brake vacuum booster MUST be replaced whenever the master cylinder is removed from the power brake vacuum booster.
7. If vehicle is equipped with ABS, remove vacuum seal located in the front of the power brake vacuum booster. Vacuum seal is removed by carefully inserting a small screw driver between the push rod of the power brake vacuum booster and vacuum seal and pry seal out of power brake vacuum booster. Do not attempt to pry seal out of master cylinder by inserting a tool between seal and power brake vacuum booster.
INSTALL
CAUTION:
- When replacing the master cylinder on a vehicle equipped with ABS, a NEW vacuum seal MUST be installed in the power brake vacuum booster. Use only the procedure detailed below for installing vacuum seal into power brake vacuum booster. Be sure old vacuum seal is removed from power brake vacuum booster before attempting to install new seal.
- When lubricating master cylinder push rod, use only Mopar Silicone Dielectric Compound. Using any other type of grease or lubricant on the push rod, will not provide adequate long term lubrication of the push rod.
Lubricating Master Cylinder Push Rod:
1. Lubricate master cylinder push rod as indicated only using Mopar Dielectric Grease And No Substitutes. Refer to the Mopar Chemicals Catalog to obtain the required lubricant.
Fig 19 Type 3 Vacuum Seal Installation. Neon Models Equipped With ABS:
Fig 20 Type 3 Vacuum Seal Seating. Neon Models Equipped With ABS:
2. Install vacuum seal on master cylinder push rod as shown with notches on vacuum seal pointing toward master cylinder housing. Then slide vacuum seal onto master push rod until seal is seated against master cylinder housing before installing master cylinder on power brake vacuum booster.
CAUTION: If vehicle is equipped with ABS, be sure old vacuum seal is removed from power brake vacuum booster before attempting to install master cylinder and NEW vacuum seal. If vacuum seal is not removed, refer to Master Cylinder Removal in this section of the service manual for required vacuum seal removal procedure.
3. Position master cylinder on studs of power brake unit, aligning push rod on power brake vacuum booster with master cylinder push rod.
4. Install the 2 master cylinder to power brake unit mounting nuts and torque to 28 Nm (250 inch lbs.) torque.
5. Connect brake tubes to master cylinder primary and secondary ports. Torque all tube nuts to 17 Nm (145 inch lbs.) torque.