Service Procedure

1. Disconnect the negative battery cable.

NOTE:
To enhance customer satisfaction, remember to reset the clock when you have completed the service procedure.

2. Disconnect the brake fluid level sensor wire connector located on the side of the master cylinder reservoir.

3. Disconnect the primary and secondary brake tubes from the master cylinder housing and cap the brake tubes.





4. Remove the 2 nuts attaching the master cylinder to the vacuum booster (Figure 1).

5. Slide the master cylinder straight out from the vacuum booster and remove the master cylinder from the vehicle.

CAUTION:
Do not allow brake fluid to drip out of the master cylinder during removal. Paint damage may occur if brake fluid comes in contact with any painted surfaces.

6. Bleed the new master cylinder using the following procedure:

NOTE:
It is not necessary to bleed the entire hydraulic system after replacing the master cylinder, providing that the master cylinder has been bled and filled prior to installation.

a. Clamp the master cylinder in a soft jawed vise.

CAUTION:
When clamping the master cylinder in a vise for bleeding, carefully tighten the vise just enough to hold the master cylinder from moving. Excessive clamping pressure could damage the master cylinder.





b. Using Special Tool 8129 and 8305, place the open ends of the tubes in the fluid reservoir and attach the bleeding tube fittings to the master cylinder outlet ports (Figure 2).

NOTE:
The master cylinder on this vehicle uses ISO style flares and metric threads on the master cylinder outlet ports.

C. Fill the reservoir with Mopar brake fluid (P/N 04318080) or equivalent. The brake fluid used must conform to DOT 3 specifications.

NOTE:
The open ends of the bleeding tubes must be below the surface of the brake fluid when the reservoir is filled to the proper level.

d. Using a wooden dowel, depress the master cylinder piston slowly, and then allow the piston to return to the released position (Figure 2). Repeat this procedure several times until all the air bubbles are expelled.

e. Remove the bleeder tubes from the master cylinder, plug the outlets and install the filler cap.

7. Install the master cylinder onto the studs of the vacuum booster while aligning the vacuum booster push rod with the master cylinder piston.

8. Install the master cylinder mounting nuts (Figure 1). Tighten the mounting nuts to 250 in. lbs. (28 Nm).

9. Connect the brake tubes to the master cylinder primary and secondary ports. Tighten the fittings to 145 in. lbs. (17 Nm).





10. Connect the brake fluid level sensor electrical connector to the brake fluid level sensor located on the master cylinder reservoir (Figure 3).

11. Depress the brake pedal several times and then recheck the brake fluid level. Add brake fluid until the fluid level reaches the "FULL" mark on the reservoir (Figure 3).

12. Connect the negative battery cable.

13. Verify that there are no brake fluid leaks at the master cylinder and assure proper brake operation.