Chrysler Front Wheel Drive Cars 4-CYL 1981-1995 Repair Information

Master Cylinder

Print

REMOVAL & INSTALLATION




WARNING
On vehicles equipped with a Bendix Type 6 Anti-lock Brake System (ABS), a Diagnostic Readout Box (DRB or DRB II) is necessary for brake system bleeding. Failure to use a DRB to bleed the system will lead to system failure. Refer to the ABS portion of this section for bleeding procedures and precautions.

Except Premier
NON-POWER BRAKES
  1. Disconnect the primary and secondary brake lines and install plugs in the master cylinder openings.
  2.  
  3. Disconnect the stoplight switch mounting bracket from under the instrument panel. Pull the stop light switch out of the way to prevent switch damage.
  4.  
  5. Pull the brake pedal backward to disengage the pushrod from the master cylinder piston.
  6.  

The grommet will break during removal. Be sure to use a new grommet during installation.

  1. Remove the master cylinder-to-firewall nuts.
  2.  
  3. Slide the master cylinder out and away from the fire wall. Be sure to remove all pieces of the broken grommet.
  4.  

To install:
  1. Install the boot on the pushrod.
  2.  
  3. Install a new grommet on the pushrod.
  4.  
  5. Apply a soap and water solution to the grommet and slide it firmly into position in the primary piston socket. Move the pushrod from side to side to make sure it's seated.
  6.  
  7. From the engine side, press the pushrod through the master cylinder mounting plate and align the mounting studs with the holes in the cylinder.
  8.  
  9. Install the nuts and torque them to 250 inch lbs.
  10.  
  11. From under the instrument panel, place the pushrod on the pin on the pedal and install a new retaining clip. Be sure to lubricate the pin.
  12.  
  13. Install the brake lines on the master cylinder.
  14.  
  15. Bleed the system.
  16.  

POWER BRAKES-WITHOUT ABS

See Figures 1, 2, 3 and 4

Click image to see an enlarged view

Fig. Fig. 1: Before removing the master cylinder, withdraw as much of the brake fluid as possible, ...



Click image to see an enlarged view

Fig. Fig. 2: ... then loosen and remove the brake line fittings from the master cylinder outlet ports



Click image to see an enlarged view

Fig. Fig. 3: Remove the master cylinder mounting nuts from the vacuum booster studs and ...



Click image to see an enlarged view

Fig. Fig. 4: ... pull the master cylinder off of the vacuum booster

  1. Disconnect the primary and secondary brake lines from the master cylinder. Plug the openings.
  2.  
  3. Remove the nuts attaching the master cylinder to the power brake booster.
  4.  
  5. Slide the master cylinder straight out, away from the booster.
  6.  

To install:
  1. Before installing the replacement master cylinder on the vehicle, it is a good idea to bench bleed the master cylinder. This will reduce the amount of system bleeding needed after installation is complete.
  2.  
  3. Position the master cylinder onto the power booster studs, align the push rod with the master cylinder piston, then install the mounting nuts.
  4.  
  5. Tighten the mounting nuts to 21 ft. lbs. (28 Nm).
  6.  
  7. Connect the brake tubes to the master cylinder primary and secondary ports. Tighten the fittings to 13 ft. lbs. (17 Nm).
  8.  
  9. Bleed the brake system. For more details, refer to the brake system bleeding procedure located later in this section.
  10.  

POWER BRAKES-WITH ABS

For the removal and installation of the ABS-equipped master cylinder (hydraulic assembly), refer to the ABS portion of this section.

Premier
WITHOUT ABS

See Figure 5

Click image to see an enlarged view

Fig. Fig. 5: Installing the master cylinder into a Premier

  1. Disconnect the negative battery cable.
  2.  
  3. Unplug the fluid sensor electrical connector, if equipped.
  4.  
  5. Disconnect and plug the brake lines. Cover the master cylinder outlet ports and brake lines to prevent the entry of dirt.
  6.  
  7. Remove the master cylinder retaining bolts or nuts.
  8.  
  9. Remove the proportioning valve bracket, if required.
  10.  
  11. Remove the master cylinder from the vehicle.
  12.  

To install:
  1. Before installing the replacement master cylinder on the vehicle, it is a good idea to bench bleed the master cylinder. This will reduce the amount of system bleeding needed after installation is complete.
  2.  
  3. Position the master cylinder on the power booster mounting studs and seat the cylinder onto the booster.
  4.  


WARNING
Be sure that the booster push rod is seated in the master cylinder primary piston before seating the cylinder completely on the booster. Also take care to avoid damaging the primary piston surface during installation. Internal leakage will occur if the piston surface is scratched or scraped.

  1. Install the master cylinder onto the vacuum booster first, then install the proportioning valve bracket onto the studs. Start the master cylinder attaching nuts onto the studs just far enough to the cylinder and bracket on, but the master cylinder should remain moveable on the studs.
  2.  
  3. Connect and tighten the brake lines to the master cylinder and the proportioning valve.
  4.  
  5. Tighten the master cylinder-to-vacuum booster stud attaching nuts to 11 ft. lbs. (15 Nm).
  6.  
  7. Fill the master cylinder with fresh brake fluid (if not previously bench bled), then bleed the entire brake system.
  8.  

Do not only bleed the master cylinder; the entire brake system MUST be bled to ensure that all trapped air is removed from the hydraulic system.

  1. Installation is the reverse of the removal procedure.
  2.  
  3. The entire brake system must be bled after installing the master cylinder.
  4.  

WITH ABS

For the removal and installation procedures for the master cylinder (hydraulic assembly) on ABS vehicles, please refer to the ABS portion of this section.

BLEEDING



See Figure 6

Click image to see an enlarged view

Fig. Fig. 6: When bleeding the master cylinder, make sure that the outlet fittings are tight and that the hoses are below the fluid level-use a dowel to depress the master cylinder plunger

A master cylinder bleeding kit or 2 pieces of brake tubing (with a fitting on at least one end) will be needed for this procedure.

  1. Place the removed master cylinder in a bench-mounted vise.
  2.  
  3. If using the master cylinder bleeding kit, install the two hoses into the master cylinder outlet ports. Position the other ends in the master cylinder reservoir.
  4.  
  5. If using the two pieces of brake line, bend the brake lines so that when installed to the outlet ports of the master cylinder, the other ends of the tubing will be positioned about 1 / 4 in. (6mm) from the floor of the reservoir (the ends are in the reservoir). The tubes will almost form a complete circle shape (as shown in the illustration). Install the tubes to the master cylinder and tighten the fittings.
  6.  
  7. Fill the reservoir with brake fluid. The fluid level must be above the ends of the tubing in the reservoir.
  8.  
  9. Using a wooden dowel, depress the pushrod slowly, then allow the pistons to return to its resting position. Perform this several times (it may take a while) until ALL of the air bubbles are all expelled.
  10.  
  11. Remove the bleeding tubes from the master cylinder and quickly plug the master cylinder outlets.
  12.  
  13. Install the cylinder into the vehicle.
  14.  
  15. Make sure to bleed the entire brake system after master cylinder installation.
  16.  

 
label.common.footer.alt.autozoneLogo