Nissan Pick-ups and Pathfinder 1970-1988

Master Cylinder

Print


CAUTION
Brake shoes contain asbestos, which has been determined to be a cancer causing agent. Never clean the brake surfaces with compressed air! Avoid inhaling any dust from any brake surface! When cleaning brake surfaces, use a commercially available brake cleaning fluid.

REMOVAL & INSTALLATION



See Figures 1, 2, 3 and 4


CAUTION
Be careful not to spill brake fluid on the painted surfaces of the vehicle; it will damage the paint.

  1. Unfasten the hydraulic lines from the master cylinder. On early models, disconnect the lines running to the master cylinder reservoir.
  2.  
  3. Disconnect the hydraulic fluid pressure differential switch wiring connectors. On models with fluid level sensors, disconnect the fluid level sensor wiring connectors, as well.
  4.  
  5. Loosen the master cylinder reservoir mounting bolts.
  6.  
  7. Then do one of the following:
    1. On models with manual brakes, remove the master cylinder securing bolts and the clevis pin from the brake pedal. Remove the master cylinder;
    2.  
    3. On models with power brakes, unfasten the nuts and remove the master cylinder assembly from the power brake unit.
    4.  

  8.  

To install:
  1. Install the master cylinder and note the following:
    1. Certain models may have an UP mark on the cylinder boot, make sure this is in the correct position.
    2.  
    3. Before tightening the master cylinder mounting nuts or bolts, screw the hydraulic line into the cylinder body a few turns.
    4.  
    5. After installation is completed, bleed the master cylinder and the brake system.
    6.  
    7. Check and adjust the brake pedal.
    8.  

  2.  



Click image to see an enlarged view

Fig. Fig. 1: Removing the electrical connection from the master cylinder



Click image to see an enlarged view

Fig. Fig. 2: Removing the brake lines from the master cylinder, note tool used for this procedure



Click image to see an enlarged view

Fig. Fig. 3: Removing the master cylinder mounting bolts



Click image to see an enlarged view

Fig. Fig. 4: Removing the master cylinder assembly

OVERHAUL



See Figures 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 and 24

  1. Place the cylinder securely in a vise. Remove the reservoir caps and floats. Unscrew the bolts which secure the reservoir(s) to the main body.
  2.  
  3. Remove the pressure differential warning switch assembly. Then, working from the rear of the cylinder, remove the boot, snapring, stop washer, piston No. 1, spacer, cylinder cup, spring retainer, and spring, in that order.
  4.  
  5. Remove the end plug and gasket from the front of the cylinder (if equipped), and then remove the front piston stop bolt from underneath. Pull out the spring, retainer, piston No. 2, spacer, and the cylinder cup.
  6.  
  7. Remove the two outlet fittings, washers, check valves and springs.
  8.  
  9. Remove the piston cups from their seats only if they are to be replaced.
  10.  

After washing all parts in clean brake fluid, dry them with compressed air (if available). Drying parts with a shop rag can deposit lint and dirt particles inside the assembled master cylinder. Inspect the cylinder bore for wear, scuff marks, or nicks. Cylinders may be honed slightly, but the limits is 0.15mm. In view of the importance of the master cylinder, it is recommended that it is replaced rather than overhauled if worn or damaged.

  1. Absolute cleanliness is essential. Coat all parts with clean brake fluid prior to assembly.
  2.  
  3. Bleed the hydraulic system after the master cylinder is installed.
  4.  



Click image to see an enlarged view

Fig. Fig. 5: Exploded view of the master cylinder - 1972-77



Click image to see an enlarged view

Fig. Fig. 6: Exploded view of the master cylinder - 1978-80



Click image to see an enlarged view

Fig. Fig. 7: Exploded view of the master cylinder - 1981-86 (720D series)



Click image to see an enlarged view

Fig. Fig. 8: Exploded view of the master cylinder - 1986-88 (D21-D series)



Click image to see an enlarged view

Fig. Fig. 9: Cleaning the master cylinder assembly



Click image to see an enlarged view

Fig. Fig. 10: Removing the reservoir holddown screw



Click image to see an enlarged view

Fig. Fig. 11: Removing the reservoir from the master cylinder



Click image to see an enlarged view

Fig. Fig. 12: Removing the brake reservoir seat from the master cylinder



Click image to see an enlarged view

Fig. Fig. 13: Removing the stopper ring from the master cylinder



Click image to see an enlarged view

Fig. Fig. 14: Removing the primary piston assembly from the master cylinder



Click image to see an enlarged view

Fig. Fig. 15: Removing the stopper bolt



Click image to see an enlarged view

Fig. Fig. 16: View of the stopper bolt removed from the master cylinder



Click image to see an enlarged view

Fig. Fig. 17: Removing the secondary piston assembly from the master cylinder



Click image to see an enlarged view

Fig. Fig. 18: View of the master cylinder disassembled



Click image to see an enlarged view

Fig. Fig. 19: Removing the piston assembly



Click image to see an enlarged view

Fig. Fig. 20: Removing the return spring seat from the piston



Click image to see an enlarged view

Fig. Fig. 21: Removing the spring seat from the piston



Click image to see an enlarged view

Fig. Fig. 22: View of the piston assembly



Click image to see an enlarged view

Fig. Fig. 23: Removing the piston cup



Click image to see an enlarged view

Fig. Fig. 24: View of the master cylinder piston assemblies

 
label.common.footer.alt.autozoneLogo