Nissan Z - ZX 1970-1988 Repair Guide

Master Cylinder

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REMOVAL & INSTALLATION



See Figures 1, 2, 3, 4 and 5

  1. On the ZX models, remove the heat shield plate.
  2.  
  3. Remove the brake fluid from the reservoir.
  4.  
  5. Disconnect the wiring to the brake fluid level gauge at the electrical connector. Early models do not have the gauge.
  6.  
  7. Place some shop cloths under the master cylinder to catch the spilled fluid.
  8.  
  9. Using a flare nut wrench, unbolt the brake tubes from the master cylinder.
  10.  


WARNING
Brake fluid will damage the paint; wipe up any spilled fluid immediately, then flush the area with clear water.

  1. Cap the brake tubes.
  2.  
  3. Remove the master cylinder-to-vacuum booster nuts and the master cylinder from the vehicle.
  4.  
  5. To install, place the master cylinder into position. and tighten the master cylinder-to-vacuum booster nuts to 5.0-8.0 ft. lbs. (6.8-10.8 Nm).
  6.  



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Fig. Fig. 1: Remove the screen from inside the reservoir and remove as much brake fluid as possible



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Fig. Fig. 2: Unfasten the harness from the side of the reservoir



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Fig. Fig. 3: Use a flare wrench to loosen and remove the brake lines from the master cylinder



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Fig. Fig. 4: Remove the retaining nuts securing the master cylinder to the brake booster



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Fig. Fig. 5: Slide the master cylinder off the studs, and out of the engine compartment

To install:
  1. Reconnect the brake lines and tighten to 11-13 ft. lbs. (15-18 Nm).
  2.  
  3. Reconnect the wiring to the gauge, if so equipped.
  4.  
  5. On ZX models, install the heat shield.
  6.  
  7. Bleed the brake system and check for leaks. Adjust the brake pedal height, if necessary.
  8.  

OVERHAUL



See Figures 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and 20

This is a tedious, time consuming job. A lot of trouble can be saved by buying a rebuilt master cylinder from your dealer or a parts supply house. The small difference in cost between a rebuilding kit and a rebuilt part usually makes it more economical, in terms of time and work, to buy the rebuilt part.

Datsun/Nissan has two suppliers of brake parts: Nabco and Tokico. These parts are not interchangeable. Be certain to get the correct rebuilding parts for the vehicle's master cylinder. The manufacturer's name is clearly stamped on the part.

  1. Remove the master cylinder from the vehicle.
  2.  
  3. Remove the reservoir caps and filters, then drain the brake fluid. Discard this fluid.
  4.  
  5. Using a small prybar, carefully pry the piston stopper snapring from the open end of the master cylinder.
  6.  
  7. Remove the stopper screw and the washer from the bottom of the master cylinder, then the primary and secondary piston assemblies from the master cylinder bore.
  8.  
  9. Remove the caps on the underside of the master cylinder to gain access to the check valves, for cleaning.
  10.  

DO NOT disassemble the brake fluid level gauge, if equipped.

  1. Discard all the used rubber parts and gaskets. These parts should be replaced with the new components included in the rebuilding kit.
  2.  

DO NOT remove the master cylinder reservoir tanks unless they are leaking. If they are removed for any reason, they must be replaced with new ones.

  1. Clean all the parts in clean brake fluid. DO NOT use mineral oil or alcohol for cleaning.
  2.  
  3. Check the cylinder bore and piston for wear, scoring, corrosion or any other damage. The piston and cylinder bore can be dressed with crocus cloth soaked in brake fluid. Move the crocus cloth around the cylinder bore, not in and out. Do the same to the piston, if necessary. Wash both the cylinder bore and the piston with clean brake fluid.
  4.  
  5. Check the piston-to-cylinder bore clearance; it should measure less than 0.15mm for all models. If a larger clearance exists, replace the piston, the cylinder or both. The cylinder bore diameter should be 0.867 in. (22.23mm) for 1970-78 models or 0.929 in. (23.81mm) for 1979-88 models.
  6.  
  7. Soak all of the components in clean brake fluid before assembling them.
  8.  
  9. Reassemble the the master cylinder as outlined in the rebuilding kit.
  10.  
  11. Clamp the master cylinder in a vise by one of its flanges. Fill the reservoirs with fresh fluid and pump the piston with a screwdriver until fluid squirts from the outlet ports. Install the master cylinder and bleed the system.
  12.  



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Fig. Fig. 6: Pry the stopper cap retaining tab from the master cylinder-1987 model shown



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Fig. Fig. 7: With the tab pried up, the stopper cap can be removed



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Fig. Fig. 8: Use a rag to capture any remaining fluid



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Fig. Fig. 9: Remove the primary piston assembly from the bore



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Fig. Fig. 10: Remove the secondary piston and spring



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Fig. Fig. 11: Removing the primary piston seal with a pick tool



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Fig. Fig. 12: Disassembling the primary piston



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Fig. Fig. 13: Disassembled 1984-88 master cylinder and components



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Fig. Fig. 14: Exploded view of 1970-72 master cylinder



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Fig. Fig. 15: Exploded view of 1973-78 master cylinder



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Fig. Fig. 16: Exploded view of NABCO master cylinder-1979-81 models



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Fig. Fig. 17: Exploded view of TOKICO master cylinder-1979-81 models



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Fig. Fig. 18: Exploded view of NABCO master cylinder-1982-83 models



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Fig. Fig. 19: Exploded view of TOKICO master cylinder-1982-83 models



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Fig. Fig. 20: Exploded view of 1984-88 master cylinder

 
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