How to Rebuild a 280Z Master Cylinder

All automobile brake systems are hydraulic. A master cylinder consists of a brake fluid reservoir and piston assembly. When the brake is applied, a piston pushes pressurized fluid through brake lines to force the frictional surfaces of the brakes together at each wheel. The Datsun 280Z brake system includes a dual-chamber master cylinder. The smaller reservoir facing the front of the car actuates the rear drum brakes. The larger reservoir nearest the firewall actuates the front disc brakes. This two-reservoir configuration of the front and rear brake systems acts as an added safety measure. In the event that there is a leak, some braking power will remain available.

Instructions

1

Locate the master cylinder in the engine compartment on the driver's side near the firewall.

2

Use a large syringe or turkey baster to siphon the brake fluid from both reservoirs.

3

Disconnect the brake fluid level gauge wiring from both reservoirs.

4

Use a line wrench to disconnect the two brake tubes from beneath the master cylinder.

5

Remove the nuts that secure the master cylinder to the vacuum booster, and pull out the master cylinder.

6

Use snap ring pliers or a small pry tool to remove the snap ring from the open end of the master cylinder.

7

Remove the stopper screw and washer from the bottom of the master cylinder.

8

Remove the primary and secondary piston assemblies from the cylinder bore.

9

Remove the two valve caps and their check valve assemblies from the underside of the master cylinder.

10

Discard used gaskets and rubber parts. They should be replaced with new ones included in the rebuild kit.

11

Clean all the disassembled parts in fresh brake fluid only.

12

Inspect the cylinder bore and piston for scoring, pitting or corrosion. Replace as necessary.

13

Inspect piston cups, check valves and their packing for wear. Inspect springs for wear or deformation. Replace with new ones as necessary.

14

Assemble the master cylinder in reverse order of disassembly.

15

Install the reassembled master cylinder in reverse sequence of removal. Then fill the reservoirs with clean brake fluid. Bleed the brake system of any air and check for leaks.