15/16 upgraded master cylinder for 240z, 260z, 280z
This is a new 15/16 master cylinder. Many people who have after market brake kits installed on their cars use this master cylinder to compensate for the added piston area that has to be accounted for. This upgrade will make your brake pedal have less play when adjusted correctly. It is a 14% percent increase in brake fluid. Stock 240z-280z use a 7/8 master cylinder. If you are planning on getting upgraded brakes this is a recommended part for ideal performance.
Note:
Reservoirs and caps are not included, but the stock 240z-280z reservoirs will fit perfectly. You need to remove the drum brake constant pressure valves from the front and rear hard line outlets of the master cylinder! See pictures. These are black rubber pieces. Take off hardline threaded nuts from bottom of the master cylinder. Then remove cone-shaped metal piece. Then you will see the rubber valve. Remove rubber valve and replace the metal cone, then threaded hardline nut. These valves cause constant hydraulic pressure in the brake line which is not needed for non-drum brakes.
Which master cylinder is better Wilwood 1 inch or 15/16? Personally I Always recommend the 15/16! It has a better bias between front and rear brakes than the Wilwood 1 inch. The pedal feels like stock when combined with upgraded front and rear brakes. The 15/16 MC will bolt on to the s30, while the Wilwood 1" requires modifications. Wilwood 1" makes the pedal to stiff with less play.