Question on upgrade to 1981ZX mastercylinder

I also have a 72 240Z, I just replaced the master cyclinder with the 15/16 MC from a ZX with out changing out the booster. Just check the rod coming out of the brake booster for correct length. I replaced my brake booster at the same time, so I assembled both parts on the garage floor. Be carefull of messing with the rod coming out of the brake booster. If you pull it forward, the rubber disc on the end of the rod will fall inside the booster. Getting it out, can be a bitch Wonder how I know this????

I'm pleased with my braking, but there have been posts that say that you have to push harder on the brake pedal to get the same braking effect you would with the 7/8 MC. Just the distance you push is less.

Rob



Post Edited (Sep 28, 9:15am)

I'm using the toyo calipers with a new OE master cylinder and see no reason to change to the larger one. The ZX one will just make the pedal harder and the pedal travel seems just fine on my car.

Also on many cars with drum brakes, there is a thing called a residual pressure check valve built into the master cylinder to keep a slight amount of pressure on the drum brakes part of the system, which keeps the wheel cylinders from leaking. I've never researched to see if a Z has this or where it is but then again I'm using the stock cylinder so I don't have to think about that! If I was using 4 wheel disks I would go to the ZX master but with rear drums I wouldn't.