Originally Posted by Lip Ripper
I have a 70 240Z. When going through the brake system I had to use a MC and rear wheel cylinders from the late 71 up because the OE parts aren't available. I will say that the plungers were different on the MC but I read that they'll work and it did. I noticed the other day, when I hit the brake pedal the rpm's went up. That's telling me the booster is leaking. So my question is can I just order one for the 72 model? That way the booster and MC are mated properly.
There are actually 3 different boosters for the 240 z. #1
Up to 8/71 production date is the first style, #2
8/71-6/72 is the second series, #3
7/72-6/78 coupes is used after that. #1
are interchangeable and use the identical bolt pattern to the firewall. The #3
unit uses a totally different bolt pattern and will not interchange with the earlier models without drilling new holes and reinforcing the firewall accordingly. The #1
unit uses a shorter pushrod tip, I don't remember the length of the #2
unit, and the #3
unit is definitely longer. The tips of the pushrods unscrew and are interchangeable. If you put a 72-78 master cylinder on a series 1 booster, it will not fully engage the master cylinder giving you a weak brake pedal and is dangerous of course. The rear wheel cylinder breakdown is #1
fits up to cars with a pro date of 6/72. From 7/72-7/76 you have to go to the series #2
wheel cylinder. The difference between the two is the position of the hard line or brake bridge screwing into the wheel cylinder. If you have the proper tools, you can rebend the brake bridge to interchange, otherwise you'd have to get the newer brake bridge. Major difference in price between the 2 different models of wheel cylinders. For those of you that don't know, the rear wheel cylinders are identical between left and right sides of their corresponding models, only the hardware is different. That would be the parking brake bracket and the adjuster wheel so as long as you installed the correct hardware, the wheel cylinders themselves will fit either side.
Z man of Washington