79 ZX MC & Booster on 72 240Z

[Miles]

Will a 79 ZX MC and booster work with stock brakes on a 72 240Z? The reason I am asking is that I am planning to upgrade to Toyota calipers and vented rotors on the front and a disk set up on the back. My stock MC is failing so I thought I would just install the ZX MC and booster now. It is my understanding that the ZX booster will work, but has to be mounted upside down.

Thanks

Miles

[Bambikiller240]

I think you'll also have to drill new holes in the firewall to mount it.

[Miles]

Carl

Does the stock 240Z booster work ok with the ZX MC? I'd rather not drill more holes in my firewall.

Miles

[Bambikiller240]

I believe that it does. I've never heard of someone having to swap boosters with the m/c.

Can anyone confirm this from personal experience for Miles?

[LanceM]

From my experiance it won't work. I read in several places that the ZX booster would fit if you mounted it upsidedown. Well let me tell you after taking out my working old one and trying the only way one would fit is edgewise!!! You'll have to do more than drill some holes, the clutch MC is in the way and other things at least on my 73!

BTW, the ZX MC will bolt on to the earlier booster with no changes.

Lance

[Miles]

Lance

Thanks for the info about the booster. The reason I was thinking of going to the ZX booster in my 72 240z was because I have read many posts here and at other sites that people have trouble getting the ZX MC to work with the stock 72 booster. Typically it seems to be a problem with the length of the push rod that goes from the booster into the MC piston cup.

So I am debating if I should replace my leaking stock MC with another stock unit or install the ZX MC now so it will be ready for the Toyta calipers.

Thanks

Miles

[Miles]

I installed a 79 280ZX 15/16 MC in my stock 72 240Z this morning and the brakes are firm. It was a direct swap as the hard pipe connections to the MC were all in the stock position. Pedal feel is good and the brakes come right on.

Miles

[dk240z]

Did you use the ZX booster?

[Miles]

I used the stock 72 240Z booster (Cardone rebuilt). I had to adjust the MC push rod to where it just came in contact with the bottom of the MC piston socket. By the way I inspected the Cardone booster new out of the box and there was no reaction disk to worry about falling out when I adjusted the push rod. The brakes feel solid.

Miles

[redneckz II]

:bandit: You can use the 240Z vacuum system with the early 280ZX MC 15/16"(should have the same mounting bolt system). It is a bolt-up and the only thing you have to adjust, is the rod that runs from the pedal into the MC. You can adjust it to what ever feels good to you. Just make sure you bleed the brakes good after putting it on. The 280ZX MC is backward to the 240Z. You have to bend the brake lines into the MC a short amount. But move the front to the rear and the rear to the front. If I remember right, the 280ZX vacuum system is bigger and will hit the clutch MC. Good luck with it, Rich.

[Jayru]

Hi guys,

Is it nessary to upgrade to the 280zx MC when upgrading to the toyota brakes? Can i just use my stock 72 MC/booster. What are the downsides of this?

Thanks,

Jay

[Miles]

Jay

I have had several people tell me that you don't need to go to the larger bore 280ZX MC. Do a search here and at HybridZ and you will see that some people get away with keeping the stock MC and others who complain that, with the stock MC, the pedal would go the floor after installing the Toyota calipers. I recall some posts where people were pulling their hair out trying to make the stock MC work. This was often compounded by other problems such as a faulty booster, a missing reaction disk, leaks or improper bench bleeding of the MC. It makes sense to me that if you increase the fluid volume requirement by installing the Toyata calipers then the MC must push more fluid hence the need for larger 280ZX MC. The 280ZX MC works good with my stock calipers for now and should work with my Toyota calipers when I install them. Plus the ZX MC is cheaper then the stock MC.

So my advice is if you have the old stock booster, replace it and replace the stock MC with a new 280ZX MC at the same time so you will have no doubt about these components.

Miles