240z with 280zx brake booster

[skerry]

I bought a 240z locally here a couple of weeks ago and the only problem mechanically seems to be the brake booster. A buddy of mine has a brand new 280zx booster and master cylinder. It's free and the 240z ones seem to be difficult to find so I thought I would check around to see if it was possible. All I've really found on the subject is the following statement:

 

"The original poster is wanting to put a ZX booster in his 1975 Z (_not_ a 1972 Z).

So, I think a little information is needed...

The early (1970-73) Z’s have a different firewall bolt pattern for the brake booster than the later Z’s. Reason being that when the 2+2 version appeared in 1974 a larger diameter booster was needed for the 2+2. This larger booster also resulted in Nissan having to move the move the firewall components slightly for additional clearance and a new foot pedal mounting bracket had to be designed.

This larger booster has a different (larger) bolt pattern than the 240Z’s booster. Nissan elected to keep the same firewall bolt pattern even for the 1974-78 two-seater Z’s which used a smaller diameter booster than the 2+2's.

The 280ZX’s also used this same bolt pattern but the booster rear push rod tube is offset from the bolt centerline in a different direction than the 1974-78 booster. So, as a result you must rotate the ZX booster 180 degrees so that it lines up with the holes in the 1974-78 firewall.

The only way to mount the ZX booster into the early Z (1970-73) cars is by re-drilling the firewall. But this allows you to mount it without rotation." ZCARNUT

 

Now in that last line, does he mean re-drill the bolt holes or does he mean completely redrill the entire hole? Any input would be greatly appreciated.

 

Thanks

Stephen
 

 

[dexter72]

I would try looking for an earlier booster, some members may have one on hand for a decent price.

 

If you can't locate one, make a template from the zx booster mounting holes and place it on your 240 firewall and drill away.

[zcarnut]

> The only way to mount the ZX booster into the early Z (1970-73) cars is by re-drilling the firewall. But this allows you to mount it

> without rotation." ZCARNUT

 

Now in that last line, does he mean re-drill the bolt holes or does he mean completely redrill the entire hole? Any input would be greatly appreciated.

 

 

 

I meant that four new holes would have to be drilled. And its not just the firewall that needs to be re-drilled. The pedal support bracket must also be drilled.

[Miles]

There are several threads in the brake and brake FAQ forums that explain, in detail,  several booster swaps including this one.