72 240z, front brake system questions

[BTF/PTM]

Hi all,

 

First off, I did read the really well-done thread on all the possible brake system swaps out there, so don't worry my questions aren't in regard to what calipers will fit or whether I should use slotted rotors.

 

I'm picking up a 72 datsun 240z tomorrow, and it's equipped with a 15/16" master cylinder and otherwise stock brakes. Of course, the brakes feel weak with the oversize cylinder pushing against stock calipers. I'm leaning toward installing a pair of 78-84 toyota truck calipers to balance it out, but I'm also wondering if I should have the vacuum booster checked out as well and possibly replaced since it's probably original. Anyone have feedback on this issue?

[lowrider]

Hi all,

 

First off, I did read the really well-done thread on all the possible brake system swaps out there, so don't worry my questions aren't in regard to what calipers will fit or whether I should use slotted rotors.

 

I'm picking up a 72 datsun 240z tomorrow, and it's equipped with a 15/16" master cylinder and otherwise stock brakes. Of course, the brakes feel weak with the oversize cylinder pushing against stock calipers. I'm leaning toward installing a pair of 78-84 toyota truck calipers to balance it out, but I'm also wondering if I should have the vacuum booster checked out as well and possibly replaced since it's probably original. Anyone have feedback on this issue?

Im running the 15/16 master cylinder with the stock brakes on my 260 currently(4x4 fronts and rear disks planned for the future). The braking effort is next to nothing, I would definetly check the booster. It should be the cause of the "weak brake feel" as long as the rest of the braking system is up to par.

Edited March 4, 2010 by lowrider

[BTF/PTM]

Thanks! The braking system feels good other than being overall weak. No drags or pulls to one side or the other, no shakes or squeals, so on and so on. I'll check into the booster, maybe have a local shop look at it. Hopefully they're not outrageously expensive to replace, but on a 39-year-old car I guess it's something that may need to be done.

 

Im running the 15/16 master cylinder with the stock brakes on my 260 currently(4x4 fronts and rear disks planned for the future). The braking effort is next to nothing, I would definetly check the booster. It should be the cause of the "weak brake feel" as long as the rest of the braking system is up to par.

Edited March 4, 2010 by BTF/PTM

[BTF/PTM]

An update, the problem is in fact a dead vacuum booster. I had it checked at a local Z car specialist (Z Whizz Auto). They did also say that the rest of the brake system is in tip-top shape, so after a rebuild of the booster the car should be good to go as far as brakes.

 

It will be interesting to see how well the car stops with the fresh booster - I wouldn't want to do a hard emergency stop as they were, but the car stopped safely and predictably during normal driving conditions without any boost at all.