300Zx brake issues, cant figure it out.

[OutToWinPAHC]

zerothread?id=424409 I posted in Hybrids because I wasn't sure if it was a vacuum issue or not.

But I upgraded from S13 brakes to Z32 brakes around the car right after I cammed the car. At first I had

Used 17/16 Z32 BMCUsed 30mm Iron front calipersNew rear aluminum calipersBone head conversion linesZ32 backing plates and cables

After installing these the brake pedal movement was limited, they felt like manual brakes. So naturally we bled then and then bled them again. Thinking the vacuum was low, I added a Vacuum reserve canister... and still felt the same.

I checked all the lines and hoses, all ok. I even took the vacuum off to see what the felt like and it was worse. I thought it may have been an issue with the BMC so I purchased another rebuilt one.... Still felt the same.

I added a vacuum gauge to my reserve canister..... Constant 14feet even hours after the cars been shut off (check valves are good, system is holding vacuum).

For Sh8ts and giggles I wanted to try a new booster.... my buddy had one on his Silvia front clip that was mint, and the auto abs type so larger. Swapped it and nothing.

Now I don't know what to do. When I bled it from empty after the BMC was swapped the pedal could go to the floor, then after bleeding it only has a movement of 1.5 inch down before stopping.

The only thing left would be to rebuild the calipers I guess. But what do you guys think?

On the thread in the hybrid thread someone said adjusting the booster rod for the new master? I have no idea what else to do, but these brakes feel horrible, I cant get them to lock, the pedal feels horrible almost manual.

Still felt crappy,

[pearl1996zenki]

wow, what a bummer. i have no advice sorry,but this is a horror story and is the only reason i havent done the upgrade. im worryed this exact will happen to myself. il stay with stock brakes for the moment

[rancid240]

Maybe the calipers are on the wrong side? They should be mounted with bleeder side up.

[OutToWinPAHC]

Lol its not that simple. I am going to rebuild them

[JDMZ32]

Why is this in the classifieds?

[OutToWinPAHC]

not a clue, looks as if it was moved, moving back to brakes/wheels.

Issue was vacuum, ended up getting an electric pump.

[gumby74]

The booster rod is the same as the master cylinder. Ther is a turnbuckle at the pedal end that dictates how far the rod travels.

I assume you matched the thread count from the stock booster to the replacement? Just for the record though after swapping from the 1" master cylinder to the larger one I replaced the booster as well. The pedal travel is quite low. I doubt it will go more than 3" with me stomping on it.

[540sx]

I see you went with the electric vacuum.

[crazyandevil05]

I'm having this same problem, been about a year since the swap, same as you except aluminum calipers and rears too. the initial bite is fine, but anything more than a normal need to stop feels like manual brakes. anyway, can you tell me about the electric pump you got? brand, price, etc? thanks!

[crazyandevil05]

Hey, can you give up some info on what pump you got? thanks.

[OutToWinPAHC]

Sorry what engine do you have? Do you know your vacuum?

[crazyandevil05]

rb25

[OutToWinPAHC]

Z32 and R brakes are about the same in operation, I don't think you have a cam / idle issue there.

[Fancy_Footwork]

I'm glad I'm not the only one with this weird issue. I just did the q45 swap for my fronts and have the same problem.

I brake, the car stops, I can even lock the brakes up if I want. However, pedal travel is excessive and there's no feel to them.

About the vacuum pump though, where/what did you get and how is mounted in the vacuum line system?

[OutToWinPAHC]

My pedal travel is fine, you need to adjust your booster rod it sounds like.