S13 Brakes Won't Return
 

Hey everyone,

I've got an sr swapped S13 with which appears to be the stock bmc and brake booster. A couple of months back (around November), I've noticed that after stalling the engine, the brake pedal would be very stiff and will not return to its resting position. Recently, I've done a brake fluid flush and it appears that the stiff brake pedal issue has vanished (after stalling the engine), but the brake pedal still won't return. Anyone have an idea on how I should go on about troubleshooting this? Could there be a possibility that there's still air in the lines or the bmc or booster is going? TIA!

Make sure your brake bleeding screw is on the top of the caliper

What's your brake bleeding order?

Brake bleeding screw's on the top side of the caliper on all four. When I bled the brakes, I bled from RR, RL, FR then FL (USDM S13). From what I've read recently, the proper procedure is RL, RR, FR then FL?

you want to start furthest away and work your way forward...so RR, RL, FR, FL in a USDM LHD car...your brake booster may be shot which would be a vacuum issue

The proper order is RL RR FR FL

I would also look into what Jedi said, I am replacing the brake booster on my S14 because they have weird application pressure after not using the brake for a bit..

Would RockAuto brake boosters be good enough as a replacement or should I try to find a used OEM booster?

Remanufactured ones are usually on the bottom of my list tbh.

S13 Brake boosters should be easy enough to find or contemplate having yours rebuilt.

agreed...maybe autozone...at least you have a warranty then...OEM is most likely long discontinued...

Thanks guys, I'll look into getting a new booster and I'll update you guys on how it goes

Just wanted to follow up on this if anyone has the same issue in the future, I changed the brake booster with a new unit from RockAuto and the brakes function just as they should.

Lessons learned:

If you intend to remove the booster, I highly suggest you remove the BMC first, since you'll run into issues removing the booster given the tight space (I highly suggest threading the clevis joint all the way in to make your life easier).

One thing to note, I have a Z32 master cylinder and ordered a non-ABS booster. The pushrod that came on the RA unit was too long (even when threaded all the way in), and I used the OEM pushrod pin. When the master was bolted right up to the booster, the master cylinder was slightly opened. I used some washers to resolve this issue, which is unideal (but good to know the booster was the issue). Might look into possibly getting a smaller pushrod.

Lining up the brake booster to the brake pedal bracket took me a while. Slightly undoing the brake pedal bracket helped line it up with the booster, although tightening the brake pedal bracket back in place was a pain since the nut on top that kept it in place was hard to reach.