barshroom

1995 S14. First had Z32 calipers front, stock master, stock skinny booster, stock rear brakes. pedal feel was soft but I wasn't a big fan. Upgraded master to a 17/16 unit and pedal is too firm, wasn't a big fan of that either. Just wrapped up converting the rears to Z32 with all the parking brake goodness. My question before I work on the car again tomorrow: Does adding the rears into the brake equation fix the stiff pedal issue? I ask because I have a dual diaphragm Z32 booster laying around but I'm having my doubts on if it'll fit or not.

It's not so much the pedal being stiff thats troubling me but the fact that I'm getting no response from the car when braking.

NukeKS14

I'd look into a 1" bmc. I'm on a z32 front / stock rear setup with a 15/16 bmc and I'll be looking into the 1" z32tt with a z32 booster when I convert my rears later this summer.

https://importnut.net/the-definitive...cylinder-swap/

Some light reading for thought.


Short answer no, your stiff pedal is due to fluid dynamics. Contrary to what you think, the LARGER you go on bmc diameter the stiffer the pedal will be. Pressure is force/area. Larger area, same force = less pressure. You can fix your stiff pedal issue by going down a size in BMC piston diameter or installing a larger booster.

I would check for air in the lines but what you're describing is a common 17/16 complaint when using the stock s14 booster.

e1_griego

I like the 15/16" master the best for full f/r z32 brakes. I think the 17/16" only works for big front brakes -- e.g. wilwoods, etc.

barshroom

Ive read that importnut link inside out prior to doing anything to the car. I agree that the larger diameter master will reduce clamping force and move more fluid under less pressure... giving a stiff pedal, but, what im looking for is if anyone switched over from stock s chassis rears to z32 and noticed a difference. I love the stiff pedal feel but the lack of travel is what is concerning me.

barshroom

I bit the bullet and unbolted my master and booster from the car. Putting in the z32 booster in tomorrow and adjusting it to around the same settings as the old booster. I have thought of doing 6 pistons up front later on if the current setup isn't how I want it. No point in wasting a new master cylinder

barshroom

Update:
By far the most fucked thing i've had to do. From cutting the studs on the booster down to wrangling it in the firewall to lining it up on the pedal. Bled the brakes and pedal feel is wild. Didn't adjust the rod far in enough and now I have cruise control brakes. Will have fun with that tomorrow. This is definitely the way this brake swap is meant to be done though. MC, Booster, Front and Rear calipers.

barshroom

Forgot to update this thread... Having too much fun with the car. FUCK any other half assed brake swap. The booster is a must if you change master cylinder. Night and day difference. Pedal kept it's stiffness maybe softer in the slightest but pedal feel and bite actually exist now.