I have a soft brake pedal. I've changed the brake pads put in a new brake booster and new master cylinder. Master cylinder was bench bleed. The lines have been bleed several times, no air. I haven't changed the proportional valve, no signs of leaking. There are no leaks at the wheel cylinders.

Thinking I may have a bad master cylinder, looking for suggestions..

 

Sometimes bleeding can be tricky, so don't rule that out.

 

I had (have) the same problem on my 93 Delsol Si. Replaced MC w/ a larger 7/8 MC, pads, rotors, Bled it for days, everything seems fine. Soft pedal is still there, I just got used to it.

I personally blame it on old rubber brakelines expanding under pressure because its not as bad in the winter.

 

How's the check valve? If its leaking the pedal will start sinking, tho same with bad booster iirc.

 

Did you use the proper bleed sequence?





eH.

 

Yes

 

Going to rebleed the brakes again. If that doesn't work will take MC back under warranty and go from there.