90 integra BRAKE problems
 

I am going to start off by saying that I have read posts on this site and others and have not found a definite answer.

MY PROBLEM:

Here is my issues with the acura racecar - ABS removed and non-ABS front lines and Prop valve installed along with type R front calipers and stainless lines all around

hard pedal when pumping with the car turned off but as soon as the car is on - the pedal is super squishy like the master is bypassing or air in the lines?

PARTS INSTALLED :

New pads
2 new master cylinders have been try and bench bled before install
new stainless lines
new front calipers

The only other thing that checks out with tests that has not been changed is the booster ? My though on a bad booster is that if its bad the pedal would be hard not soft.

a buddy and I also bled about 2-3 bottles worth of fluid through the thing with no results. we thought it was air in the line somewhere that just wont come out.

Please only post if you have had this same issue and know what was done to fix it.

THANX
Chris Doodson

I have to ask, how did you do the brake bleeding? Also, if you pump the brakes and hold with the car off, does the pedel stay where it is or slowly lower?

Brakes
 

bench bled the master, and have bled the brakes both by gravity and PUMP-PUMP-PUMP- crack-close method.
RR-LF-LR-RF
and the pedal does stay and does not sink over time. We also did the booster tests as per HONDA/ACURA service manual and the booster checked out fine.
I am thinking there are 3 posible causes.

Another bad master - not likley but possible
Air in the system - bubble sitting somewhere like Prop-valve
Fitting is leaking air into the system but no fluid coming out?

if bench bleeding doesn't work, i'd look at the booster

have you ever heard of a booster making the brakes soft? I thought when it goes bad the pedal gets hard?

Depends on what goes wrong with the booster. If it's a leak, then yes, the pedal goes hard, and you'll have a hell of a time stopping cause you have no boost. And the engine will likely idle bad because of the vacuum leak.

But it does remind me a case i had back in the mid 90's. Customer drove his 91 prelude into a ditch and car was partially submerged in water. I replaced the trans and repaired some other electrical issues. But the brake pedal was very soft. I replaced the master cylinder (bench bled it) bled at the wheels but still had a soft mushy pedal. I ended up removing the booster. When i had it out and tipped it over, about half liter of water spilled out. Replaced the booster and it was good.
I think the customer still has that car, i'm sure i seen him at our dealership with the car around a month ago.
I also remember him saying to the service adviser, when he drove into the ditch, that caused him to spilled his rum and coke