Brake problem

So for most of this race season my brakes have been a little weird. The car stops fine and all. I have ABS disabled, but I'm only stopping at under 130 mph. That part is fine. I have a soft pedal issue, that has cost me several races and a ton of dough. It happens on the line when I brake torque it up against the converter. It jumps at around 2000 rpm. It used to ramp to around 27-2800 before the rear brakes would let loose. I even have a good line lock on the car.

Last week I bled the brakes for 3 days in a row. No chage in pedal firmness. Today I installed a set of Stoptech SS braided lines and I will gravity bleed it again tomorrow. The brake shoes and rotors all look fine to me, but I do have a fresh set of bendix pads at the ready.

Oh yeah, I forgot to say what caused this. I was getting an alignment at Mr. Norm's when I noticed a little brake fluid on the right rear caliper. A banjo bolt on the fitting was loose. Maybe I just have massive amounts of air that only power bleeding can get out.

at the beginning of the the season i bleed all new fluid in. using brembo evo 500+ fluid, stoptech braided lines, and titanium backing plates for the pads.

i had a soft pedal once and it was because i tried to track on old fluid. after the first lap my foot went to the floor going into the stop box. it was a little scary. ever since then i do a full fluid replace every spring and i also bleed some out before each track day to have fresh fluid in the system.

most normal brake fluids have very low "wet" boiling points. water from condensation gets in the lines and contaminates brake fluid fast. with a low wet boiling point you will get air in the lines when it boils causing all sorts of problems. i pick brake fluids by which one has a great "wet" boiling point or doesn't drop off as much when wet.

Thanks, Jon. System has all fresh fluid. See what happens after bleeding again with the new ss braided lines.

Tom you might as well upgrade your breaks to something like Baer and when this happens I have dibs on the brembos.
It is really the only next logical step

Just ran my 3rd big bottle of bf through it. The ss lines are on. They still feel soft. The pedal just sinks after I pump them up.

There might be an air bubble in the ABS system or something liek that, those are a bitch to get out, it might have sucked up through that loose fitting and all the way up there, OR taking a long shot, the mater or booster might be fucked up. Is the booster getting the correct vacuum?? With all the mods ya know man??

I had the exact same problem with mine. The pedal felt too soft. When I drove my Brothers Daytona, it felt like it should so I know mine wasnt how its supposed to feel. I never figured it out, I changed rotors, pads, flushed the brake fluid with new fluid. The only thing I didnt do was the SS lines but that was going to be my next step.

It would appear that there is an air pocket in the master. I would start there rather than in the lines at this point.

Moparcharger06 wrote:

There might be an air bubble in the ABS system or something liek that, those are a bitch to get out, it might have sucked up through that loose fitting and all the way up there, OR taking a long shot, the mater or booster might be fucked up. Is the booster getting the correct vacuum?? With all the mods ya know man??

This is all greek to me.

KevinDSClark wrote:

It would appear that there is an air pocket in the master. I would start there rather than in the lines at this point.

How do you get the air pocket out of the master?

im going to agree with everyone in saying its probably an air bubble.... Bleeding the master is a bitch, i believe you have to remove the lines from the master cylinder and pump the fluid through each port.. then move down the line to the abs controller, and then down to the calipers, removing the ends of the fittings and bleeding fluid through each line...at least this is process i've used in the past and has seemed to work for me.

Well I think I finally got it. I kept working that rear pass side that I found the loose fitting on. Got a pop and saw a bubble again today. Did the other rear quick. Started up and it feels much better now. The line lock is rock hard again. the regular brakes feel harder on the pedal, not rock hard but just gives a little and still feels firm with very little give. 2 in. or so and a feeling of pressure when it does give instead of that wimpy give I was getting.

Just get a fucking parachute!!!

Shawn1112 wrote:

Just get a fucking parachute!!!

I'd like to need one, lol.

On some scanners you can "engage" the ABS pump, if you can get a scanner that can do that, open one fitting at a time, and engage the pump, keep the master full and hope for the best to see a bubble pop out. That's the next step I'd have to say if ya can't get it man

Moparcharger06 wrote:

On some scanners you can "engage" the ABS pump, if you can get a scanner that can do that, open one fitting at a time, and engage the pump, keep the master full and hope for the best to see a bubble pop out. That's the next step I'd have to say if ya can't get it man

It's better, I'll keep bleeding that pass rear some more and see if I can't get some more air out. The pedal is much better, but could be firmer.

Must be fixed, I never jumped once at the line today. The kid is BACK! kickin' it. Brake torqued all day with NO issues.