Inconsistent Pedal

[Ginger_Extract]

Hey 1Addicts, hoping you could help me do some trouble shooting. A while back, I boiled the brake fluid quite badly at the track, to the point where the pedal did nothing and I had to engine brake off the track, and the brake light came on the dash. I have bled the brakes a handful of times since, but the pedal is still very inconsistent. Sometimes it feels great, then the very next time I go to use the pedal, even seconds later, it feels awful, going to the floor with minimal brake force. The issue persists with different pads, rotors, etc.

I have tested the master, it is holding. None of my brake lines seem to be leaking/the system doesn't show any leaks anywhere. Each bleed of the calipers is showing minimal bubbling, and a firm enough pedal when bleeding.

Any ideas on how to proceed? I have been living with the bad pedal for a while now, it is driving me nuts. I have gotten into the habit of pumping the brakes before diving into the pedal stroke, just so I would have brake force. That to me, indicates air in the system, but as previously stated, bleeding the brakes is showing minimal issues with the fluid.

[Dackelone]

Check the brake piston seals for leakage. I bet you got the brakes so hot that the brake caliper piston's are leaking. Did you ever change your brake pads after your HPDE ?

[ShocknAwe]

What about a brake fluid change at this point?

[Ginger_Extract]

Originally Posted by Dackelone

Check the brake piston seals for leakage. I bet you got the brakes so hot that the brake caliper piston's are leaking. Did you ever change your brake pads after your HPDE ?

Pistons are fine, no leaking. The rubber boots surrounding the pistons have minor tears but thats no big deal. Changed pads several times experimenting with different compounds. Pad wear is good and even, across the different pads that I have used. Same for rotors.
I was thinking perhaps that air bubbles have lodged themselves in the ABS actuator, since the air bubbles rise, and the actuator is the highest point of the system. However, that's just a guess. I don't tend to ride the ABS much at the track out of habit, so I am not sure how much that could factor in.

[Pig Farmer]

I experienced a similar condition when swapping out my calipers to a BBK. I'm pretty sure I ran the resivour dry and had a massive amount of air in the lines. Using a pressure bleeder was worthless. The two person process (with the engine running) helped a lot. A couple weeks later I installed my COBB. During the installation, you can hear just about every electric pump in the car cycle a few times. I can't confirm whether the the the ABS actuator is activated by the COBB, but after the installation my brake pedal pressure was better than new.

Also, if you check the internet, you with find some articles where a guy with an e46 figured out how to pull the ABS relay in the fuse box and jump the contact points to activate the ABS. I'm sure this wouldn't be difficult once you figure out which contact points related to the relay's on/off circuit.

[A_Squared]

Originally Posted by ShocknAwe

What about a brake fluid change at this point?

I'm thinking the same. Mentioned he changed everything but the actual fluid completely. Why don't you try that, flush the fluid completely and re-bleed the brakes

[Ginger_Extract]

I have bled several times since, including again last night! Was able to get some bubbles out, but pedal still feels lackluster. Are the masters/reservoirs really noisy on these cars? I noticed yesterday when I was bleeding, two man style that the master/revervoir was making a suction noise when the pedal was being pushed down. My friend said it sounded normal, but I'm paranoid. I don't recall other cars making noise from the master whwhen bleeding?

[Pig Farmer]

Not trying to freak you out, but I don't recall any noise from the MC. That being said, the car was in the garage with the engine running so I couldn't hear much of anything.