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Hi there! I've been having a problem with my OEM Brembos during track days. This has happened on 100% of the track days I've been to.

FYI, I flushed and bled the system before this started, and use ATE Super Blue and Hawk HP+.

After a session or so, the pedal starts to get longer (happened faster at NHIS than at the Glen) and I start seeing fluid leaking from the bleeder valves. Unsettling, to say the least. There is never a LOT of leakage (basically undetectable from the master cylinder level, and even that is probably pad wear as well). In addition, I know that it continues to purge a bit after I stop, since at the height of the problem, I go to check tire pressures and torque lug nuts, and there is a little dribble of dried fluid sitting on the flat surface of the wheel (where it would drip if the car were stopped and you cracked a bleeder valve with no tubing).

I'm about 90% sure that the fluid is coming from the thread area of the bleeder screws, not through the channel. I say this because I'm pretty sure the rubber boot stays dry inside when this is going on. I also know that the fluid is not the leftover fluid in the bleeder screw from bleeding, because I wick that out with a paper towel after bleeding, as well as anything in the boot.

The bleeders are torqued to spec (9-11 ft-lb).

I've had people tell me they think the bleeder screw torque is too high, but I'm working out of the '03 manual. Hopefully it's not a typo and supposed to be in-lb. I've had people tell me I probably have dirt in the seat between the screw and caliper (unlikely, unless I managed to suck air AND dirt in on all 4 corners, since it happens everywhere).

Anyone else having this problem or have a solution? Thanks in advance.

uwaeve.
 

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Good question! I also have Brembos and track my track model.

I think you need to do some trial and error elimination. It could be a couple of different issues and it could just a cobination of a few. I agree with the others. I would point my finger at dirt and grime. I might also suggest pad threads on either the bleeder valve or the caliper. For example, if the bleeder was ever over-tightened, it could have skipped and tread and chewed it up.

So, I would suggest starting with the cheapest test and working from there. Since you have Ate fluid, I presume you are familiar with www.raceshopper.com. You can get "Speed Bleeders" there that will replace the existing bleeder valves you have. This will also enable one man bleeding in the future. I would just replace your existing valves with speed bleeders. When you do so, take out the old valves. Then, as the fluid seeps out of the caliper, use a very small wire brush with soft synthetic brissles to clean the hole. The seeping fluid should carry away any dirt. Then, install the new speed bleeders and bleed the system.

Doing this will not only bring a benefit (one man bleeding), but will also eliminate dirt and bad valves or valve threads as the culprit. If they still seep the next time you go to the track, then you know it is either the threading on the caliper body or it is seeping from another location. If it is the threading on the caliper body, I would NOT try to run a tap through the treads yourself. Instead, have a pro (machinist or otherwise) re-thread the holes of you.

Good luck.
 
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