Wilwood brake fluid leak...this can't be normal.

[Randy's]

I purchased the Wilwood brake upgrade for my complete kit and purchased an additional master cylinder so that I have separate Wilwood master cylinders for the front and back. I installed everything a few months back and had a few flairs that leaked. I took care of those, bled the brakes and all looked good. I am not to go kart stage yet. I am still sitting on jack stands so I have not "used' the brakes. Two weekends ago, while mounting my tires, I noticed brake fluid on the bottom of the rear calipers. It was not enough fluid to even cause a drip. There is no fluid on the floor, just on the bottom of the calipers and only the rear calipers. I've checked all my fittings/connections and have no fluid leaks there. I thought perhaps it was just left over fluid from the former leaking flairs so I wiped them off making sure both were clean and dry. I pumped the brakes and noticed the pedal was no longer as firm as it was earlier. After a few pumps, they firmed back up. I felt the bottom of the rear calipers and they were still dry so I'm thinking I'm good. Since then, about every other day, I have felt the bottom of the rear calipers and the fluid is back. I clean it but it keeps coming back. However, it is never enough to make it drip. I pump the pedal and it is soft but firms back up. The fluid level in the master cylinder does not seem to be dropping. This can't be normal or else it would be happening with the front calipers, right? Could I have bad calipers? If it were only one leaking I might conclude that it is defective but it seems unlikely that I would have received two bad rear calipers. Any one else experience this? I don't want to take any chances with something as important as the brakes. Any suggestions on what to do would be most appreciated.

[michael everson]

I would push the brake pedal on and hold it with a 2x4 or similar and then climb under there and watch it. With pressure held on it, it should drip much faster. More than likely one of the fittings is leaking. Did you use pipe dope or tape on the NPT fitting that went into the caliper?
Mike

[Randy's]

Mike, I used tape. Should I have used something else, or nothing at all? I should also note that the front calipers have banjo bolts, the rear ones do not.

[kobra01]

I had the same problem. Mine was leaking from the fitting that screws into the caliper. I called Wilwood and they told me to put regular white teflon tape on them. No more leaks.

[edwardb]

I've avoided tape based on many comments on this and the other forum about not using Teflon tape for brakes. On my builds, I've always used Permatex sealant. Not had any trouble with leaks on those fittings and I've used Wilwood brakes several times. BTW, your brake pedal going soft, even if it can be pumped up, is a big red flag. That has to be fixed and never repeat. It's always a sign of something wrong.

[Boydster]

Agree with Ed Paul. Brake pedal that goes soft and needs to be pumped is a sign. Maybe just needs more bleeding.

[CFranks]

I’m fighting a similar issue (I have standard GT brakes though). Every few days some fluid would form on bottom of rear calipers. I tried to “fix” them and ended up breaking the right caliper. Bought 2 new calipers (thankfully they’re cheap!) and same problem. I believe I’ve isolated it to the banjo bolt fitting slowly leaking and then tracking down to the bottom of the caliper.

[Railroad]

If you have the Wilwood calipers with multiple bleed ports, make sure they are all tightened. It seems some of mine took a bit of tightening from the delivered condition.