Rear Caliper Problem

[jmimac351]

For the past few events I've had trouble chasing down a problem with a leaking right rear caliper. At first we thought maybe it was a loose brake line fitting. We re-tightened and bled them out. No leak was evident during that process. After a few sessions the caliper was covered in brake fluid again. I thought maybe the issue was a worn copper gasket. The piston seals / boots were bone dry.

Since that event I went through and bled all of the brakes. Again, once I wiped the right rear clean and bled it out it stayed dry in the garage. I spent five minutes jumping on the pedal and not a hint of moisture. "Ok, must be fixed"

Yesterday at PBIR the leak was back (heat related?). We pulled the caliper, and separated the halves. There are torx fasteners which we checked for tightness - they were. We saw two o-rings which we thought might be the culprit - replaced them. Went back out and the "leak" might have been a little better but by the second session the wheel was smoking when I came back in due to fluid on the caliper.

When you separate the halves, there is a flared "fitting" that the o-ring surrounds. Is that a replacement item? I guess there could be some sort of minute crack in the caliper but I wouldn't expect that.

Worst case, does anyone know a good source for a replacement? I'm checking with Brandon at PAD but I am dreading how much these things may cost.

[panozracing]

Originally Posted by jmimac351

Worst case, does anyone know a good source for a replacement? I'm checking with Brandon at PAD but I am dreading how much these things may cost.

I have a brand new one in the box if you end up going that route. I thought I needed it but the leak ended up being the seals so we just kept it. I dont remember what PAD charged me but let me know what the current cost is and I will be a bunch less.

[jmimac351]

Thanks. I'll let you know.

[eric1h]

probably a bad seal as panoz racer said above. Call PAD And get a rebuild kit or there is another thread with the seal PN#'s and links to find them.

[jmimac351]

I have a rear seal kit from PAD but the boots / pistons are absolutely bone dry so I'm not sure how that could be it. The body of the caliper is wet when under stress. Strange. I think I'm just going to punt and buy another. This, talent, and tires are on only things keeping me from beating Pomroy.

[eric1h]

have you replaced the bleeder valve? I've seen those go bad and leak/seep fluid under pressure? you don't have speed bleeders installed do you?

[jmimac351]

Nope. But like I said you can bleed it out and it stays bone dry after repeatedly standing on the brakes until you're tired. Take it to the track and it leaks. Maybe it gets scared and wets itself. That's not so plausible because I don't go very fast.

[eric1h]

Originally Posted by jmimac351

Nope. But like I said you can bleed it out and it stays bone dry after repeatedly standing on the brakes until you're tired. Take it to the track and it leaks. Maybe it gets scared and wets itself. That's not so plausible because I don't go very fast.

Are you sure its not the rear axle seal leaking?

Either the heat from the brakes is making the bleeder screw leak, or the rear axle seals are leaking(which they are VERY prone to do.

[jmimac351]

---> This Guy!

UPDATE: after prolonging as long as possible what should have been painfully obvious from the outset, I went ahead and replaced the copper washer on the caliper line fitting that I was "sure...positive...no way is that leaking because that sucker is TIGHT". Went to Sebring today and that resolved the issue. (It's nice to be confident in the brakes again.) In the process of chasing this leak on 3 occasions, always fun at the track, we split the caliper in half and replaced the two small o-rings inside (not the source of the problem). I was just tightening the caliper fitting and the caliper would bleed out with no leaks each time. Then at the track it would leak (heat, I guess) and it was difficult to tell where it was coming from.

Bottom line, no matter how tight and "sure" you think that fitting is and is unlikely to leak, change the copper washer if you turn that fitting. Oh, I guess "that's" why they use a copper washer.

ps: To remove the rear caliper, loosen the two nuts that point "forward" - not the caliper bracket. The caliper will slide right off the studs it's mounted to. Easy.

[Gatorac]

Told you that's where it was coming from...

[jmimac351]

Originally Posted by Gatorac

Told you that's where it was coming from...

Yeah, after I fixed it. I hold you personally responsible for this fiasco.

[Panoz26]

L O L

[cvgt3]

good to meet you at sebring this weekend... you mentioned someone had used replacement calipers who? glad you had fun sorry I didn't get time to stop by chip

[panozracing]

Originally Posted by cvgt3

good to meet you at sebring this weekend... you mentioned someone had used replacement calipers who? glad you had fun sorry I didn't get time to stop by chip

Wellllll, after reading the cure to the caliper leak I was happy and bummed. Happy you fixed it and sad I was still stuck with a brand new rear caliper sitting in the box. Then I read the post by cvgt3 and there is a dim light of hope? I am the guy with a "NEW" (well I installed it and then realized that it wasnt the problem and took it off but because I ran fluid thru it PAD wouldnt take it back....it was never driven/used with this caliper).

PM me if you need the caliper.

[jmimac351]

Hey Chip, good to meet you as well. Thanks again for your advice. Pomroy is heading to Homestead and I am considering going as well now. I've never been so maybe one of you guys can show me around. Gary Jones is the guy that has quite a few spares. Gary Jones Motorsports in Augusta. He's sold a number of GTRAs. 706.592.0060

Brian, fyi I sent you an email about the caliper previously via this site. This site seems a little glitchy so it probably didn't work.