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I was very lucky yesterday. I did a track day at Laguna Seca, and on the very last session, I got the checkered flag and just let the car coast down the hill to let the brakes cool off. When I got on the brakes gently, I had no pedal. Even with pumping it up, I had barely any pedal at all. If I had not gotten the checker exactly then, I would have crashed at the end of the braking zone. I thought I had just overheated the brakes, though I was surprised because I'd had minimal brake fade throughout the day, and none in the previous corner before the S/F line. Even on this cool down lap with me pumping up the brakes, I had almost no pedal at all.
Got back to the pits and saw a puddle of brake fluid at the driver's side rear wheel. When I inspected the caliper, the bleeder screw had turned itself out and was only a few turns from being out completely. On hot days at tracks with heavy braking zones, I've overheated the brakes and had fluid boil past the bleeder, but I've never actually seen a bleeder screw come out like this. Usually I bleed my own brakes, but just prior to the event I had my mechanic (who's excellent) bleed the brakes while I pumped the pedal. So, I don't think it was a case of him not tightening the bleeder screw enough.
Has anyone had this happen?It's a first for me after 3 years of driving the !@#$!@ out of my car at multiple tracks. Any solutions?
Bleeder screws just don't back out. Someone didn't torque it properly or the caliper housing threads are stripped. If you a tracking your car it should be prepped for every event.
There is no way that fluid can get by the bleeder screw unless it is loose, stripped or defective. What can happen is when you bleed the brakes and finalize tightening the bleeder tight, a little fluid can remain in the top of the bleeder when you remove the hose. You don't notice it there but once out on the track and things get hot it will "spill" out and look like you have a leaky bleeder screw.
Sounds like your car held out as long as she could to keep you safe........funny how those things happen
Glad to hear this had a happy ending! I would also agree with the previous comments on the bleeder screw. They just leak or back for no reason. Personally I would replace all of them and flush/replace your brake fluid and better yet get a AP Racing front brake kit.
I could swear that I've heard other people on this forum complaining of fluid leaking past the bleeder. But yeah I guess it doesn't make sense if you think about it.
I've had fluid leaks like this before, but never a loose bleeder.
Note that I replace the stock rear calipers once a year on my car. (Fronts are Willwood). I bleed the brakes and check them before ever event. I'm thinking that maybe there was dirt or something in the bleeder when it was torqued? Again, the guy who torqued them is a very competent mechanic.
Just talked to my mechanic.
He thinks that the screw/caliper was probably stripped from over torquing in the past, and that with vibration the screw worked its way loose.
He also thinks that the previous times I'd seen a brake fluid leak (nothing like this; just some on the inside of the wheel) was probably from fluid getting past worn piston seals.
...
Note that I replace the stock rear calipers once a year on my car. (Fronts are Willwood).
Why not look into getting matching Wilwoods for the rear and see what replacement pads cost. I just upgraded my fronts to AP Racing and the same brake pads for them is a $120 cheaper a set.
I'd suggest you replace the entire bleeder assembly; the base fitting as well as the small nipple. Being 1/4-28 thread high torque is not necessary to close it however repeated over tightening of them could cause some issues. The 2pc bleed fitting has the benefit of not damaging your caliper in this situation; meaning the threads and seat in the alum body remain undamaged regardless of how much bleeding is done over the life of the caliper.
I've also seen issues where owners/mechanics don't even understand how this 2pc works and attempt to bleed the brass fitting. (despite the notes in the instructions....) and that leads to much frustration and possible leak around the nipple if it's not tight simply from mass assembly of the parts prior to caliper assembly.
You'll need to identify the type: NPT (pipe thread with sealant) or M10 (a tapered seat) for your particular caliper.
The small black fittings (your damaged part) is not available without the entire unit.
I'd suggest you replace the entire bleeder assembly; the base fitting as well as the small nipple. Being 1/4-28 thread high torque is not necessary to close it however repeated over tightening of them could cause some issues. The 2pc bleed fitting has the benefit of not damaging your caliper in this situation; meaning the threads and seat in the alum body remain undamaged regardless of how much bleeding is done over the life of the caliper.
I've also seen issues where owners/mechanics don't even understand how this 2pc works and attempt to bleed the brass fitting. (despite the notes in the instructions....) and that leads to much frustration and possible leak around the nipple if it's not tight simply from mass assembly of the parts prior to caliper assembly.
You'll need to identify the type: NPT (pipe thread with sealant) or M10 (a tapered seat) for your particular caliper.
The small black fittings (your damaged part) is not available without the entire unit.
.
These work great at saving the bleeder screw threads in a caliper. All of the wear and tear takes place in the brass fitting and not in the caliper. It takes two wrenches to loosen/tighten these fittings. One to go over the brass fitting to make sure it doesn't move and one to turn the smaller bleeder inside the brass fitting.
06-29-2018, 11:40 AM
C5 brake failure at track
