We have been enjoying our Mustang track project this year. But, the seals keep blowing out of the rear calipers. They are remanufactured ones. Is there anything I might be doing during installation that may be contributing to this?
Maybe they aren't capable of sustained heat from lapping? The brake system is stock, with the exception of stainless steel brake lines. And we are running Hawk HP+ pads. For what it's worth, the base cars and the GTs share the same rear brakes.
Any signs of overheating?
Master cylinder adjustment? <<<<<<<
Caliper mounting issues?
One side or both?
Axle end play?
Reman calipers can be pretty crappy sometimes. Have you taken apart one of the blown ones to see how the seal failed? Any pictures? Is it a "I noticed some fluid leaking from the rear caliper" failure or a "I just lost braking power" failure?
My first thought, if the failure seems to be heat-related, is to try one of those thermal barrier plates between the pad and the piston. If the caliper pistons are aluminum, and somebody makes a steel replacement, that's another way to reduce heat in the fluid. Slapping a shim between the pad and piston is a lot easier, though :)
Are other people having this issue?
If it's heat related you have the options of the aforementioned shims or ducting some air to the calipers (it is a fairly easy fabrication job to get some ducting to the caliper/disc).
If the brakes are getting hot enough to fry the seals I would expect that you would have some level of brake fade (maybe not)
My inclination would be to put the best quality calipers available on the car and then go from there.
I'd be tempted to go with Ford calipers next time you need to pull them. I've never had good luck with reman'd units
How far are you wearing the pads down? Thinner pads run hotter. Or are the calipers failing at any pad thickness?
I seem to recall a GRM advertiser that was hawking titanium brake pad shims. Titanium is very poor at transferring heat, so the shims would keep pad heat out of the calipers. Might be worth looking into, even if you ended up buying some thin Ti sheet stock and making your own.
bentwrench said:Any signs of overheating?
Master cylinder adjustment? <<<<<<<
Caliper mounting issues?
One side or both?
Axle end play?
There doesn't seem to be any sign of overheating. I can't see any issue with the caliper mounts.
It does seem to happen more with the driver's rear (twice so far). I don't know anything about a master cylinder adjustment, or measuring axle end play (my first stick axle). I'll do some research on those leads. Thanks!
Tom1200 said:Are other people having this issue?
If it's heat related you have the options of the aforementioned shims or ducting some air to the calipers (it is a fairly easy fabrication job to get some ducting to the caliper/disc).
If the brakes are getting hot enough to fry the seals I would expect that you would have some level of brake fade (maybe not)
My inclination would be to put the best quality calipers available on the car and then go from there.
We aren't getting any fade from the brakes (running RBF600). But I wonder if the traction control uses the rear brakes somehow -- I always turn it off, but I'm not sure my wife does. That's a thought . . .
Pete. (l33t FS) said:How far are you wearing the pads down? Thinner pads run hotter. Or are the calipers failing at any pad thickness?
I seem to recall a GRM advertiser that was hawking titanium brake pad shims. Titanium is very poor at transferring heat, so the shims would keep pad heat out of the calipers. Might be worth looking into, even if you ended up buying some thin Ti sheet stock and making your own.
It's happened with new pads, and now, with what remains of the new pads (I haven't pulled them to measure yet). The car is home, and I'm at the cottage.
How tight are the pads in the bracket? Or excessive piston and bore clearance?
Im just thinking out loud and wondering if it might be excessive play applying a side load to the caliper piston and seal. That could cause wear on a specific area or possibly increase clearance enough on one side to initiate the seal failure as clearances change with temp.
Excessive clearance between the piston and caliper on a reman caliper could also cause that, but it seems to be something related to the car or design and not a bad caliper.
It would be good to remove the piston and inspect for damage to see if you can see if it's specific location that shows wear or scoring.
ZOO (Forum Supporter) said:We aren't getting any fade from the brakes (running RBF600). But I wonder if the traction control uses the rear brakes somehow -- I always turn it off, but I'm not sure my wife does. That's a thought . . .
That's a good thought. My C5 will cook rear pads on track unless the traction control is turned off.
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