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S197 3V Rear brake piston frozen

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55
47
Exp. Type
HPDE
Exp. Level
Under 3 Years
South Carolina
OEM GT rear calipers, Steeda braided stainless lines. This weekend replaced wheel studs and brake pads (from OPTim, of course). Left side no problem--piston retracted easily with tool. Right side piston would not move. Reviewed this thread: https://trackmustangsonline.com/threads/rear-piston-cant-get-it-reset-for-new-pads.9647/ (.) Banjo bolts same both sides. Removed caliper and blew out piston. This:
20240303_135158.jpg

Already ordered new (remanufactured) caliper. With my record, something I did caused this. Any ideas, so I don't do it again? Thanks.
 
1,160
1,159
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
Already ordered new (remanufactured) caliper. With my record, something I did caused this. Any ideas, so I don't do it again? Thanks.
I would try to find a new oem caliper. Remans do not hold up to track use. I went through a set every weekend or two before having a Ford dealer order me a set of new oem. No problems since then.
 
334
353
Any ideas, so I don't do it again? Thanks.
Do you mean the piston wouldn't move as in it wouldn't turn, or it was turning but wouldn't engage back into the caliper? I've had the second problem when I let the pads wear too far down and the piston is extended far out of the caliper. Lots of pressure while turning has gotten it to eventually catch and work properly again.
 
179
67
ny
That piston is junk. I have heard of reman, s failing with track use. New oem not sure they are still available. If you set that needs rebuilding send them to Apple hydraulics on long Island ny . Call speak w Lars tell him usage he knows his stuff.
as for cause looks like piston got cocked .check bore see if scored?
 
55
47
Exp. Type
HPDE
Exp. Level
Under 3 Years
South Carolina
Do you mean the piston wouldn't move as in it wouldn't turn, or it was turning but wouldn't engage back into the caliper? I've had the second problem when I let the pads wear too far down and the piston is extended far out of the caliper. Lots of pressure while turning has gotten it to eventually catch and work properly again.
Piston would not turn in either direction (in/out), so I could not install new pads. Old pads had only ~4000 street miles, so piston was only extended about 5mm.That was still 2mmtoo far to fit the new pads.
 
55
47
Exp. Type
HPDE
Exp. Level
Under 3 Years
South Carolina
That piston is junk. I have heard of reman, s failing with track use. New oem not sure they are still available. If you set that needs rebuilding send them to Apple hydraulics on long Island ny . Call speak w Lars tell him usage he knows his stuff.
as for cause looks like piston got cocked .check bore see if scored?
I figured as much--that's why I ordered the reman caliper. When/if it fails, I will give Lars a call. I didn't see scoring in the bore, but there must have been something. I'm starting to wonder if I used a longer banjo bolt in the right caliper, as discussed in the thread linked above. Thanks!
 
6,394
8,275
I figured as much--that's why I ordered the reman caliper. When/if it fails, I will give Lars a call. I didn't see scoring in the bore, but there must have been something. I'm starting to wonder if I used a longer banjo bolt in the right caliper, as discussed in the thread linked above. Thanks!
I think that is exactly what happened, the banjo bolt went in too far, maybe the new stainless banjo was narrower than the stock one. With regards to the piston, if you file the burrs off, and leave the indentation, the piston will work fine, if that piston ever gets to where that burr is anywhere close to the seal, you are already into a wall. I had to rebuild some calipers from a 68 Dodge dart that had Girling ( I think, it's been awhile) and no replacements were available, we had to use what we had. So if you can find an OEM rebuild kit vs some aftermarket stuff, I would have no issue re using that piston as long as it was still round and not cracked.
 

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