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Rear Brake Caliper stuck this morning (AGAIN!)

Duane Black

TMO Race
355
186
Durham, NC
Greetings citizens of TMO;

I've had a saga with rear brakes that just won't quit. The left rear caliper appears to have gotten stuck this morning at work... pulled into my parking spot and was overwhelmed a bit by the alluring odor!

So this started several months back. I swapped brakes to go to Roebling Road in January, and the brakes stuck to the point that it was dragging the car down BADLY. Like, you couldn't accelerate BAD. Then suddenly, they freed up after a mile. IT was also both brakes that particular occasion.

Fast forward a couple of months. The LR sticks on the way home from work, and it hasn't been bothered in a few weeks. With two incidents in close succession, I replace calipers.

Then I go through the bit where I had calipers not stop leaking. I replaced both rear calipers with new Motorcraft parts ordered through Tasca Ford just a few weeks back.

I swapped my brakes over to street after my Charlotte adventures Sunday. I also had a crack in a left rear rotor (not uncommon honestly - need to upgrade to those bigger ones you guys tell me about) and I move on with life.

I get to work this morning... the left rear brake was hot after getting to work, but the car never seemed to drag. It was hot enough that the cue was a smell when I got out of the car that overwhelmed again. I had the brake cylinder open when I pushed the piston back in. I did notice these new motorcraft cylinders seemed to be stiffer to turn back in than the parts store rebuild but I thought that could be better quality seals. They weren't overwhelmingly difficult, they were just more difficult than my parts store ones.

I'm thinking this is connected to changing pads somehow or another. But... it's a game that is just getting old.

I did not bleed the brakes - figured I'd wait until I change race brakes back in. The system was never opened beyond a master cylinder cap.
 
Last edited:

Duane Black

TMO Race
355
186
Durham, NC
What's a good way to check the caliper bracket to make sure it's straight? It's new with the calipers, I know that doesnt' always mean it's straight. It also didn't do this game until I changed pads - I'm thinking there is a connection.
 

Spencer Terry

TMO Advanced
158
84
Charlotte, NC
I agree, I would throw the stock lines back on it and see if that helps. I have had quite a few issues with rear brake lines and have gone back to stock at this point.
 

JAJ

TMO Addict
766
711
In the V6L
I agree, I would throw the stock lines back on it and see if that helps. I have had quite a few issues with rear brake lines and have gone back to stock at this point.
The 2013/14 GT500 brake hoses and the Boss 302 brake hoses were made from a low-expansion rubber hose that is very close to the performance of a stainless line. I had stainless lines (with shorter banjo bolts) on my 2011 Brembo GT, but I had no inclination to change the hoses on my 2014 GT500. Ditto my GT350, which has amazing brake presence and feel. Those "high performance" rubber lines are excellent and because they're OEM, it all works properly.
 

Coz

TMO Addict
867
649
Philly Metro Area
HPDE
3-5 Years
I think they share the design with Russell, with new pads the banjo bolt may be too long and it binds the piston.
I do not believe the J&M and Russell lines are the same. The J&M lines have the square fittings at the ends while the Russells have the round fittings.

If I recall when I got the J&M lines about 3 years ago they did not come with the crush washers or banjo bolts and I bought new OEM washers and bolts.

You do have crush washers on either side of the brake line banjo bolt fitting, correct?
 

Drlee50

TMO Race
327
155
US
The most likely problem is the caliper itself. Over time, the piston and it's adjacent wall develop rust and corrosion etc. Dirt gets in there etc. The piston then gets shoved back in, to max travel open, you install pads and pump brakes, pushing piston back out . the piston then gets all that rust and debris wedged in there and limits its free travel. Now it's hanging up and you are experiencing the symptoms. Replace the caliper. They are cheap

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Drlee50

TMO Race
327
155
US
your original problem was most likely the caliper itself. Over time, the piston and it's adjacent wall develop rust and corrosion etc. Dirt gets in there etc. The piston then gets shoved back in, to max travel open, you install pads and pump brakes, pushing piston back out . the piston then gets all that rust and debris wedged in there and limits its free travel. Now it's hanging up and you are experiencing the symptoms. The replacement caliper may have been a remanufactured unit and the piston still sucks in it's travel. Does it move in and out easy by hand? Or do you need a c clamp?


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Sent from my LG-H932 using Tapatalk
 

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