Sticking Rear Caliper

[JDos1]

My rear left caliper is sticking ever so slightly and I'm about out of ideas as to what to do. Originally I noticed the left wheel getting hot and the temp of the rotor was much higher than the right side. Pulled the caliper, noticed a seized slide. Replaced the caliper and bracket. Still getting hot. Investigated more and noticed the park brake bracket wasn't returning fully due to a weak spring on the new caliper. Swapped the return spring out with the OEM spring and slightly adjusted the cable. Now the parkbrake fully returns but the left side is still getting hotter. Figured maybe the brake line was internally damaged and holding pressure. Replaced the lines with braided stainless lines which seemed to help slightly but now the left side is still staying 50-75* hotter than the right whereas my Brembos are only 5-7* apart in temps. Any further ideas as to what to check next?

 

[noldevin]

Just had an eye twitch lol.
I've been fighting rear brake problems for what feels like forever. I had a sticking issue like you, then was unable to compress the piston back in all the way when removing the calipers/pads.
Finally discovered it was my aftermarket stainless lines, the banjo bolt was just a hair too long and interfering. Swapped back to stock lines and that issue is gone.

Now I just have incessant squeaking, which I am guessing is probably a pad or rotor defect caused by the heat. At least they compress and don't stick anymore.


TLDR - if you have aftermarket lines, try the stock ones.
Also make sure the slots in the backs of your pads are lining up with the notches on the piston (it also needs to be rotated when compressing, and the notches should be lined up with the pad). Make sure the rubber dust boot is still in good shape, if it's messed up some debris could have gotten in and damaged the piston or got stuck. In that case you'll probably need to replace the caliper.

 

[JDos1]

I just replaced the caliper a week ago, like I mentioned, still having holding issues. Also replaced the stock lines with the braideds, as mentioned, this past saturday which seemed to alleviate some of the issue but it's still there. I reused OEM banjo bolts.

I'm 90% sure the notches were lined up but thought to recheck them this weekend along with cleaning the ABS wheel and pickup.

 

[JDos1]

And you pads are likely glazed over from the heat, remove the pads and lightly sand the surface and the squealing issue should be alleviated.

 

[noldevin]

And you pads are likely glazed over from the heat, remove the pads and lightly sand the surface and the squealing issue should be alleviated.

What grit?

 

[JDos1]

I would go no coarser than 320.

 

[JDos1]

Already ensured the slots were aligned with the rivet on the pads. I did noticed that the left axle has a TON of side to side/in & out play (pull in/push out on the hub). I wonder if the axle is trying to pull outwards as I'm driving putting pressure on the outer pad causing it to get hot? I did noticed the outer pad had less material than the inner. I'm going to swap out with the differential I purchased before Christmas (which has significantly less slop) next weekend. If that doesn't fix it I guess I'm going to have to take it to the dealership. Any ideas?