Hiya, a bit new to this forum, so apologies for stepping on anybody's toes.
I have recently (ie. the last fortnight) had cause to look at binding rear calipers, initially on the nearside, and after being quoted ridiculous prices for replacement (pads and shoes) I got down and dirty.
Rear pads were in need of replacement (approx 45k) but the shoes (inside the drum, for the handbrake) were like new.
I replaced the pads keeping my fingers crossed that this would solve the problem. They were a little too snug fitting into the calliper guides to be honest, but not having worked on this before (and it being 0 degrees, on my hands and knees) I didn't pay too much attention to this as the wheels did turn after refitting and hoped that they would 'bed-in'.
On my second attempt under the car (now a balmy 1 degree, but the hubs were hot enough), the offside wheel now seemed to be attracting more heat than the nearside. Both callipers could be moved (grunt) but I noticed that the pads stayed in contact with the disk, and were reluctant to move along the guides. The guides are lined with a different steel (stainless?) but the new pads just seemed to be too big (top to bottom mainly) to fit sweetly in the gap. My first thought was that the lacquered finish on the pads seemed to be too irregular and interfered with the fit but, remembering the reason I was here in the first place, dug the old pads back out of the bin to compare. Very little difference. Ok, so the stainless shims were in need of a thorough scrubbing but even so the fit was tight.
I wondered if crud was building up underneath the shims and played about trying to lift them and get a good look. They are obviously pressed into place well enough, and I wasn't going to remove them without taking the caliper out and putting it on a bench which I didn't want to get into (bleeding's not my most favourite activity, and besides the shims were not likely to come out unscathed).
Bottom line is, I think there is some build up (corrosion, dirt, dust?) occurring between the calliper and the stainless shims (it has been very wet recently) which is decreasing the guide clearances.
My remedy (I can't advocate this!) was to remove the lacquered finish off thepads, so that the ends were flat. This allowed the pads to move in the guides and my brakes now release effectively, with no binding.
Hope this helps.
Emptygroves
