Rear brakes!

[JackieFan]

Right, after installing the lowering springs in my S12 my rear brakes seem to be locking on a tad.

I got it back up in the air and checked all the hoses and cables and they seemed fine. The hand brake still has a healthy amount of travel in it and the actuator leavers on the callipers can be freely 'wiggled' when not under load.

The issue is compounded by the near side disc which appears to be warped (wheel will rotate relatively freely for about 1/2 of a turn then locks quite tight for the last 1/2) however the offside seems to just be binding all the time.

Any ideas before I take the callipers off and ruin them further by trying to "service" them?