I am having issues with my Mazda 6 brakes and can't quite get my head around the issue.
I was having issues with the rear DS brake, which looked like a stiff slider due to inconsistent pad wear, with the outer pad nearly worn out.
The caliper wasn't looking to good either, so I have replaced the caliper and the caliper carrier, bled the brakes and went for a test drive.
All seemed fine with firm brakes, however when i got back i felt all discs and both the rear DS / front PS were far far hotter than the other discs, indicating that the pads on dragging on these diagonal brakes (I don't know if the front PS brake dragging was a pre-existing issue)
I took the wheels off these hot brakes and checked the sliders (all fine and free) and the caliper retraction, and the front caliper was very stiff, but went in eventually with a G-clamp. The rear goes (new caliper) in stiffly while being twisted (brake fluid reservoir cap on).
It seems that there is an issue with how these diagonal brakes retract, and the brake system allows them to free up a little to release the brake, but not enough that they don't drag, causing the disc to get too hot.
I have read that car brakes work on a diagonal redundancy system, with the two diagonals working on different circuits with the master cylinder having two chambers / pistons. Could it be an issue local to the rear DS / front PS circuit, or a fault with the master cylinder for that circuit.
The other two brakes seem to work fine, with not excessive heat in the discs.
Any ideas on fault finding?