Grinding Noise

[rapposm]

I have a 1998 Jimmy and the rear brakes were replaced 6 months ago, but the rotors were not. The rotors did have some surface rust that I thought the new pads would fix, which the new pads did not.

Well just this weekend I heard some grinding from the back driver side, looking at the rim I notice a lot of rust or brake dust, could this be that I wore out the pads or that the pads are now making better contact with the rotor and is resurfacing it now?

Please help, it is could to work on the truck in the winter months.

[CanukGMC]

After the first time you used the brakes to do a real stop (more than 2feet) it should have removed the rust, the contact pressure and friction going on between the rotors surface and your pad is far more than needed to remove surface based rust. My shot in the dark is this, maybe the rear caliper was seizing up and not actually being used all the time, hence why the rust remained even after normal braking, did you notice the braking seeming weak or strange at some point in time? If it was seizing and not closing then it's also possible when it finally did close when braking that it partially seized shut so now it's dragging on the rotor burning the face off the pad and causing all that brake dust you see. In a rear wheel drive vehicle it's harder (not impossible though I assure you) to notice if the back brakes semi-seize up like that because the driving wheels are in the rear turning through the friction rather than the front wheels dragging a locked tire (which is very noticeable).

PS ALWAYS ALWAYS ALWAYS machine your rotors AT THE VERY LEAST when you replace ANY pads if you can't afford new rotors. It just doesn't make sense not to, your brake pads will last half as long if your lucky without fixing that rotors surface. It's cheap, simple, and it's not anymore work than it already was removing the calipers and pads.

[rapposm]

Thanks,

But the grinding noise is only heard when I come to a complete stop, could it still be the stuck caliper?

[CanukGMC]

Originally Posted by rapposm

Thanks,

But the grinding noise is only heard when I come to a complete stop, could it still be the stuck caliper?

Could be, is the rust still on the rotor? If so then the caliper is not closing all the way. Jack up the rear end and try turn the wheel by hand (truck in neutral of course, or both wheels off the ground, don't forget jack stands) and see if it's dragging on the rotor. On the other hand the grinding could just be that the pad is pretty well in bad shape because the rotors were not machined when they were replaced or that the rotor has now warped nicely.