Why brake pads wear uneven?

[lunytnz]

The pads on the front disc brakes on the passenger side are wearing unevenly on my 99 Yukon (5.7L Vortec).

I'm thinking that the most likely cause would be sticking caliper pins, but they seemed to be in pretty good shape when I checked them. A friend mentioned a sticking piston, but I'm not sure how that would cause uneven wear... any other ideas?

I have about 2 mm left on the outboard pad and about 4 mm left on the inboard pad.

[toolsinbox]

Sticking pistons do not allow the pads to retract causing ware. The sticking caliper will show a unusual pad ware compared to other calipers.

The other reason for premature ware is warped rotors.

[Explorer]

Judging by the number of different make vehicles that pass through my home garage, it is a fairly common problem. Main issue seems to be sliders not greased, next is sticking calipers, third is collapsing brake hoses.

[lunytnz]

... Main issue seems to be sliders not greased ...

I was wondering about that, in particular. By 'sliders', do you mean the caliper pins? Or, do you mean the surfaces where the assembly that holds the pads slides on the fixed caliper frame? I greased the frame surfaces, as well, but I could feel a small ridge on one of them.

 

I have about 180,000 miles on the truck, so I'm wondering if it's as simple as just smoothing out the ridge when I replace the pads, or if it's just time to replace the entire caliper assembly?

[00Silverado4x4]

Yes sliders are the caliper pins. When I do a brake job on any vehicle I'll pull the calipers apart, clean the pins and regrease before reassembly.

[Explorer]

The last set of calipers I bought came with all new shields and pins. Oldest son replaced his and came with caliper alone. I think he bought the cheapest ones listed. I didn't buy anything special, just stayed with OE replacement.