Trying to help a buddy.

'07 GMC Sierra 1500. Front disc, rear drum.

The passenger front pads are wearing out crazy fast. We just replaced the pads and rotors. Only been 24k since last time it was done. The passenger pads were into the metal. Driver's side had 1/2 pads or better still on them.

The dealer has replaced the caliper's twice and the lines once. He's taken it to 3 mechanics and no one knows what it could be.

We just did the pads, rotors and bled all four wheels. The rotor rotates freely. Truck doesn't pull to one side under braking.

Any ideas? I'm stumped. Could the ABS module do something like this?

 

I don't see how the ABS actuator could be the cause...maybe a worn wheel bearing creating an issue? They replaced the calipers, so the caliper slides should be new too

 

I don't think the ABS has anything to do with this problem. How are the caliper slides? Does the caliper slide freely? The front hubs have a high failure rate around 100K. Also let me tell that there is a huge difference in brake pads. Don't use the AC Delco Durastop pads. They are junk and last about 25K. You need the Factory pads by AC Delco. They come in a plain brown box. These are the best and will last 100K. They do cost a lot more but well worth it.

 

Caliper slides just fine. Like I said, this is the third set of calipers. I thought about wheel bearing, but you think the tires would show uneven wear. They look perfect. I also shook the wheel and it was tight.

He's tried several different pads. They wear normal on the drivers side. Just crazy on the passenger side.

It's done this since new. One test I might try is to let him drive for a while with minimal braking. Then take my IR heat temp gun to see the temp of the two rotors. That should tell me if it is riding with pads touching.

 

May try the rubber brake line.. Could be collapsing

 

The dealer replaced the lines once. No effect. I guess we could put braided ones on.

Thanks for the thoughts.

 

The bearing could be bad and not show any wear on the tire...but if it were bad enough to cause brake pad wear, you would feel play in it and you said that it was tight. I like the heat gun idea, that would at least tell you if something is keeping the caliper piston applied. How many miles are on the truck? Has it ever been in an accident? I'm assuming that the steering components are all tight and not worn?

 

If the pads are wearing unevenly on the same side(inside vs outside), then the caliper is not floating/sliding properly. I think you have a caliper that is not releasing. Take it for a normal drive, and check the temp of the rotor. Or take it for a drive, jack the front up, and see if the wheel turns the same when it is hot. I think that the pads are not releasing the way it should. It sounds like a bad proportioning valve (under the drivers side of the cab). I am not 100% about this, but this seems like the most logical since everything else has been changed.

 

Just to elaborate on what I was saying earlier. I am thinking that the proportioning valve is not letting the fluid flow back through properly to let the pads release off of the rotor. This is something that might not happen when the system is cold. When the brakes are used everything gets hot, even the fluid. When things heat they expand. When the fluid expands it forces the pads to the rotor. You should be able to notice this by turning a wheel by hand cold vs. warm/hot.