Rear pads wearing out before the fronts?

[Whamhammer]

A year or two ago, I had all of my pads and rotors replace in my car, just got the oil changed and they did the normal check outs of the vitals, and came back with the front pads being at 10/32 and the rears are at 4/32, anyone ever see anything like this before?

Do our cars have any problems with the load sensing proportioning valves? I just find it really odd that thte rears are so quickly going through pads then the front!

[Naaman]

I was thinking that the proportioning valves could be the culprit, but maybe its something simpler: do the fronts and rears start with the same amount of pad material? If not, perhaps the wear is normal?

[SMWS6TA]

same material thickness = yes.

I agree on the pv setup being the likely issue. It takes time dialing them in right.

[Whamhammer]

same material thickness = yes.

I agree on the pv setup being the likely issue. It takes time dialing them in right.

I thought '02s had Load Sensing Proportioning Valves, I wasnt aware that they were adjustable, manually.

[SMWS6TA]

I'm sorry I think I misread or understood something.

Stock ABS or you are running PV's like I am?

It's two different responses....

[Whamhammer]

I'm sorry I think I misread or understood something.

Stock ABS or you are running PV's like I am?

It's two different responses....

Stock braking with ABS, without Traction Control.

[SMWS6TA]

Same brand for front & rear?

[Whamhammer]

Yup.

[SMWS6TA]

hmm....I'm stumped now....

[Whamhammer]

hmm....I'm stumped now....

Me too. Whatever the problem is, its forcing a bias to the rear brakes.

Its not just one rear pad, so its unlikely a caliper or hardware issue.

I don't have traction control, so its a three channel ABS system, which would link the hydraulics of both sides of the rear together. I dont nnow if there is a valve in the "T" junction for the lines that might make pressure/fluid to flow to the calipers easier than away, increasing rear pressure at a higher rate than the fronts?

These pads were definately on the car when I dynoed it, so there was no drag then, now if it did in the 6/32 worth after the tune, thats a different story but I think that would be fairly obvious to me.

Anyone have access to AllData, or a TSB site?

[sjgreen6]

It is possible that the rubber hose in the rear has deteriorated internally and is holding pressure toward the wheel cylinders. The internal rubber gets soft and starts to act like a one way valve or at least a one way slow restriction when you press on the brakes. The pressure creates enough drag to wear the pads and heat up the rotors but not enough to really feel from the driver's seat. Can't see the deterioration of the hose from the outside. Given the age of our cars, this would be my guess. Swap the rear hose, bleed the brakes all around and see if the problem goes away.

[Zapper2003]

brake stands

[35th-ANV-SS]

brake stands

That was my first guess too. If so, invest in a line lock.

[Whamhammer]

It is possible that the rubber hose in the rear has deteriorated internally and is holding pressure toward the wheel cylinders. The internal rubber gets soft and starts to act like a one way valve or at least a one way slow restriction when you press on the brakes. The pressure creates enough drag to wear the pads and heat up the rotors but not enough to really feel from the driver's seat. Can't see the deterioration of the hose from the outside. Given the age of our cars, this would be my guess. Swap the rear hose, bleed the brakes all around and see if the problem goes away.

I cant remember the serup in the back, is it just one brake hose off of the main line, like the Third Gens?

[35th-ANV-SS]

Yes.

[Whamhammer]

Yes.

Al three rear hoses, pads, brake flush, and parking brake adjust being done on Saturday. We'll see how it goes, maybe I'll pick up a smidge or to of mpg. .

[pajeff02]

I have had what Steve posted happen once on an older GM, so it is possible that a rubber line has collapsed. Other than that, I would suspect that the caliper pins are dried out and sticking when there is unusual brake wear.

[Whamhammer]

I have had what Steve posted happen once on an older GM, so it is possible that a rubber line has collapsed. Other than that, I would suspect that the caliper pins are dried out and sticking when there is unusual brake wear.

With all that I am doing tomorrow (see earlier post), all of those possibilities should be eliminated.

[35th-ANV-SS]

brake stands

This one still stands.

[Whamhammer]

This one still stands.

Except that Ive never done that.