For starters....

1999 2-door Blazer 4WD
5-speed manual
rear discs
4WAL


The problem that I am having is my Blazer wears out the rear passenger side inside disc pad way too frequently.

I have quite a bit of mechaical background. I had bought the Blazer used, so when the first one went, I assumed it was just time for a brake job. I caught it at the slightest noise, so no rotor damage was done. The driver's side was worn, but not as bad as the passenger side.

So...Just 8,000 miles later - same grinding noise from passenger side rear. First instinct told me that I has a rear caliper sticking to some degree. It never got abnormally hot, nor did it ever smell. However, I decided to do a COMPLETE rear brake job. I replaced pads, rotors, and calipers. The parking brake shoes looked fine, but however I took them apart and cleaned, and lubed and anti-siezed the adjusters and assembled everything back.

Now...here it is....about 10,000 miles later, and I am back to the same old thing. Starting to hear the slight squeal and grinding noise from the passenger rear. Pulled the tire and sure enough....pads are worn out. Outer pad is about twice as thick as the inner (which is darned near into the rivets). The drivers side looks pretty good, about what one should see after 10,000 miles.

For the record, I have not had to do a thing to the front. They look fine, and have plenty of wear left on them.

I have bled all the brakes properly, and am getting fluid to all wheels as I should.

Any ideas? This one has me stumped.

HCII

 

A collapsed flexible brake hose can cause your symptoms. The interior of the hose fails then acts like a hydraulic check valve. That causes the caliper piston to keep some pressure on the pad and wear prematurely. To check the hose, get the rear wheels off of the ground (being safe to chock other wheels and use jack stands, etc.) with the parking brake off. Turn the wheel in question to feel the drag (or not). Apply the hydraulic brake forcefully then release. Recheck the drag. If the drag is noticeable (you may not be able to rotate the wheel), open the brake bleeder valve and recheck the drag. If the drag releases, the flexible hose is likely shot.
Hope this helps and good luck.

 

If a flex hose is restricted, both the inboard and outboard pads will wear, not just one pad.

When serviceing the rear disc brakes on S & T body vehicles, always replace the entire assembly. Caliper, pads, hardware and caliper mounting bracket. Bolt it on and bleed, done!

 

Don't bet on it, but thanks for the input. I'll surely have a new caliper bracket, pins and high temp. synth. grease available during the next tire rotation with brake pad inspection.

 

Captain is correct on the fact that if the flex line were the problem, it would affect both inboard and outboard pads.

I only had to replace the caliper mounting bracket on my old 2k Bravada due to a froze up slider. It was much cheaper and easier than messing around with the old one.

In everything that you replaced, did you ever pull the sliders, clean them, then relubricate them before putting the caliper back on?

 

Yep...

New sliders, boots and bolts came with the caliper. The only thing I did not change was the mount bracket. I took the new sliders, coated them with anti-sieze, and also anti-siezed the bolts that bolt into them..

Any other thing I may be missing?


HCII

 

The proportion valve is putting too much pressure on the rear brakes.

 

The proportioning valve also controls both rear brakes simultaneously, just like the flex hose.

When disc brakes are applied, hydraulic pressure extends the piston outward in the bore of the caliper. As it extends and the pad encounters resistance when contacting the rotor, the caliper slides pull the outboard pad against the rotor. When the hydraulic pressure is released, the piston retracts back into the caliper bore releasing the inboard pad and the slides relax releasing the outboard pad. If the inboard pad wears faster than the outboard pad, the caliper piston is not retracting back into the bore freely when the brakes are released. If an outboard pad wears faster, the hardware is binding.

 

Anti-seize is actually a poor choice for the slider pins. It should not cause problems right away, but I have had to take a few of them apart where someone used anti-seize only to find it caked up in there, not doing a whole lot of good. Caliper grease (high temperature) is what should be used.