tbb2

I noticed rust on the bottom portion of the right rear wheel rim.
I pulled the rear wheel and there is what everyone suspected - worn out inside pad bearing on the rotor.
The outside pad is still good to go. Caliper pins working fine.

What happened to the squealing from the wear warning tab?!!!?

Lessons Learned:
- If you ask someone to listen for a noise do not say what, why or where. They may just agree with you.
- If you hear a dragging sound related to braking - check all the wheels in order of diminishing suspicion.
- When you do tire rotation and check the break pads,
... but forget to look at the pads on the right rear before having the van up on the opposite side ...
---- DO NOT assume all the pads are wearing evenly. ... Just kick me.

The only good news it the rotor was at the end of its life.
-----------------------
Replacement Materials?
ACDelco or what?

canucklehead

I don't think the rear pads have squealers.....but I may be wrong.

When you put on your new rear rotors, make sure you adjust your parking brake shoes before mounting the caliper bracket. just spin a nut on to hold the rotor.

I am glad you found the issue.

I use ac delco pads, and there are lots of decent oem rotors to choose from. Your local parts store will have a good better best suggestion.

tbb2

I got parts in and started to take the right rear wheel brakes apart for repair and to find why the inside pad wore out so soon.

All on-line recommendations are that uneven wear is due to stuck caliper slide pins.
I started to do the basic checks for stuck pins by compressing the pistons about 3/16" with a C-clamp.
The caliper body slides back and forth just fine. I got distracted from checking pins individually when I found the below.

The outside pad is seized in the bracket slide. But how would this cause the inside pad to wear out first?
The inside pad was loose. The outside pad has another 1/16" wear on it and the inside is gone.
I imagine the caliper would still pull from the outside pad to the rotor as it pushes on the inside pad.

I'm thinking this has something to do with the pad being locked to the bracket and not allowing the caliper to float evenly over the rotor,
but just not seeing it.
This is keeping me awake.

Is this another false symptom?
Is my understanding of the caliper wrong?

Thank you

tbb2

I think a nights sleep reset my brain.
So does this seem correct:
The outside pad is seized in the slides so it is held at a fixed distance to the rotor.
The caliper slide pins are working so the inboard pad is pushed to the inside face of the rotor.
This puts pressure on the inside pad and inside of rotor and the inside pad is then doing 100% of the stopping instead of just 50%.
The outside pad wear is fixed by its distance to the rotor. It can not wear because it can not being pulled in.

This whole exercise has expanded my understanding of "checking the brakes".

mountainmanjoe

The inner pad is actuated by the cylinder. The slide pins allow the outside pad to make contact.

canucklehead

The outside pad slides.....the inner pad rests on the caliper bracket. When you apply braking, the piston pushes the outside pad towards the rotor causing the caliper to slide pulling the inner pad to the rotor. As they make contact the caliper slides balancing the contact on both sides. If the outer pad is not sliding, then the inner pad is the only pad doing the braking, it needs to slide to allow for it to wear evenly with the inner and allow for equal brake pressure on both sides of the rotor.

mountainmanjoe

Here's a better video.



If the slides are seized, then it seems to me that only the inner pad will push against the rotor.

tbb2

canucklehead:
We seem to be in agreement.

mountianmanjoe:
We seem to be in agreement.
The rotor and bracket being fixed in relation to one another was why I was confused last night.

mountainmanjoe

If you can't get the caliper to move freely then just replace it. Rebuilt ones are inexpensive.

canucklehead

You just need to get that old pad and retailer clip out of the caliper bracket. Once the pads are out, and you wire brush all the surfaces, you can install new clips and pads. Just remember that I got a factory set of AC Delco pads for my 13 and the pads were so tight in the clips that they would not go into place without driving them in. There is no way that those pads would have slid in the clips. I had to grind down the wing tips of the pads a bit to make them just snug. First time ever I have seen that.
Do the removal while the bracket is still on the van. It would suck to wrestle that on the bench.
Then remove the bracket and re and re the rotors. New rotors need to be fully cleaned off with brake cleaner. There is a coating on them that will smoke and stink if you forget.
Once the bracket is back on, lube the contact points on the pads, slides etc. and install your brakes.
I like to wire brush and put a small bit of grease on all my threads and lug nuts. Just to make sure nothing ever seizes on in the future.