rgwoehr

My brake pads aren't wearing evenly on both sides in the rear. The photo below is of the driver's side caliper, and as you can hopefully see, the inner pad is much thinner towards the rear of the car than it is towards the front. The passenger side was worn the same way, but worse than the drivers side. Both the inner and outer pads are tapered top to bottom as well. I assume this is not normal, so what could be causing the pads to wear like that?

Hammerhead Fred

One or both of the forward pistons are stuck in the caliper bore.
Only the rears are functioning.
New caliper
Rebuild the caliper
Or, "May" get away with just new pads if you can get the piston to move properly. Can sometimes be accomplished by pushing/prying it back into the bore if the bore isn't rusted up. Can test this by opening the bleeder, inserting a new pad (one side at a time) and checking the bore pair for free movement by pressing the pad in and out. If they all move freely then install both pads and bleed the caliper. If you feel the piston bind each time you try to move the pad against it then time for new/rebuilt caliper.

ddawson

Agreed time for a rebuild.

rgwoehr

I pulled off the right rear caliper yesterday. One of the piston seals didn't look too good, so we tore it apart. There was a bit of a lip near the bottom of each bore that the pistons would hang up on when we would press the pistons in. I wouldn't think that would be a huge problem because the pistons don't move that much during operation, but if they wear like that again, I guess that means it's time to replace those calipers. I can't afford to replace those right now so we just put it back together with new seals and put it back on the car. I'll do the other side later today

ddawson

Check Autozone for replacements. With the core it only comes to $39 each.

That's what I'm using. I make sure they are Delco Moraine though castings before I'll accept them.

c3_dk

Rebuild, and go for O-ring.....

mrvette

And obviously replace the pads, and check the rotors to see they not destroyed especially on the inner surface.....check the old pads that they not worn uneven between the inner surfaces and the outer surfaces, talking of the inner circumference vs the outer....I had a pair of rotors destroyed by pads that wore out on the inner/small diameter, and had nearly new looking thickness on the outer edges near the retaining pins....only thing I can say is that it's a crappy design causing even the most REMOTE possibility of that happening.....unless CHINA!!!!

rgwoehr

I checked Autozone and the site says $65+$30 core. That's still not too bad, but for now I'm just gonna rebuild what I have and see if it takes care of it.

I'm replacing the pads, and the rotors looked ok. A bit glazed, but no cracks. I did notice the retaining pin on the passenger side was worn down quite a bit in one spot, not sure if that would cause a problem.

Hammerhead Fred

Pin was likely trapped by the cocked pad. In a perfect world they "float" in the holes and simply keep the pads in place.

doorgunner

On my 1968 project car I noticed that the pads were worn very thin at the bottoms and the tops had very little wear (55,500 miles)
I completely rebuilt the calipers/lightly honed the piston bores.
When I installed the new pads and placed the caliper onto the rotor I noticed the bottoms of the pads fit very tightly against the rotors (rotors were FLAT within .001")......but the tops of the pads had a 1/8" gap between the rotor surface and the pad surface.
Being a machinist I measured the gaps/then resurfaced the caliper mating surfaces.
After reassembling everything the pads made full contact on both faces of the rotor.

I hope the above is not your problem.

rgwoehr

I also hope that isn't the problem with mine. Mine appear to make full contact with the rotor though. I did notice the calipers don't look like they sit square with the rotors though.

My dad rebuilt the drivers side one today. The pads on that side were worse than they appeared



So I'll be ordering new rotors this week because there's a pretty deep groove on that rotor.