Extreme inner pad wear, caliper seems fine

[lkrasner]

Put new rear calipers on about 2 years ago after one seemed to be sticking. This was before I really did my own work and it was a shops diagnosis and solution, but the warranty is up. In the last year, the right caliper ate through its inner pad WAY too fast. I replaced the pads, cleaned it all up, and the caliper seemed to be functioning fine. It ate through another one in less than 10k miles, down to the metal, and killed my rotor (once again, the other side and the outside pad is more or less fine, if not slightly more worn than the left side).

What could this be? I'm thinking something lodged in the brake line? Is there anygood way to diagnose this before I just start tearing out the lines and getting into a bunch of work?

 

[mizzouguy]

Slide pins move freely and lubed? Thats the only thing it could be.

 

[lkrasner]

Slide pins move freely and lubed? Thats the only thing it could be.

Yep, it moves just fine by hand.

 

[Goodinblack]

Could be that ^^^^ or even a weak o ring on the piston. May have to replace the caliper itself. Don't have rebuild kits anymore. Also check your lines for kinks etc.

The oring that goes over the piston is what distorts when pedal is applied. When released the oring retracts back to original position and pulls the piston back in. If the rubber is weaker or damaged it won't pull the piston back in.

 

[mizzouguy]

I would probably pull the caliper off again and pull the slide pins out and lube them again anyway, checking for anything like a torn slide pin boot or a bad seal/oring ^^^.

 

[sumo]

You live in a areas salt? I seen in the dealerships were calipers and slide pins are fine. What was causing rapid pad wear was rust build up in the caliper brackets. Rust gets built up in behind the pad tabs and acts like a sticking pin. Remove the brackets and file the brackets and lube the ears with some anti seize

 

[lkrasner]

You live in a areas salt? I seen in the dealerships were calipers and slide pins are fine. What was causing rapid pad wear was rust build up in the caliper brackets. Rust gets built up in behind the pad tabs and acts like a sticking pin. Remove the brackets and file the brackets and lube the ears with some anti seize

Interesting, I'm in Michigan, so certainly used to the salt and rust issues. I'll have to take a look at this. It seems to rapid to be something like that, but I could be wrong.

 

[ScottyBoy]

I agree with Sumo. Clean the caliper AND bracket very well with a drill or grinder with a wire wheel. Then lube it with some anti-seize lubricant, preferably the copper based one if you can find it. I'd also clean and relube the slide pins as well. Don't just add grease, clean them off and add all new grease. Check it again in a week or two. If that doesn't seem to work after about a week or two driving, then I would go ahead and replace the calipers.

 

[lkrasner]

I agree with Sumo. Clean the caliper AND bracket very well with a drill or grinder with a wire wheel. Then lube it with some anti-seize lubricant, preferably the copper based one if you can find it. I'd also clean and relube the slide pins as well. Don't just add grease, clean them off and add all new grease. Check it again in a week or two. If that doesn't seem to work after about a week or two driving, then I would go ahead and replace the calipers.

I'll give it a shot. I did clean the slides well last time, but I'll do it again. Not sure I'll be able to tell if it's wearing unevenly after that little time, but I guess we will see. Just dont want to keep throwing new pads at it all the time and risk the new rotors.

 

[sumo]

Pads should slide into bracket nice and easy. They should not have to be forced into the bracket or have to be pried out. Also sometimes wirewheels are not enough. I had to use chisel to break apart really bad corrosion/rust to make smooth even surface.

I'll have to make a how to clean brake job