Rear Brake rubbing

[DirectorOfChaos]

So I just changed my rear pads about 2 months ago. My pads are already gone. When I changed my pads, I also rebuilt the rear caliper and replaced all the seals. But I could still hear the pads rubbing on the disk when I was riding. Seems like the inside pad is not retracting back into the caliper when released.

Any solutions? I am about to change the pads and rotor again and would like to not have to replace them again in 2 months. The pistons in the caliper seem clean and unmarred.

[mstngsrule68]

seems more like a caliper issue

[Wild-Bill]

Are the spring clips installed right? When you rebuilt the caliper did you hone the cylinder and sand down the piston?

[rexazz2]

put the caliper pins in your drill and clean with fine sand paper or steel wool
Are you using a good quality pad ?

[hardlydangerous]

The rotor has nothing to do with it.
You likely need to replace the pins, clips etc also rebuild the master cylinder as well.
the kits are cheap.
Make sure the pads fit on the pins. sometimes paint buildup on the new pards will make then stick on the pins and they fit too tight and bind up.
I would pull the caliper apart again and clean up the piston bores incase they are slightly corroded. Also dont forget to check the pad pins for notching or wear. they should be replaced every other time you replace your pads.
replace the retainer clips. The rounder the contact edges the less friction and the easier things move.
Remember to coat the pad pins with good silicone synthrtic grease or anti seize

[paul.miner]

If your pads have been rubbing, make sure your rotor isn't warped/coned from all the heat. Put a straight-edge across it and make sure it's perfectly flat.

[mstngsrule68]

oh thought of another thing, dont rule out a brake line as well buddy.

[Wild-Bill]

oh thought of another thing, dont rule out a brake line as well buddy.

And then there's the master cylinder, too. Just occurred to me that I've heard of that being the culprit when the brakes won't release properly. It's possible that if it was a long time since the last time you flushed out the brake lines you may have some junk clogging things up in there.

[ckenwright]

Also make sure the master cylinder is releasing the pressure when the handle is released.

[DirectorOfChaos]

Are the spring clips installed right? When you rebuilt the caliper did you hone the cylinder and sand down the piston?

Yup, I sanded clean the pistons and installed the clips right. The pistons were actually pretty clean to start with.

And then there's the master cylinder, too. Just occurred to me that I've heard of that being the culprit when the brakes won't release properly. It's possible that if it was a long time since the last time you flushed out the brake lines you may have some junk clogging things up in there.

Master cylinder is good. No problem there. Same with the brake lines.

If your pads have been rubbing, make sure your rotor isn't warped/coned from all the heat. Put a straight-edge across it and make sure it's perfectly flat.

I definitely need a new rotor.

The rotor has nothing to do with it.
You likely need to replace the pins, clips etc also rebuild the master cylinder as well.
the kits are cheap.
Make sure the pads fit on the pins. sometimes paint buildup on the new pards will make then stick on the pins and they fit too tight and bind up.
I would pull the caliper apart again and clean up the piston bores incase they are slightly corroded. Also dont forget to check the pad pins for notching or wear. they should be replaced every other time you replace your pads.
replace the retainer clips. The rounder the contact edges the less friction and the easier things move.
Remember to coat the pad pins with good silicone synthrtic grease or anti seize

I'm thinking the problem is probably the pins & clip. On review, I think I forgot to grease the backs of the pads when I installed them too. I will order a new set of pins and clips. I replaced the seals last time I replaced the pads. Is is really necessary to replace the seals this time too? They are only 2 months old. Also, any suggestions to a specific rebuild kit to buy? Perhaps a link? 1998 Katana here.

[hardlydangerous]

you may not need to replace the seals... if you do use OEM

I would start by just replacing the pins and clips. use an anti squeal compound on the backs of the pads. its tacky and helps the pads stick to the pistons and pulls them back off the rotor.

[DirectorOfChaos]

I just removed the brake pads to install new ones and found this...

The piston was actually worn down. Now I have to replace the pistons too...

Grr.

[scottynoface]

That's not what I think it is...is it?

[hardlydangerous]

wow, replace it all.

seriously a caliper that hot will be ruined, the pistons will be warped out of round and chances are scored up and the bores out of round as well.
find a used caliper and rotor, rebuild the master cylinder to.
The master cylinder is designed to draw the pistons back slightly when you let off. if its not coming back chances are the caliper is shot or the master cyl was not performing properly and ruined the caliper.
Also if the bore or piston are out of spec the piston can bind up in the caliper bore causing it to drag.
replace the caliper, rotor, and rebuild the master cyl

[DirectorOfChaos]

Nice Bike Hardlydangerous.

Yeah, the pins were pretty corroded and had grooves in them. I think they were what was keeping the pad from retracting back into the caliper. I think my master cylinder is okay, it seems to be working okay, and the opposite side pad was retracting fine.

I'm replacing the pads, seals, pins, and clips. Next time, I'll replace the rotor. I don't want to replace my rotor now only to find that this happens again and eats the crap out of it.