82 XJ750J Maxim Brake caliper touches rotor and drags.

I have an 82 XJ750J maxim. The rotor on the brake lever side is actually dragging on the rotor. The piston side (outside) of the caliper where the brake pad is has a small metal tab and is rubbing on the rotor making a lot of noise while riding or just spinning in the shop. I installed new aftermarket pads and it almost seems like they are too thick - but maybe i am just new at this. What I think is happeneing is that the inside pad will not allow the piston side pad to compress inwards enough and move the caliper off the rotor. I dont know if something is bent or not - but the rotor seems good and I didnt have any issues with it before the pad replacement, so I am trying to diagnose the problem here. Overall, I have recently replaced the pads, the piston seals and the master cylinder. Everything seems to work fine, and I have good pressure and everything now. The piston for sure moves, because I took it off the bike and tried to push the pistion out, and it move quite a bit. So I put it back into the caliper and same thing.

What do you mean 'float' the caliper? Is that a certain way of putting the caliper system back on the bike, and over the rotor? I wonder if I should loosen up the caliper, pressurize the pistion more by squeezing the lever, and then trying to tighten it down on the fork?

any help would be appreciated. I have thought about replacing the pads with a different set, or perhaps sanding/grinding the ones I have down, or even using an old pad with the new pad so i can get some clearance off the rotor.

One last thing, what are the bolts for on the caliper that have the rubber boots on them? There are two of them, with one for sure being on the front of the caliper - facing the front of the bike, near the bottom (they are horizontal when the caliper is on the bike. Under the boot is a nut that looks like it could be adjusted. Is that anything that could be adjusted to open up the caliper just a hair and get the caliper edge off of my rotor?

thanks to anyone that can help me here!!! This has been stressing me out. After all of the advise on here, I can't seem to get my brakes back to normal. I am looking for anything to be a quick fix, or a permanent fix. I really wanted to ride it this weekend with my buds, or when I can get it fixed properly. I dont know what could be causing this, and I am reaching out to you professonals here with all of this awesome knowledge!

thanks again.

 

you need to take the caliper off. and clean up ALL the surfaces that need moving. INCLUDING the bolts. the caliper itself might be working. but if the bolts and everything else is froze. your going to have hard sticking brakes that wear more on one side. the caliper needs to be able to slide back and forth. as it moves on the bracket as the brakes wear down. it doesn't just mount and stay in one position.

the caliper SHOULD move a wiggle as you apply the brake. and it's probably not moving at all.

take the bolts out. clean and grease the bolts using brake antiseize. and clean the mating surfaces between the caliper and the bracket it bolts too.

 

Take a close-up picture and post it so we can see what's rubbing. Sounds like the anti squeal clips are installed wrong. Also, if everything is installed and working properly, there is a relief valve in the master cylinder that allows the pad to back away from the rotor when you stop squeezing the handle. All the caliper guide pins need to move freely without binding also. If the guide pins are corroded and or the pad slide pin is corroded the caliper might be hanging the pad up against the rotor. The pad needs to free float in the guide pin.

 

ski84's advice is spot-on, being as he owns the same bike.

All the XJs use slightly different brakes, although some are shared between models. The 550 brake is not the same as the 650 Max, nor is the 650 Max the same as the 650 Seca.

The advice that applies to all variants is the same though: there is some provision for the caliper to move from side to side. All sliding points/mating surfaces, slide pins, etc., have to be clean; the ones that actually take part in the sliding need to be lubed.

http://www.babbittsonline.com/pages/par ... fault.aspx
Have a look in the fiche, although the picture is REALLY BAD.

And no "quick fixes" allowed on brakes-- your life depends on it.