Changed brake pads, 1 caliper won't release now...

Prepping the SV for sale and I thought I'd throw in some brand new pads I had purchased a while back even though the original pads still had 75% left on them. No issues with the job; pistons on all 3 calipers pushed back in easily. After each caliper was loaded and bolted back up, I pumped the brakes up to extend the pistons and test. After being pumped up, the right front caliper won't disengage so the brake drags. I verified the right left caliper isn't dragging, nor is the rear.

Thought I may have just messed something up so I took the bad caliper off again and re-loaded the pads and re-installed after extending the pistons even further out and cleaning them thoroughly. Same problem. I've done brakes a hundred times on cars and never had a problem. This is a garage queen with 15k easy miles since new. Any idea what's going on here?

Thanks!

did you happen to let the caliper hang from the hose or did it fall off the fender while you reached for the pads? Could be a pinched hose, or just dirty pistons. Shoot brake cleaner in between the caliper and piston with pistons pushed it. Then air lightly, then more cleaner. If you have Krytox oil add a couple of drops blow in the space with air. (krytox will not contaminate the brake fluid after the seal runs over it) then pump the pistons out push back in etc. the normal drill.

Update: so I removed the caliper again, and pushed the pistons out further to clean them even better than before. When I extended them as far as I dared, I noticed that on one of the pistons, the seal was pinched and bulging out in a few spots. I have never seen this before. The piston still goes in and out smoothly and doesn't leak but it strikes me as odd. Guess I'll end up replacing the seals to start with.

Update: stripped down the caliper, polished the bores and pistons, cleaned and reseated the dust seals, reassembled. Piston action is good on both. Problem persists. Will look at replacing the hose next.

Which seal was pinched? There is a chance that if the outer one was iffy, you're also having a problem with the inner one and to change that you'll have to take out the piston. Not that unusual with bikes, especially in wet climates.

Update: So I rebuilt the caliper on the side that had the problem with all new seals. Put it back together with new pads, cleaned and lubed everything, re-assembled, and it's still binding, just a bit less than before.

Noticed something else odd. Where the front left caliper stays fixed in place when you squeeze the brake lever, the right (bad) caliper appears to pivot a bit on the hanger and at the same time the rotor flexes on that side. Uh oh. So I took a look at the original pads I had removed. They still have 75% left in them, but upon closer inspection the wear was tapered top-to-bottom. Measured the rotor next - yep, it's tapered too, just not enough to see with the naked eye. So it looks like this seal may have been bad when it left the factory and everything has just worn slightly funny since day 1.

Anyway, it looks like some fresh rotors will fix the problem. I don't really want to keep pouring money into this bike as the only reason I'm going over it now is to get it ready to sell, but I'm the kind of guy that wants it to be perfect for the next owner. Especially where safety is concerned. Off to the Internet I go for more parts!

A hose can collapse inside and then act as a check valve when the pedal is depressed holding the fluid pressure against the piston.

RE: the caliper wearing unevenly and the rotor flexing. Are there some bushings that the caliper rides on? Are they single piston calipers or multi-piston?

I thought about the possibility of the hose being collapsed but when I removed the pads and stuck a piece of wood in there and pulled the brake lever, the dual pistons came out, and both went back in when I released the lever so I'm guessing it's okay. I can also push both pistons back in by hand without needing a c-clamp or anything.

There aren't any bushings that I can tell, just a hanger bolted that bolts to the fork and two sliders which are both lubed and move freely.

Holy cow rotors are expensive compared to cars :/

Did it work before you changed the pads? If so, it isn't likely that the rotors are all of the sudden bad. Swap the calipers side to side. I know it won't work, but it will tell you if the caliper or line is bad.

It did "work" before I changed pads but the front brakes pulsed a little which is what prompted me to service them in the first place. When I looked at the OEM pads that came out of the FR caliper and noticed that the wear was uneven; one pad was worn heavily on the top but not the bottom and the opposing pad was worn heavily on the bottom but not the top. I suspected that maybe the rotor had worn funny as well so I mic'd out the outer/middle/inside face and it seems to be within spec.

The most telling thing now is that when applying the front brake, the left side caliper and rotor is perfectly stationary, but the right caliper seems to twist and the rotor flexes a small amount. Not sure what this means. The slide pins seem to be working fine, nothing binding up. Could the hanger/pins be bent somehow? This bike has had nothing but an easy life, always garaged, never ridden in the weather, etc. so I'm really surprised the brakes were all jacked up at only 15k miles.

I'm kind of at a loss right now. If I spin the front tire it only goes 1/4 a revolution before stopping. My only thought now is to just ride it a bit and bed the pads in and maybe the issue will go away but the caliper/rotor flexing like that makes me doubtful.

Is your rotor connected to the rotor hub with small spools? often theses hang up there supposed to let the dick float even with a piston on each side lots of rotors have the spools Ducati's are famous for brake shutter when the spools become dirty and sticky. some MFG have allen wrench holes in them so you can spin them while shooting with brake cleaner.

Yea the, the rotor looks just like this:

Thanks for the advice, I'll see if I can't clean them up a bit.

Yup there's your problem the disks are supposed to float on them. Some guys lube them, but I do not the forces fling off any lube fast and it will attract brake dust.

An SV isn't going to have floating rotors. A GSXR isn't going to have floating rotors. Those buttons are just to hold the stainless disk to the aluminum carrier, not to compensate for out of flat disks or heat. I had full floating rotors in the past, the button was different then these.

I just had my Ducati in the shop for the 15k mile service and asked them to look at the disks as I get some noticeable pulsing. They said they were fine. I just checked and no one of the buttons moves even slightly. Same with my wife's bike. And believe me, the Ducati shop isn't going to NOT sell me something I even slightly need.

The weird brake pad wear is not something that would be caused by the rotor being warped unless it was concave, but then you would be able to see that if the pads were noticeably worn weird. It is most likely due to the pads not sliding in the caliper when the piston moves. Is there something in the one caliper that is causing the pads not to slide? You said the pins were fine. Something where the little tangs on the pads fit? Is there a flat spring on the caliper? I had a 99 SV650 and don't remember anything unusual about the brakes. If you think it is a rotor, try switching side to side and see if that makes any difference.

You didn't have the front wheel off did you? Maybe have the wheel spacers on the wrong side?

Rusnak. Have you checked over on http://www.ducati.ms/forums/ ? Brake shudder is a huge topic over there along with dealer denial of the problem... Mostly due to lack of a 100% reliable fix.

I had never had the wheel off prior to this problem. I did take it off to remove and measure the rotor this weekend though.

In addition to the usual caliper->hanger sliders, there's a fixed top pin and a removable bottom pin for the pads themselves and they do have to slide across them. I cleaned those pins up and applied a small amount of synthetic caliper grease there just to be safe as well.

Bought a used caliper on eBay, rebuilt and installed it, and the problem is completely gone.

Congratulations!