When you got it all back together and you say its pretty tight. Can you spin it and it will roll freely for a seconed or won't spin freely at all? I know on vehicles if the rubber brake hose is bad it will cause the caliper to stick, you can loosen the bleeder and if that releaves pressure then its your rubber brake line bad if not it's usually the caliper is bad.

 

No, relieving the pressure with the bleeder doesn't help. When you spin the wheel, it will spin about once, and stop, it is so tight. I checked part numbers, and I'm sure I ordered and was sent the right parts.

When I first took it apart, the old piston was tight. Just figured that was an old worn out part. But when I put the new piston back in, it was very tight too. I took the new piston and O-rings back out, and put the new piston in again (without the O-rings). I did this to see if it was still tight. It wasn't. It would turn pretty freely too, so I am sure the caliper isn't warped.

So, it looks like the problem has been there for a long time, but I had just never noticed it. I had noticed the machine was slowing down (wife's Magnum would beat it going down a trail), but I thought it was getting old and slow, and things were just wearing out. Turns out the front end was WAY off because of bad tie rod ends, steering post bushings didn't help, and now I find the brakes are halfway "on" all the time. No wonder it was slow! Replaced steering post bushings and tie rod ends, and trying to finalize these brakes.

Larry

 

I'll try to talk to some friends and see what they think. You say it fits in good without the O-rings are the new O-rings the same thickness as the old ones? Is the caliper good and clean where the O-rings slide? If its dirty it could cause it not to slide back & forth as it should.

 

Yes, the O-rings are the same. I also cleaned out the inside of the caliper carefully with a Q-tip, then lubed it with brake fluid before putting the piston in (lubed the piston too).

Larry

 

If you ask me one rev on the wheel is not too bad for a disk brake. Sounds like you've done everything right. About the only other thing you can do is mic the caliper, the new, and old piston. Compair the numbers and see what you come up with.
If all else fails, and it still bugs you, your going to have to buy a loaded caliper from the factory. Sounds like it won't be much better if any though.