I have a problem with the rear caliper on my 250R. After pressing the lever the piston won't return to its original position. Upon further examination, the pad pins have seized! One
pin cover is missing, but the allen-head bolt is seized, and the other has its pin cover and is seized. Help! I got the machine 3 weeks ago, so it's not my doing. Why didn't the previous owner use anti-seize?

 

Try sticking the caliper in a vise with some wood blocks on both sides to prevent scratching. Use an impact driver to get the small aluminum cap loose. When you put everything back together use never seize or some grease on the threads.
ERIC

 

Check out this site. . . .
http://pub20,ezboard.com/bhondatrx250r
They had a major discussion on this very issue. Look under "tech tips" and you'll find it.
Good luck.

 

I found the post on the other forum, and my problem is slightly different. I am not sure what a pivot pin is, but need to remove one pin plug to get at the main pin, and one pin. Both won't budge.

Is it safe to drench the affected area with penetration oil? Can I damage anything? The pins are located very close to the piston. Will the oil hurt the piston, or might it help the situation (unstick the piston)?

 

Since I have never had a problem with either of my R's brakes, I want to suggest going back to that forum and post your problem there. I have never had to tear apart my calipers.

 

Mike: instead of sending you on a wild goose chase, use penetrating oil and maybe some heat, ie a torch, along with a impact driver. I have one here, if you're ever up this way, ur welcome to borrow it.

 

You can't hurt the caliper by soaking it in penetrating oil, but use the good stuff. Most of that penetrating oil is just kerosene. If all else fails, take it to a machine shop, they will be able to handle it. Good Luck!

 

Thanks for all the help. I'll try your suggestions and report back with my results.

 

I have had the very same problem the you have. It is very hard to get those pins out without causing damage. Try a lot of penetrating oil first and let it sit for awhile. If you can get the caliper into a vise, without damaging it, then try to get the pins out while the caliper is in the vise. If you can't get them out, make sure that you go to a reputable machine shop. I had a guy drill a pin out of mine and the caliper came out of his vise and he messed up the threads on the caliper. Just be careful and good luck! By the way, it might be easier to get the pins out if the caliper is still on the bike. It is very hard to clamp the calipers into a vise without over stressing the casting.

 

I picked up an impact driver today, but since I unbolted the caliper, it moves when I strike the impact wrench. I can't reinstall the caliper because the pads are pushing against each other. If absolutely necessary, I will unbolt the brake line and put the caliper in a vise. I don't really want to do that, but it may be the only option.