First thing I would check is to see of the rear rotor is warped. Put the bike on a stand and spin the rear wheel.

Was everything lubed as it went back togeather? Had a truck that did that and they forgot to lube calipers when they put it back togeather!

While checking to see if the rotor is warped apply the brakes (pump a few times) and assure the caliper is releasing. The inside of flexible brake lines can collapse preventing the caliper from properly releasing.

I too would pull the guide pins and make sure they are lubed with pin lube. Could be that they are not sliding smoothly so you keep applying brake until they finally go all the way in.

Bottom line is I would be sure to get this fixed before riding. If you can't find it yourself, go get it checked out at the shop. Brakes tend to be an important feature!!!!!

thanks for all the input guys, but negitive on all, pins are lubed, pad slides are lubed, rotor is not warped, pads and rotor are clean, brakes release immeaditely when letting up on pedal, non of these would appear to be the problem.
still vexed

You might try bleeding the systen, put some new fluid in there.  It could be that the fluid is getting tired and when it heats up, expands too much causing a light pad to rotor drag .  Then when you apply the brakes in a heated condition they will lock up due to the excessive heat. 

Bleed the system, replace with a good quality fluid, check your brake pedal freeplay verify it is in spec, also check and make sure the brake line does not come in contact with a heated component.  If so, re-route it.

It sounds like something is causing the pads to drag on the rotor and is generating too much heat for efficient braking.

Thanx,

jb

I agree with AZ, if you can't find the problem GET IT TO SOMEONE WHO CAN. I have never seen a brake issue get better on its own, and lets hope it doesn't get worse when you need the brakes the most!!!

Pull the pads and take a sanding disc to the leading and trailing edges and bevel them at a 45 degree angle. this will stop the edges from digging in.

you need a caliper rebuild kit... it's probably due and if you have the right tools it's easy.

thanks for all the advice took everything apart cleaned, lubed, reassebled, adjusted tire pressues, and everything seems fine now. I suspect the tire presssure was the biggest but not only culprit. the palce where i had them mounted had 55 lbs in them, reset to factory recomended pressures.