rodge70 wrote:perhaps time for a good clean and check every thing moves smoothly,xhould be a simple emough job
Ditto on this one.
I'll be cleaning both calipers on my Tour, soon.
Not sticking, but lots of grime building up around the piston dust covers.
Have you adjusted the lever placement/travel?
I've read on another forum (Chinabikes) where doing this can sometimes push the piston in far enough to prevent the brake fluid from returning to the reservoir. Causes drag and heat build up. Bad enough to lock the rear brake, in that instance.
I know, "Chinabike", but I've got one in the garage. Luckily no problems like this.
Bill