Ultegra brakes quick release arms jamming

[All the gear...]

I have 5yr old ultegra brakes on my commuting bike. When I recently tried to take the back wheel off, the brake release arm didn't move freely and the whole cable fixing bolt and assembly turned as well, twisting the cable. I've tried loosening the small allen bolt on the quick release arm, but this hasn't worked.
I can see that there's a little plate with a hook on it, that should move whilst the cable bolt stays in place, but for some reason they're moving together.

The front brake was working fine, so I loosened it all of to see how the plate and bolt should align. When I tightened it up again, that too was jammed. Stupid is as stupid does....

Before I take the two calipers to pieces and (attempt to) re-assemble them, does anyone have advice?

Thanks!

[Joe_W]

Looking at the explosive view of the 6500 brake http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/BR/EV-BR-6500-1681_v1_m56577569830611830.pdf I'd say the hole of the quick release where the cable fixing bolt sticks through is gummed up. You have already taken it apart, so clean it thoroughly and reassemble. Good luck.

[jr14]

And don't forget grease.

[All the gear...]

Thanks for the posts guys. I've stripped the caliper down and I think it was just several years of commuting grime - had to really force the cable fixing bolt out as it was stuck solid. Cleaned everything up, greased it all (thanks jr14) and it seems to be fine now.
I guess even commuting hack bikes need TLC from time to time...