definitely take them apart and clean if yhou use ring free. i use ring free and 2s and my valves are clean. but i started doing it myself because the last time the dealer did it it was adjusted too tight and pulled my cables, valves were clean. cost me 3 valves and 1 cable. it's easy too clean (see tech section) and if i screw it up it's my fault and wont feel so bad about buying valves. i had about 1500 mi on them when last pulled apart.