Originally Posted by
rpenmanparker
Shimano levers do get gunked up and exhibit such behavior. Have you tried flushing it with WD40?
Wouldn't touch the lever with anything, all 6800 parts are still under warranty (it has 2 years, and even the oldest 6800 is still just under this), would be going back to your reseller/LBS etc for warranty repair/replacement
if it's really failed.