Originally Posted by vpiuva
Get a can of WD-40 and spray and spray and spray into your shifters. After they free up spray with something that is a better lubricant. The WD-40 flush is probably one of your LBSs favorites.
+1
Worked wonders on my older Tiagra levers. I put about half a can of WD40 down there. It's been fine since.