1.) White Lightening - Clean Streak, $16.00
2.) WD-40 (gallon size metal can), $16.00
3.) Tri-Flow, $8.00
4.) canned air, $2.00
5.) translucent 1 quart container/ lid, $3.00
I had a pair of Shimano Brifters with the right / rear frozen after sitting in the garage all winter. This has happened a few time before.
Step 1: Remove rubber hoods and saturate the internal shifter gears with WL Clean Streak.
Step 2: soak the brifters for 24 hours completely submerged in WD-40 in the translucent 1 quart container with lid (sold where they sell the mineral spirits at Home Depot), and agitate vigorously as many times as possible.
Step 3: Inject a lot of canned air (like you use to clean computers) to purge the now softened old grease out of the gears.
Step 4: Dry them in the sun for a few hours
Step 5: Re-lubricate the gears with a ton of Tri-Flow. Dry and replace hoods.
They now are shifting like new - amazing. I have gotten rid of 3-4 pairs of brifters over the years that I thought were shot, that I know would have been fine if I had done this method. Oh well, hindsight is always 20/20.
From now on all brifters will get this treatment when they start shifting poorly.
Side note; before I filtered the WD-40 back into the can, I soaked about 8 of my extra chains that I had previously cleaned these with gasoline (bad idea, because of the horrible smell - that seems to last permanently). I was amazed at how much gunk and dirt came off this time around. And, I actually like the smell of WD-40.
I let the quart container sit for a day after, and the gunk/ old grease sank the the bottom. I was able to pour almost all of the WD-40 back into the can.
Whatever WD-40 made from, ( http://www.wired.com/science/discoveries/magazine/17-05/st_whatsinside ) the gallon size works perfectly for this "repair"! I realize that I put my stable of brifter equipped bikes through torture in storing them year-round in an unconditioned, separated garage/ shed (with high heat and cold that Maryland brings).
I have heard of people spraying WD-40 into the shifters from the aerosol can (which I tried, without success). I have also read here about how horrible Shimano brifters are , and "thats why there are so many used left/ front shifters on eBay". I have used this on 5-1/2 pairs of Shimano shifters so far, 3 sets are 105 9 speed; 1 is 105 10 speed and 1 is Tiagra 10-speed (and 1/2 is Ultegra 9 speed left). The worst was an ugly 9 speed 10 right/rear that was toatally frozen (shifter clicked but didn't move the cable) - which came back to 100% after the WD-40 bath.
Guys don't hate when the number of "broken" road shift-levers on Craigslist goes down and my stock in WD-40's parent company goes up.
I've been able to restore a couple sets by just flushing with WD-40, front to back.