I won't go into the process of changing out the shuttle valve switch (its been done here more than once), but it's a pointless endeavor if you don't replace the plunger seals at the same time. My old SVS had brake fluid inside it, most likely the culprit of it's failure. The source of the fluid is the plunger seals; the only place I found these is Falconworks in Tucson, AZ. $40 + shipping for two little seals, but better than replacing the SVS only to have the "3 Amigos" revisit in a few months.