Tank valves
my 05 Durango has the gray/black valves mounted inside a compartment- The valves then have a long cable which runs to where the tanks are. The valves feel like they don't close all the way any longer ...
Forum Discussion
Your T handles are probably mounted through the frame. On the back side of the frame is one problem area. Look at a pic from Valterra on the assembly. The other problem area is where the cable meets the valve, could be a loose connection. Shouldn't need to change out the gate valve for either of these problems.
