Anyone familiar with how to access the drain tube for the a/c?
Ain't these the drain tubes?
If they are, I haven’t seen them. Are they under the seat?
You probably have to remove the sheet metal plate under the cab for access. Serial number required for more info.
SIS is a bit ambiguous on this one. Valve #4 is called a check valve and I'll bet it has something to do with the drain system. Hope this helps.
Spot on Cmark.
Did you find them cwallshouse ? My aircon vents are badly leaking out water in my 6t next gen