Our Shadow Cruiser had no grey tank. The drain lines from the kitchen and bathroom sink and shower were routed to a single 2" line that in turn ran to the main 3" black drain. That connection was a 3" fitting With a 2" side "y". The black tank knife valve at the top dropping down to where the smaller grey line "y" came into it and the cap on the bottom of the whole thing. One had to be sure to open the garden hose cap on the main 3" fitting cap, or remove the entire 3" end cap and connect the sewer hose to allow the grey water to drain or it backed up into the shower pan. With the garden hose connected it could go into a blue boy or wherever. With the sewer hose connected it would drain wherever the big hose went. That being said, there was no knife valve on the small grey water line to prevent black water invading the grey line when dumping the black tank but that would be a minor fix as those valves are readily available. I fixed the whole issue by disconnecting the small line and routing it with a water fill line to the repurposed blue boy mounted under the truck where the spare tire was previously mounted. We put that up front on the bumper. I added a gate valve on the blue boy to drain it and it is accessible at the left rear fender below the bumper. It rides above the level of the exhaust pipe and rear differential, ample ground clearance. Be happy to send pics via private email as I've never mastered picture posting here.
2004 Chevy 3500 Duramax all stock
1990 950 Shadow Cruiser Hard side multiple add-ons
Ancient Valco 10'x5' John boat
2011 Toyota FJ Cruiser Trail Team
One-eyed Trail Horse and one horse trailer
Rocky, Annie, Muffie traveling Fur Babies
