Can't help you any with Y pipe, but I think Hunter11 already did.
This is what I used for my sewer hose and it works good.
Length of 5in./5in./96in fence post. Purchased at Menards. I put a cap on one end and hinged a cap for the other end. 3/4in. strip of plywood between that and the frame to give it a little room from the tank that is right above it. Then just used handy strap to secure it.
Cut it to length so the caps are outside of the frame. Hose and fittings fit inside real nice.
I also drilled 1/4" holes in the bottom corners on the front and back side for drainage and aeration. Mounted right in front of rear jacks.
I think this was either cwit's or BDLuke's mod.