I made a repair for my Great West Van Legend lavatory drain hose. I didn't have a good positive connection and the hose kept slipping off. It is a flexible moving hose connection because the lavatory slides in and out.
This is the drain receiver for the 3/4" flexible corrugated plastic drain hose. It is not a full 3/4" diameter and only protrudes 1/4" which did not provide enough bite to keep the hose attached.
I found this 38 cent PVC 3/4" male adapter at Home Depot and made modifications as you can see in this before and after photo. I cut off the screw thread and had to sand down the male end so the hose could slip over easier. With the threads cut off the adapters inside diameter slides loosely over the protrusion but close enough for the cement to make contact.
The drain pipe is ABS plastic and the adapter is PVC so I bought some Oatey ABS to PVC Transition Solvent Cement and liberally applied to all the contact surfaces. I was rather messy but it isn't suppose to be seen anyway. Solvent cement dissolves the plastic and essentially welds the pieces together rather than just act as a contact cement.
So far it seems to be holding and the corrugated plastic drain hose will definitely not slip off like before. I've looked at several Great West Van solutions for this before my van was built and after. They had seemed to have solved the problem after mine with more positive connections. If anyone has an older Legend with this problem, this is a fix without a lot of major re-work.