The pumpout hose is an achilles heel for sure, given that it is never empty, and given that the original hose installed was very poor in terms of being permeable.
Due to the tight bend radius needed to connect to the pump out fitting, the most flexible and least permeable hose is called for. Reinforced butyl rubbers sanitation hose such as Raritan Sani / Flex
http://www.defender.com/product.jsp?path=-1&id=3054300 is an excellent choice.
Now that I know that all 1.5" fittings are not the same size, I wish that I never bought the venerable 148 / VAC XHD hose that I used to replace the other sanitation hoses. The amount that I saved on the 148 was nothing compared to having to put up with the grief of the heat gun, hose lube and hose splitting that I went through.
I considered replacing the tank at that time as well, but am glad that I didn't. Once I cut the original pumpout hose off of it, I found that the tank wasn't leaking.
It was a tough project to start, but one of the most worthwhile improvement projects that I did on Blitz. If you have the opportunity to put a cup of bleach, a cup of laundry detergent and clean water in the tank before sailing the boat one last time before the last pumpout and start of the project, it will make for a very clean tank and a much more pleasant project.
Good luck,
-Chris
