Howard:
Many of us have been through this challenge. Some people remove the head sink and reach in there to access the hose and the vented loop that is just under the counter. Others cut an access panel next to the head in the side of the head cabinet give you full access to the hidden hoses and the screwed in vented loop fitting. The head hose goes down into the head floor then turns 180 degrees going vertical up and under the head countertop. Then, when built with the countertop off, the factory screwed in a vented loop fitting as high as they could get it. Then they used 5200 and glued the coutertop back down with zero plan to service this loop. From the vented loop/countertop the hose then goes back down into the head cabinet bottom and into the floor coming then into the settee base where you see it coming to the holding tank.
So, to make access to all this easier, I did cut the cabinet access panel and I also cut the base of the head cabinet. Be very careful when cutting or drilling into the head cabinet floor because it is against the hull and you can easily drill into the hull.
Bottomline, there is no easy way to do this, but cutting an access panel really makes sense and the factory should have down this from day one. If you do not like cutting in an access then you need to work through the sink. Not an easy aspect.
Hayden
