Before starting the head replacement project, I figured it would be a good idea to pump out and rinse the holding tank as much as possible. Unfortunately, the old deck fitting was seized and I could not get it open. When I checked the fuel fill, I saw it was the same kind, so I figured I would replace them both at the same time.
I ordered the parts from Catalina direct, and planned a weekend to do the replacement. I started with the fuel fitting, so I could figure out the process without smelling the holding tank. That turned out to be a good choice, as you will see later.
To get the old parts off, I removed the 3 screws, then tried to push the fitting out from below. No luck. It appears they were put in place with some kind of adhesive. I then used Marine Formula by DeBond. This stuff is magic, and I have since used it for removing all kinds of things that were installed with 3M adhesive. For this stuff to work, it has to contact the adhesive, so I dribble a little bit around the edge, then use a putty knife to gently work it under the fitting. As it dissolves the first layer, it can then come into contact with the next layer. A little patience and slowly working the putty knife in deeper each time, it soon came loose and lifted out.
Once it was out, I test fit the new part, and immediately saw that it was too small and would not cover the old hole. I ended up going to Marine Exchange, which is just a couple of miles from the boat, and bought two new ones that were the correct size.
Putting them back in was pretty easy. First I reattached the hoses (without clamps so it would fit through the hold. Then I packed the under side of the lip with butyl tape, drilled a couple of new screw holes, and screwed it down. Once they were solidly in place, I installed the hose clamps from the under side.
Now I have nice looking deck fills that work smoothly.
