<< When I do this, do I need anything other than a drill to drill the new holes to mount the PHII? I think all the hoses should line up OK and the diameters are the same... What am I missing when I do this, do I need anything other than a drill to drill new holes to mount the PHII? I think all the hoses should line up OK and the diameters are the same...
What am I missing? >>
Cymeyer, you're missing quite a lot. Marine toilets, unlike household toilets, are not drop-in replacements from one model to another. Tomes have been written about this, and have been published on many, many websites and Forums all over the internet. At home, you can remove an American Standard toilet and replace it with a Kohler or other brand, and everything will line up. Not so, with a marine toilet.
Marine toilets are basically pumps. Different manufacturers use different types of pumps to accomplish the job. These pumps are not all laid out the same, nor are they all the same size. So the toilet manufacturer must put the mounting tabs and the hose locations in places on the toilet pumps where they must be, in order to accomplish their assigned function, and adequately support the pump, the bowl, and the other parts of the marine toilet. These locations vary significantly from model to model and from manufacturer to manufacturer.
The best way to approach it, is to remove not only the existing toilet, but the existing hoses as well. Then lay down a nice piece of Starboard, marine plywood, or whatever, to completely cover the area where the toilet had been mounted. Then you set the new toilet in place, and mark where the mounting holes and hoses must go. You drill new pilot holes for the mounting screws, and new holes where the hoses must be run. This gives you a nice, clean, new platform on which to mount the new toilet, and to run hoses and wiring (if it is an electric toilet).
Then, it is best to run brand new hoses, from the supply water through-hull fitting, to the input to the toilet, and from the output from the toilet, to the holding tank.
Unless you are replacing the toilet with the EXACT same make and model from the same manufacturer, the chances of the existing hoses lining up with the new toilet, are ZERO, for the reasons mentioned above. And even if you are replacing the same make and model, from the same manufacturer, and too much time has passed between when the original was built, and the replacement was built, the hoses still may not line up, due to production changes made during the interim period.
