I'm wondering if the pump assembly I bought way back was an older model toilet?
I'd bet that's the problem. I don't know how long "way back" is...but you could have gotten a very early version of the HF (mfrs do tweak equipment as years pass) or even its predecessor, the HE.
As for a replacement... For a 35' boat, I'd go with the Raritan PH SuperFlush, the current version of the tried and true PHII...they renamed it when they redesigned the base (ONLY the base, the pump is still the same PHII) to fit the mounting bolt pattern for most other manual toilets. But whether it is or not, I recommend filling and re-tapping the bolt holes because bolt diameter tolerances brand-brand can vary over the decades, leaving you with a wobbly toilet if the new ones are even a fraction of a milimeter smaller than the existing holes.
You will love the PHII...it's consistantly been the top rated manual toilet because the diameter of the piston in most manual toilets is 1.75"...the diameter of the piston in the Raritan PHII is 2.5". When you calculate the cubic inch capacity (displacement) of the PHII with a 2 1/2" diameter piston, it comes out to a little over 12 cubic inches. If you do the same calculation for a pump with a 1 3/4" diameter piston with the same stroke, the cubic inch capacity is only 6 cubic inches...which means the PHII can move twice as much per stroke as other manual toilets.
Plus, it will easily last 20+ years if you just keep it well lubricated, replace the joker valve at least annually and put a rebuild kit (about $60) in it every 5-6 years.
I searched for it on the sbo.com store...no joy. This retailer has it for the best price I've found:
Boatersland Raritan PH SuperFlush Toilet
And btw...if you're pouring fresh water into your toilet to avoid the sea water odor and mineral buildup issues, there's a much easier way that works on most boats on which the toilet and head sink are on the same side of the keel:
Sink drain thru-hulls are below the waterline on almost all sailboats. So, unless your boat is the exception, re-route the toilet intake hose to tee or wye it into the sink drain line as close to the seacock as possible because the connection must be below waterline to work.
This will allow you to flush normally with sea water. After you’ve closed the sink drain seacock in preparation to close up the boat (you do close all seacocks before leaving the boat to sit??) or as often as you want to, fill the sink with clean fresh water and flush the toilet. Because the seacock is closed, the toilet will draw the water out of the sink, rinsing the sea water out of the entire system—intake line, pump, channel in the rim of the bowl and the discharge line,(Water poured into the bowl only rinses out the toilet discharge line). Or you can keep the sink drain seacock closed except when it's needed to drain the sink and flush with fresh water down the sink all the time...your choice.
It may also be necessary to keep the sink plugged except when in use, with a rubber sink plug or by installing a conveniently located shut-off valve in the drain hose. Otherwise the toilet may pull air through the sink when you try to flush, preventing the pump from priming.
--Peggie
