Annual Marine Toilet Rebuild

Yes, annual. Why? Because I don’t want to have to rebuild it in an emergency – been there/done that/didn’t like it. So every year I rebuild or service the marine toilet at the beginning of the season, and since I’ve started that, I never have problems with it. This is also the optimal time to service the head, as it has been cleared and pumped clean for winter storage.

I purchased a service kit from Jabsco for my model and year-range. The kit includes three major components, and a bunch of other little parts – all (more or less) critical to the operation of the toilet. There are three main valves that control directional flow of waste: the “joker” valve; the “flapper” at the base of the pump; and the control valves in the top of the pump. They look like this:

Joker valve – positioned at the pump exhaust – keeps waste from flowing back into the toilet.

Flapper at the base of the toilet. Flat side of the valve must positioned in the down position. This model toilet is designed with tabs that will only accept the valve in the correct orientation.

These valves in the top of the pump control the flush water inlet and pump-dry circuits.

My first step was to get a bucket half-full of soapy water – this is where the disassembled parts go. Second step was to put on latex gloves.

Reduces the “yuck factor” considerably.

Next step was to collect more than enough rags for the job. I always need to sop up water and catch drips. Some folks use paper towels, and I usually do too, but didn’t have a full roll on hand (it’s not unusual to use a full roll during the rebuild or service). Okay – now I’m ready to take it apart. I use three different screw drivers for this: a long Phillips, a short Phillips, and a regular flat-blade (medium). Four Phillips screws hold the pump on the stand, and 2 large regular screws attach it to the exhaust hose. There are also intake and exhaust hoses for the flush water.

Remove the screws at the base.

This is the exhaust hose with two mounting screws – the joker valve (below) is inserted in the hose vanes-first.

With the fasteners removed, I took out the joker valve and flapper and inspected them. They were still in good shape, so have been saved with my toilet rebuild spares for emergency use – or give-away in case another cruiser needs them. Note: cleaning fluids like bleach, Spic&Span, Ammonia etc., can ruin these rubber parts in just one season –  this is also true of the alcohol-based antifreeze. I’ve stopped using these cleaning products to clean the head. Since I knew I would replace all the parts inside the head this spring, for ease of winterizing I used the regular RV antifreeze last winter. I use dish soap to clean the toilet when necessary, as it’s a glycerin-based soap that’s easy on rubber parts.

It’s impossible to get all the liquid out of the pump, so I kept it positioned over some rags as I moved it about, and disassembled it. I took out the six screws that hold the top of the pump on, and removed the one-piece valve/gasket for replacement (see above for photo of the valve).

The plunger is removable from the top piece by unscrewing the handle – necessary to replace the plunger gasket.

The gasket surrounds the rod aperture, visible from the bottom (not shown). The circular plastic bearing (left of the pump top) is included in the kit.

The plunger has an O-ring to replace, which restores the pump’s seal in the cylinder. The O-ring is installed with petroleum jelly, according to the instructions. The bore of the cylinder is also lubricated with petroleum jelly, and helps maintain the seal of the plunger.

I replaced the top valve with the supplied part – fortunately with this pump, it can only fit in one direction. With the old Wilcox-Crittendon head that was in the boat before, it was possible to orient the valve/seal upside down and backwards because there were no orientation guides molded into the plastic housing. Of course, if it’s possible to do it wrong, I obligingly did so every time I rebuilt that head ( = extra time to rebuild for assembly-disassembly-reassembly correctly).

Okay, it’s got all the new parts installed – replaced the O-rings supplied with the kit, etc. Now reassembly, installation and testing. This head comes with a good set of instructions, and reasonably good illustrations.  Nothing like photos, though. . .

This time, I read the instructions where they say to attach the exhaust hose first – ah, that makes sense – especially considering how much difficulty I’ve had in the past getting that part to align and seal properly after reattaching the pump to the base first. . . Amazing how much good, helpful information can sometimes be found in the instructions. . .   My wife would be proud of me. Reassembly was the easiest I ever remember this time.

I reattached the flush feed/exhaust hoses, then opened the flush-water seacock for a test run. After 8-10 pumps with a fully drawing/evacuating pump, there were no leaks to be found. Success! Let the cruising begin!

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