Thursday, February 19, 2015

Every Cruiser's Favorite Subject

Ok, maybe not favorite subject...but one that seems to be blogged about on a semi-regular basis. Actually, it is probably the bane of most cruisers existences.  Yes, I'm talking about the loo...the porcelain throne...the potty...the john...the porcelain god...the marine head.  During my last trip, the head decided that it didn't want to empty.  Of course, this happened while I was not on watch and was trying to get a little sleep...and anything that results in interrupting my sleep gets promoted pretty high on my repair list.

So, today I did a little research based on the symptoms and found that some people had the exact same problem.  The problem was that when you tried to pump the toilet dry, the pump was hard to push and the bowl didn't drain.  At the time it seemed to me that maybe a line was blocked...but having just replaced the lines, this seemed strange.  What I found was that the lever that switches from wet to dry was reported to be the culprit.  I go down and fiddle with the switch and, if I held it all the way to the right it would work.  I'm starting to see why Jabsco has such a bad reputation with manual pump heads.

The crappy (excuse the pun) Jabsco Pump

I already had a gasket kit for the pump (a set of gaskets that cost about half the price of a whole new head, mind you), so I decided I would rebuild it and see if that wouldn't make it happy.  I've never done this and there isn't much information on the procedure, all I found was the "exploded parts view" for guidance.

The rectangular gasket with corroded brass weights.

I started by removing the pump handle and seal cap.  I then removed the 6 screws that hold on the top of the pump.  Inside that I found several parts that were included in the kit.  There was a rectangular gasket that had brass weights on it, a spring, and the O ring that seals around the wet/dry lever.  I remove the lever and replace the O ring, swap out the spring, and install the rectangular gasket.  I re-install the cover using a relatively standard tightening pattern for items with gaskets.

The upper assembly with the switch lever and spring

I then remove the lower pump housing from the toilet base.  There I found the other rectangular gasket that has a big rubber flap.  I replace that  and carefully tighten the screws so the gasket seals properly.  Adjacent to this gasket is the housing for the joker valve, and I replace it next.  Whoever named this thing the joker valve has an obvious sense of humor as the joker is clearly whomever has to replace the thing.

The last item was to replace the O ring on the pump piston.  I replace it and lubricate the piston with silicone grease before re-installing it in the pump assembly.  With everything reassembled, I test the pump.  It again seems to work, but about one in every 10 pumps or so it fails to pull any water out of the bowl.  Geesh.  On the bright side, at least I didn't have to disconnect any hoses,

While doing research, I found that there is a kit you can buy from Raritan that allows you to reuse the Jabsco porcelain bowl but replaces the whole pump assembly and base with theirs.  Raritan seems to have a much better reputation, so next time one of these pumps gives me troubles I think I will go that route.  I've had enough of these temperamental Jabsco heads and their overpriced gasket set.


  1. If you are so inclined, you can buy a whole pump assembly on Amazon for about what the rebuild kit costs. That's what I carry for a spare. Yes, they are pieces of 'crap'.

    1. Yeah, I know. Kinda hate the idea of throwing even more plastic I think I'll just do it once and get the Raritan Lower Base Assembly kit. It may cost more, but I hope the lower aggravation level will be worth it. :-)