Head Games

[Meriachee]

Yesterday our almost new head started acting up. The pump handle works just fine on the "inlet" setting, but when you flip it over to the "outlet" setting and try to evacuate the bowl, the plunger will not go down, due to some serious air pressure resistance.
It almost doesn't make sense, it's the same plunger, the inlet side is pumping to the holding tank, there's no blockage in the tank vent or pump-out hose, and yet the handle "feels" like there's a big wad of something in the barrel when you try to press it down. If you hold it, air gets past the seal and bubbles into the bowl.
Short of disassembling it to see what's going in, does anybody have any ideas?
Cheers
Gary

 

[Ron20324]

The little lever that switches between wet bowl and dry bowl is probably not all the way over to the dry setting to pump out. If you move it to wet then right back to dry, it may work. Or, hold it by hand to the dry for the first stroke, and it will work. Mine does this, and this is what we do for the once-in-a-while occurence. Otherwise, if it never pumps, then the valve inside is not working properly.

 

[Gunni]

How do you know you have no blockages? Have you disassembled the pump? You should be able to field strip that thing in the dark and have it apart in 5 minutes. A dinghy pump and PVC plumbing parts can confirm your hoses are clear.

 

[SycloneDriver]

Mine does the same thing. Just hold the lever over as Ron suggested, works for me.

 

[Meriachee]

We're going out this evening. I will give that a try. Being almost brand new, it hasn't yet been through a complete dis-assembly, and it might be nice, maybe once, to put something on the boat that doesn't require a microscopic inspection of every individual part before doing so.
And, for the record, I know that there's no blockage, and exercising some rare restraint, I'll spare anyone reading these posts from explaining how I know.

 

[bananabender56]

So this is a new problem ?

 

[kloudie1]

Yeah, either the wet/dry valve cam is not going all the way over or there is a piece of schmutz in the valve.. try holding the lever over carefully and if that doesn't work, you can carefully disassemble the valve body cover and clear the little piece of seagrass or snail or whatever from the valve. The cam is notorious for breaking so be careful. There is a screw that holds the cam to the lever... try tightening this carefully before doing anything else.

 

[koolfrog]

Check the holding tank vent line...it may be blocked.Blow some air through the end of the vent line ( use you mouth (pewwww!) or your dinghy inflator pump , or.....)and close your head's lid ! ( don't ask....)
If your vent line is plugged , or restricted , it will create enough back pressure into your outlet pipe to restrict the motion of your plunger.

 

[Meriachee]

Holding the lever over works. That, and the fact that it appears to be a little sloppy suggests that disassembly is in order.

 

[woodster]

this must be a jabsco head?????????

 

[thinwater]

Also consider an inlet strainer. We cruise some heavy sea grass areas, and were always getting grass and stuff in the valve and in the bowl rim.

This set-up also allows for easy winterizing. In this case, the strainer is above the waterline, mostly to make it easy to reach.

 

[kloudie1]

Ya noticed in my post that I used "carefully" a lot.. When you start the re-assembly of the top cover, I find it useful to turn the screws counterclockwise until you feel a vertical "click" then tighten clockwise.. This makes sure the screw goes back into the same threads in the lower plastic housing. This is quick and easy if the bowl has been pumped out .. Good luck Gary.. Proceed carefully!

EDIT: I carry an entire pump ready to go so if there is an issue, I can pull the old one and replace with a known fresh one and then rebuild the old one when I get to it. I found a new pump to be not much more than the rebuild kit:
http://www.ebay.com/itm/Jabsco-Manu...05&prg=10284&rk=6&rkt=6&sd=161060380296&rt=nc

 

[rtshinn]

Marine Toilet Tech leaves a lot to be desired

 

[Gunni]

Yes, having a spare pump on hand makes the job quick and easy, and you can then rebuild pumps at home, at your leisure. A rebuild kit costs about $50.