Jabsco Head

[captden]

Glad we have two heads on board, while out cruising this past winter our aft head stopped working, no big deal still had the forward head so I waited till we got back to the states to deal with it. The problem is the pump wouldn't draw any raw water, I figured all that was needed was a rebuild of the pump. Well after rebuilding the pump it still doesn't draw any raw water. I checked to make sure there wasn't a blockage from the thru hull to the pump which there wasn't took the pump apart and reassembeled again and it still won't draw any raw water. I filled the head with water and the pump did empty the bowl but when I switch the lever to draw water in nothing. It's a jabsco pump and I made sure I rebuilt it with the correct rebuilding kit. How can something so simple be such a pain in the ass. Any ideas?
Captden

[sneuman]

Jabsco heads have a reputation for being problematic. Well deserved, in my opinion. After dealing with two of them on different boats, I have vowed never to have another. They are cheaply built (and to be fair, also cheaply priced), but the seals (and that switch lever) are substandard.

In my experience, it is just not worth buying the rebuild kit since the seals are permanently compromised once you open up the unit.

I would recommend going with virtually any other brand. I have had a Raritan PHII that has been problem-free since I bought it four years ago to replace a problem-plagued Jabsco.

[Seahunter]

Depending on what Jabsco head you have it's cheaper to buy a new one than buy parts an pick through shyte and other unknowns with the chance it still won't work. Besides, if you value your time, re + reing 4 bolts and 2 clamps is quicker than messing around with a pump kit; avoiding the much dreaded "pain in the ass".

[svHyLyte]

Originally Posted by captden

Glad we have two heads on board, while out cruising this past winter our aft head stopped working, no big deal still had the forward head so I waited till we got back to the states to deal with it. The problem is the pump wouldn't draw any raw water, I figured all that was needed was a rebuild of the pump. Well after rebuilding the pump it still doesn't draw any raw water. I checked to make sure there wasn't a blockage from the Thur hull to the pump which there wasn't took the pump apart and reassembeled again and it still won't draw any raw water. I filled the head with water and the pump did empty the bowl but when I switch the lever to draw water in nothing. It's a jabs co pump and I made sure I rebuilt it with the correct rebuilding kit. How can something so simple be such a pain in the ass. Any ideas?
Capt den

I had a similar problem with one of our Brydonboy heads and, once I had confirmed that the water intakr line was not obstructed, I found that the contact point on the wet-bowl/dry-bowl lever had worn down too much to allow the little flapper valve to open properly. I corrected this with a little dab of Marinetex, sanded smooth, on the bronze disc that the lever normally contacts, which solved the problem. (We have enough spare parts to keep our heads runing for several more years but not the replacement lever assembly so the foregoing will be our standard fix.)

FWIW...

[HopCar]

It would help to know the model of the toilet. I think HyLyte is on the right track. Take a look at the wet bowl / dry bowl lever and valve assembly. It could be letting air from the rim of the bowl back into the intake side of the piston. If air is getting in, it will never pump water and it wouldn't affect the discharge side. This is a very common problem. Next time I wouldn't mess with trying to rebuild it. You can buy a whole new pump assembly for the newer Jabsco manual toilets for about $56.00. Two hose clamps, four screws, less than ten minutes and you've got a new toilet.

[Cotemar]

captden,
Just shut the seawater valve and put a cup by the sink that everyone can use to do a fresh water flush. We have two Jabsco Model 29090-3000 and have never used seawater for the last two years. Parts last longer and head smells better (no seaweed in the rim holes).

[sctpc]

Not trying to steal you Thread but
I have the same problem since it cost me 1200 to make the pipes do this it will not suck the water in why? the wholes on top suck air and spurt water and pee on the out side help please I ve been ripped off again I new I should have not got a pro to do it.

[HopCar]

It's hard to tell from your photo but it looks like there is a vented loop in your water intake line. That will let air in just when you want a vacuum in the line to pull in water. Put the small vented loop between the pump and the bowl. Nothing should be coming out the little hole on top of the vented loop. If it is, there is something wrong with the vacuum breaker in the top of the loop. Both vented loops should be above the waterline even when the boat is heeled over.

[zeehag]

your vented loop needs to only be in the larger of the hoses as that is out. in , or smaller hose, will only pull air when looped like that. no vented loop in skinny hose.

[HopCar]

Hi Zeehag, Actually with the type of toilet he has, if the selector lever is left in the wet bowl position, and the toilet is below the water line, a siphon can start and over fill the bowl. The vented loop in the fill side is not a bad idea, it just needs to be on the pressurized side of the pump. It doesn't seem to be a big issue and, as you point out, many people do not use a vented loop on the fill side (small hose).

[MarkJ]

Originally Posted by captden

The problem is the pump wouldn't draw any raw water,

friends just bought a mini pipe router that worked for them.

Have you taken the pip right out and put a hose through it?

If you use the Y Valve, check it to make sure its not stuffed. Mine is now plumbed direct out. (I will have to change this when going to USA). The Y Valve caught a lot of calcium deposits and in using it a large flake blocked it.

I like the Jabscos very much.

[zeehag]

Originally Posted by HopCar

Hi Zeehag, Actually with the type of toilet he has, if the selector lever is left in the wet bowl position, and the toilet is below the water line, a siphon can start and over fill the bowl. The vented loop in the fill side is not a bad idea, it just needs to be on the pressurized side of the pump. It doesn't seem to be a big issue and, as you point out, many people do not use a vented loop on the fill side (small hose).

his is same as mine. i have lived on board and dealt with these since 1990. there is supposed to be NO vented loop in the skinny hose. is SUPPOSED to fill when wet side is turned. you HAVE to remember to turn the damn thing off or sink boat.... sorry. there is NO vented loop in the skinny hose or you will not be able to do the flush correctly, which is turn the lever to wet
pump
turn lever to dry
pump
all is well
\ very very simple.
adding a vented loop to the skinny hose only makes inability to pump water in as was designed to do.

[svHyLyte]

Originally Posted by zeehag

his is same as mine. i have lived on board and dealt with these since 1990. there is supposed to be NO vented loop in the skinny hose. is SUPPOSED to fill when wet side is turned. you HAVE to remember to turn the damn thing off or sink boat.... sorry. there is NO vented loop in the skinny hose or you will not be able to do the flush correctly, which is turn the lever to wet
pump
turn lever to dry
pump
all is well
\ very very simple.
adding a vented loop to the skinny hose only makes inability to pump water in as was designed to do.

We have a small vented loop between the raw water intake and the pump on our forward head. The vent on that loop is fitted with a small tube that runs to a fairly standard vent fitting at the back of the lavatory counter. When one needs to pump water through the head, a turn of the cover on the vent fitting or simply putting one's thumb over it, closes the vent. The rest of the time it remains open preventing any siphon action. If the siphons are allowing water/fluid to escape when the head is pumped, the little duck-bill valves are either blocked or defective and need be cleaned or replaced.

FWIW...

[zeehag]

Originally Posted by svHyLyte

We have a small vented loop between the raw water intake and the pump on our forward head. The vent on that loop is fitted with a small tube that runs to a fairly standard vent fitting at the back of the lavatory counter. When one needs to pump water through the head, a turn of the cover on the vent fitting or simply putting one's thumb over it, closes the vent. The rest of the time it remains open preventing any siphon action. If the siphons are allowing water/fluid to escape when the head is pumped, the little duck-bill valves are either blocked or defective and need be cleaned or replaced.

FWIW...

fwiw--you STILL have to remember to turn the lever.... one lever or another doesnt matter. the simplest and easiest installation is the one i read from the jabsco manual-- no vented loop on the skinny hose. only on the out(fat) hose.

[donradcliffe]

I had the OP's problem, but it only showed up on the tack which put the head on the high side of the boat. Just put in a new pump assembly (I always carry a spare) and problem solved. If you want to spend the time fussing, its probably the wet/dry lever system, but since a new assembly isn't much more than a rebuild kit, why bother.

My experience with the Jabsco heads is that the mean time to failure is about 2 years, same as the Raritan, but a lot cheaper.