Jabsco Head Pump Stiff

[Halo]

In recent weeks my Jabsco Head pump has got stiffer and stiffer. I purged the outlet line with brick cleaner which made little difference. The log paddle wheel has been fouled by sponge like creatures so I wonder if its the same in the head inlet. Before I start dismantling things is there an easy way to test if its a restriction in the inlet or outlet?

 

[bobgarrett]

Try adding some vegetable oil to the bowl, pump it into the pump and leave it overnight with the handle at the top.

 

[vyv_cox]

Is it stiff on the up, down or both strokes? If only the up it is a problem on the suction side, on the down only it's the discharge, foul, side, if both the piston needs lubrication. Vegetable oil is a very short term solution, just a couple of days. Silicone grease would be a much better solution.

 

[C08]

Apart from the good advice to use a squirt of vegetable oil which I do every week when on the boat the pump out can become stiff when the Joker Valve starts to get hard with a coating of calcium like deposit. A horrible job to clean it and probably better just to fit a new one.

 

[Stork_III]

Lubricate the handle shaft also. Amazing how tightly the O ring seal can grip the shaft when dry.

 

[Plum]

Lubricate the handle shaft also. Amazing how tightly the O ring seal can grip the shaft when dry.

Mine goes stiiff every couple of months, both on up and down stroke, and as above, I grease the shaft seal (mine has a lip seal) as well as the piston o-ring. Always fixes it for me but is quick and easy to do to eliminate these parts if it does not work for you.

Colin. Www.solocoastalsailing.co.uk

 

[KellysEye]

When we were long distance sailing we used th Jabsco loo multiple times a day, whenever it became a bit stiff we put vegetable oil in. As said you can use silicone grease but you have to take the head of the pump off and take the pump out to get the grease in. I did it once and didn't bother again, vegetable oil is easier. If you do take the pump out be very careful putting the screws back to avoid a crossed thread, If you do that you will need a new cylinder and head.

 

[John 32i]

I have a problem with the toilet bowl filling up over a 24 hour period even with the seacock closed, guessing water is running back from the pipe to the holding tank so thinking of adding a valve....never had a holding tank before!

 

[Stork_III]

I have a problem with the toilet bowl filling up over a 24 hour period even with the seacock closed, guessing water is running back from the pipe to the holding tank so thinking of adding a valve....never had a holding tank before!

A twist-n-lock pump would (should) sort that. The joker valve should prevent it, but a the name suggests they like to play games.

 

[laika]

+1 to vyv's post which I think is the answer to Halo's question. If it turns out it's the piston, as others have said, oil is a very short term solution. You really need to take the top of the pump off and grease the barrel. This is the 6 screws on top. Remove those and pull off the top and pull the plunger out of the shaft. Clean round the inside of the barrel then lubricate with vaseline. This is what Jabsco recommends, seems cheaper than silicon grease, and works for me. Assuming all the seals etc. look ok, reassemble. On a modern twist n lock the slightly fiddly bit is making sure the hook bit which switches between flush and discharge is correctly slipped under the flap which makes that changeover happen. Make sure the seal is in the right place and re-insert the screws. As KellysEye said, be very careful not to cross-thread and don't be afraid to take your time, back off and re-insert.

I don't replace the innards every time I do this but if the pump hasn't been serviced for a while it could be handy to have service kit to hand in case it looks fallingaparty.

I've got this down to a fine art now. Even having a couple of goes at getting it all back together, it's less than a half hour job.

I have a problem with the toilet bowl filling up over a 24 hour period even with the seacock closed

Joker valve? Sometimes putting vinegar and/or hot water into the bowl, giving it a couple of pumps and leaving it for a bit can get rid of a bit of calcification and delay having to change the joker valve.

 

[vyv_cox]

I have a problem with the toilet bowl filling up over a 24 hour period even with the seacock closed, guessing water is running back from the pipe to the holding tank so thinking of adding a valve....never had a holding tank before!

This is a typical indication that the joker valve has something between its lips that prevent it from fully closing. The culprit is usually deposits of carbonate salts but can also be other debris. Dosing with hydrochloric acid will often fix it but the best remedy is to remove it and either replace or clean it. With practice this can be done in about ten minutes. I put a plastic bag underneath the fitting before undoing the screws. This catches all the liquid in the upward leg of the loop, avoiding dropping it all over the floor.

 

[vyv_cox]

When we were long distance sailing we used th Jabsco loo multiple times a day, whenever it became a bit stiff we put vegetable oil in. As said you can use silicone grease but you have to take the head of the pump off and take the pump out to get the grease in. I did it once and didn't bother again, vegetable oil is easier. If you do take the pump out be very careful putting the screws back to avoid a crossed thread, If you do that you will need a new cylinder and head.

We live aboard for half the year. When I had a manual pump I reckoned to grease the piston about once every two years, which demonstrates how well doing the job properly can be. I have never needed to put vegetable oil in the bowl, which strikes me as a very hit-or-miss method.

 

[Stork_III]

A modern Pump (last 10 years) has a screw off top to access the pump barrel, no screw removal needed

 

[laika]

A modern Pump (last 10 years) has a screw off top to access the pump barrel, no screw removal needed

Mine is 5 years old. It looked like the top might come off but it doesn't: it's all moulded.

 

[bobgarrett]

We used to grease the piston with Vaseline every few months but found the veg oil cure lasts a few weeks and is less messy and needs no tools.
Agree back filling probably means the joker valve needs replacing.

 

[RichardS]

Mine is 5 years old. It looked like the top might come off but it doesn't: it's all moulded.

Is it Jabsco? We replaced our 8 year old ones with new ones 2 years ago and they all have a screw top just under the handle. If it has a 22/23/24 mm hexagon (I can't remember which) I am sure that it is unscrewable and just looks like it's a molding.

Richard

 

[affinite]

If all above don't work, change the piston O ring.
Worked for me (ours had stretched and was dragging in the cylinder).
Changing it also sorted the backfilling problem we'd had for a while

 

[laika]

Is it Jabsco? We replaced our 8 year old ones with new ones 2 years ago and they all have a screw top just under the handle. If it has a 22/23/24 mm hexagon (I can't remember which) I am sure that it is unscrewable and just looks like it's a molding.

You could be right: I took an adjustable spanner to one a couple of years ago. It wouldn't budge, I thought I might break the plastic and had made a mistake so took the top off instead. Then got into the habit of doing that. I honestly can't remember what it looks like from underneath. I have a new spare pump in reserve so next time I'll put a little more force into it and see if you're right...

 

[laika]

If it has a 22/23/24 mm hexagon (I can't remember which) I am sure that it is unscrewable and just looks like it's a molding.

Duh. Yes. The parts diagram on the twist and lock information sheet very clearly shows that that is a separate part. Thanks for that and sorry to others for early misinformation.

 

[John 32i]

This is a typical indication that the joker valve has something between its lips that prevent it from fully closing. The culprit is usually deposits of carbonate salts but can also be other debris. Dosing with hydrochloric acid will often fix it but the best remedy is to remove it and either replace or clean it. With practice this can be done in about ten minutes. I put a plastic bag underneath the fitting before undoing the screws. This catches all the liquid in the upward leg of the loop, avoiding dropping it all over the floor.

Thanks all for the advice....a new joker valve circa £7 appears to have solved my problem