Jabsco problem

Manual Jabsco. Pumps out fine, but wont suck in the salt water. The line to the thru hull is clear. Is this a sign that the "duck" valve is faulty or should I be looking at something else? Any info would be appreciated, Thanks

Jabsco manual head?
Air leak on seawater inlet line or the plunger flap stuck open somehow.

I would check the O-rings and seals. Mine had wouldn't suck as the o-ring on rubber at the bottom of the plunger arm was old and worn out, replaced it and it works like new.

You can buy the entire pump assembly for about $70. That's not a lot more than the rebuild kit and it's just a few screws and you're done. No mess and no chance of doing something wrong.

BTW: Check that the thru hull isn't blocked first.

May I jump in with a related question. My holding tank is almost half full. When I went to empty it offshore last weekend the pump ran but pumped nothing overboard. It was running dry. I guess the line to the pump is clogged. Is there a chemical or something I can add to the tank to liquify everything? Marina pump out machine is down. Any suggestions appreciated.

Pluto said:

May I jump in with a related question. My holding tank is almost half full. When I went to empty it offshore last weekend the pump ran but pumped nothing overboard. It was running dry. I guess the line to the pump is clogged. Is there a chemical or something I can add to the tank to liquify everything? Marina pump out machine is down. Any suggestions appreciated.

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My personal experience with Jabsco waste transfer macerators is there is no such thing as a run dry unit. Replace it with a SeaLand transfer pump and the only thing you will have to do in the future is replace the duckbills. Only one set is needed on the transfer pump. As far as additives make sure your holding tank gets plenty of O2 then no additives are needed.
Bill

I'm with Ron. Don't spend a lot of time trying to fix the pump, just replace it.
You do have the Flush Control Lever in the open position?

You've already checked to see if there is a blockage in the intake hose.

It's unlikely but check for a blockage in the hose between the pump and the bowl.

Unscrew the top cover and take a look at the intake valve. There is a cam that holds the intake valve shut to allow you to pump the bowl dry. It may be damaged and holding the valve shut.

If you haven't fixed it by now, replace the pump.

Here is a link to the instructions and parts list if you don't have them already.
http://www.xylemflowcontrol.com/files/29090_29120-3000_43000-0905.pdf

Pluto said:

May I jump in with a related question. My holding tank is almost half full. When I went to empty it offshore last weekend the pump ran but pumped nothing overboard. It was running dry. I guess the line to the pump is clogged. Is there a chemical or something I can add to the tank to liquify everything? Marina pump out machine is down. Any suggestions appreciated.

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There is not a chemical that you can add to the tank to liquefy everything.

I'm going to assume that you have not flushed anything that you didn't eat or drink first except marine or single ply toilet paper. If you tried to pump out (with the macerator pump) shortly after taking a dump (there's no better way of saying it), the paper or solids might not have had a chance to dissolve and could be clogging the outlet from the tank or the pump itself.

Wait a day or so and try again. Or, using a hose that you do not also use for drinking water, try to backflush through the overboard discharge thru hull. Of course you can't easily do this if it's underwater.

Another thought - is there a seacock on the overboard flush and is it open?

Good points Ron, I once somehow had a bottle cap stuck in my seacock for the waste discharge. I have ni idea how it got past the PuraSan to the holding tank.
Bill

Is the macerater pump used to empty toilet? If so is it possible that you have a gravity dump holding tank that has been left on open discharge?
I also had a pump installed once where the installer reversed the motor wires causing the pump to pump water in...not out.....but I guess that would be obvious....and messy.

Bill Ranson said:

............... I also had a pump installed once where the installer reversed the motor wires causing the pump to pump water in...not out......

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That's pathetic. You would expect people to test their work after doing it.

Manual Jabsco. Pumps out fine, but wont suck in the salt water. The line to the thru hull is clear. Is this a sign that the "duck" valve is faulty or should I be looking at something else? Any info would be appreciated

If you stored it over the winter with the wet/dry lever in the dry position, that put a crinkle in the flapper valve at the top of the pump...a new flapper is cheap and should solve the problem.

My holding tank is almost half full. When I went to empty it offshore last weekend the pump ran but pumped nothing overboard. It was running dry

10-1 odds that your tank vent is blocked, causing the pump to pull a vacuum. Clearing the vent should solve the problem. I wouldn't use the toilet again till you do, 'cuz flushing against a blocked tank vent pressurizes the tank and plumbing, which can have some very nasty consequences.

(Recovering from glaucoma surgery on one eye yesterday and have to stay quiet for a few days, so have some time on my hands to try to help out a bit on a couple of sites).

My holding tank is almost half full. When I went to empty it offshore last weekend the pump ran but pumped nothing overboard. It was running dry

10-1 odds that your tank vent is blocked, causing the pump to pull a vacuum. Clearing the vent should solve the problem. I wouldn't use the toilet again till you do, 'cuz flushing against a blocked tank vent pressurizes the tank and plumbing, which can have some very nasty consequences.

I hate to disagree with the mistress of waste , but my guess would be a macerator or discharge pump located dry above the waste that has a hunk of something that keeps it from pumping.

Depending on the pump location (height vs waste in box) simply filling the holding tank thru the deck fitting with a pail should get it working.

Most discharge pumps are very poor (Obendorfer and Galley Maid excluded) at suction and a tiny scrap will stop the lift.

(Recovering from glaucoma surgery on one eye yesterday and have to stay quiet for a few days, so have some time on my hands to try to help out a bit on a couple of sites).[/QUOTE]


Here's to wishing you a speedy recovery.

HeadMistress said:

10-1 odds that your tank vent is blocked, causing the pump to pull a vacuum. Clearing the vent should solve the problem.

Click to expand...

And if there's a filter in the vent line, that may be the source of the blockage.

Those filters fail immediately if they get wet. Since mine screw on I loosen up the fitting and would see if that relieves the problem. In my case it didn't the pumps impeller was destroyed. I got rid of the Jabsco years ago replaced it with a SeaLand. I've had no issues since the replacement.
You should have 2 tank vents if possible this keeps the good bugs alive in the holding tank.
Bill