Jabsco Water Pump

[sihall]

Hi, I own a 2000 SO 40 and have a strange issue with the water pump. If using the forward tank the system primes ok, if I switch to the aft tank the system will not prime.
I can undo the pump outlet and air escapes, water then starts to fill the filter, once a tap opens water will flow for a while with lots of air then it will stop and the pump tries to prime again.
If I then release the pump outlet again the process starts again. My first thought is perhaps the pump needs replacing as nothing has changed on the boat, before doing so I would appreciate any other thoughts / ideas.
Thanks for reading.
Simon

[Trevor]

Hello sihall,

I know this sounds silly but have you simply opened a tap and left it open continuously when trying to prime the aft tank?

I would open a tap or two and leave it like that for a long time to allow the air to escape. It may take quite a while for it to push all of the air out of the lines.

Regards,

Trevor

[sailbleu]

Simon ,

probably you have a major leak in the suction of the aft tank.
Could be the manifold or a hoseclamp.
Not sure where your boat is located , but when the temp is rather low I would heat up (heatgun) all the connections one by one and tighten everything.
Heat is neccesary to soften the hose a bit for tightning.

Regards

[aussieodyssey]

Simon

You may have a blocked vent on the back tank .

Greg

[sihall]

Jan 30, 2014 10:12:26 GMT Trevor said:

Hello sihall,

I know this sounds silly but have you simply opened a tap and left it open continuously when trying to prime the aft tank?

I would open a tap or two and leave it like that for a long time to allow the air to escape. It may take quite a while for it to push all of the air out of the lines.

Regards,

Trevor

Thanks Trevor, I have had the tap in the galley and both heads open for approx 5 mins still no change. I will look at the tank vent as suggested.
Regards
Simon

[sitara]

Hi Simon,
Check the inline filter, I have heard of more recent Jeanneaus that have suffered cracks in the plastic filter cover letting air into the system.

[super g]

Quick tests I would do is first try running the pump with the aft tank deck filler cap open as it will act as breather- if this works then tank breather is suspect.

If that makes no difference and if the bow tank is empty then I would fill it up and get it running on that then switch the valves over to the stern tank. If this fixes it then the cut off valve is suspect. It is just possible the valve is faulty and you are drawing in air from the empty tank.



Let us know the cause when you've Suss'd it.

[sihall]

Feb 11, 2014 20:45:32 GMT super g said:

Quick tests I would do is first try running the pump with the aft tank deck filler cap open as it will act as breather- if this works then tank breather is suspect.

If that makes no difference and if the bow tank is empty then I would fill it up and get it running on that then switch the valves over to the stern tank. If this fixes it then the cut off valve is suspect. It is just possible the valve is faulty and you are drawing in air from the empty tank.



Let us know the cause when you've Suss'd it.

I have since checked all connections from the aft tank and valves. I suspect the pump as there was no suction until it was stripped. Reassembled and the pump now has suction will be refitting this week so will let you know.
Thanks