Jabsco Holding tank pump problems

[Chris_Robb]

I have a Jabsco model 50810 -1000 diaphragm pump. It has straight forward valves as used in many pumps.

It refuses to pump out until I undo the tank connection, when it is clearly seen that the valve nearest the tank is puffing and sucking as the pumps runs. I poke a thin plastic tube down through both valves, wikgel around and suddenly the sound changes to suck suck suck, I reconnect whilst pump is still running and the tank empties. I have now had 2 lots of replacement valves and 2 new pumps - all exactly the same.

The pump is so simple, I cannot understand why it does not work 100%.

Has anyone else had the same problems?

Its a right pain in the £rse!

 

[Sandyman]

Sounds like an installation problem.

 

[Chris_Robb]

well - thats what I thought. But they say my install is ok.

Pump is only having to draw up 500mm, so well within spec. So why does it suddenly start to suck when a rod is pushed into the valves?

The only query I had was the the diaphragm motor is under the pump itself, but they say thats fine as it is designed to mount at any angle.

 

[charles_reed]

Firing from the hip, and in the dark.

I had a very similar problem with my Par 3 diaphragm water-pump. For some reason it kept on refusing to start pumping, easily sorted by giving it a kick.
I finally found, the feed-wire, from bus bar to the pump, was suspended over the end of the keel lift arm, which had worn through the insulation and all except one strand of wire. All had tested OK - continuity, volts etc but that one strand just couldn't carry enough current to get the motor up to full speed.

It may be that you have a similar situation - try working it direct from the battery and see if that sorts out the problem.

 

[Chris_Robb]

Firing from the hip, and in the dark.

I had a very similar problem with my Par 3 diaphragm water-pump. For some reason it kept on refusing to start pumping, easily sorted by giving it a kick.
I finally found, the feed-wire, from bus bar to the pump, was suspended over the end of the keel lift arm, which had worn through the insulation and all except one strand of wire. All had tested OK - continuity, volts etc but that one strand just couldn't carry enough current to get the motor up to full speed.

It may be that you have a similar situation - try working it direct from the battery and see if that sorts out the problem.

I have full power to the motor and it puffs away, so I really dont think that is related.

The first valve is just not sealing properly and prodding it from inside does the trick. Taking it apart - all looks OK.

Bloody thing - I will put a macerator in instead!

 

[charles_reed]

With a macerator, don't go to Turkey.

 

[Chris_Robb]

With a macerator, don't go to Turkey.

Why not, its still sh!t, but just more bust up?

 

[charles_reed]

Why not, its still sh!t, but just more bust up?

I think you'll find they're insisting on holding tanks - certainly for black water and, according to the law, grey as well. Macerators are only accepted as an alternative to holding tanks in the USA - I'm not certain the UK Inland Waterways will accept them.

 

[Borden]

Chris
You say 'It refuses to pump out until I undo the tank connection', just another shot in the dark here but are you getting enough air flowing into the tank to replace what's going out? Check the filter on the end of your breather tube. Even a new pump won't suck against a vacuum.

As for macerators. We're in Turkey and the holding tank pump macerates as well as pumps. The big draw back is that when it runs it does sort of advertise what's going on due to the noise.

 

[Chris_Robb]

I think you'll find they're insisting on holding tanks - certainly for black water and, according to the law, grey as well. Macerators are only accepted as an alternative to holding tanks in the USA - I'm not certain the UK Inland Waterways will accept them.

Charles - I have a holding tank, I just need a pump that works 100% of the time! A macerator will also pump.....

 

[Chris_Robb]

Chris
You say 'It refuses to pump out until I undo the tank connection', just another shot in the dark here but are you getting enough air flowing into the tank to replace what's going out? Check the filter on the end of your breather tube. Even a new pump won't suck against a vacuum.

As for macerators. We're in Turkey and the holding tank pump macerates as well as pumps. The big draw back is that when it runs it does sort of advertise what's going on due to the noise.

No problem with an airlock, because once I have induced the pump to suck by poking the valves, it pumps out no problem. Occasionally it does it by itself but thats rare!

 

[prv]

The only query I had was the the diaphragm motor is under the pump itself, but they say thats fine as it is designed to mount at any angle.

I think it's supposed to be mounted with the motor above the pump, but that's more about preventing leaks into the electrics.

Pete

 

[Chris_Robb]

I think it's supposed to be mounted with the motor above the pump, but that's more about preventing leaks into the electrics.

Pete

The instructions say "dont mount vertically with the motor below the diaphram" Mine is mounted Horizontally with the motor underneath, which they say is OK. Agreed that if there is a leak the motor might suffer.

It is such a simple pump, is really frustrating that it does not work properly!

 

[skipklaus]

Had a similar problem with a Johnson Viking Power 16. Reduced the length of the inlet valve by 1 mm and since then, the pump works fine.

 

[Chris_Robb]

Had a similar problem with a Johnson Viking Power 16. Reduced the length of the inlet valve by 1 mm and since then, the pump works fine.

Which end of the inlet valve did to shorten?

 

[skipklaus]

Chris, i'm sorry. Had wrong assumption. Your Jabsco pump has joker valves, whereas the Johnson pump has flapping valves. So my advice does'nt help you. Unfortunately.