Author Topic: Jabsco belt driven house water pressure pumps  (Read 2811 times)

Brett

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Jabsco belt driven house water pressure pumps
« on: May 15, 2015, 07:26:13 PM »
Recently, I had  to rebuild our Jabsco belt driven, house water pressure pump.  After reinstalling the pump I could not manage to get the system up to operating pressure.  The pump ran but generated no pressure.  I had assumed there was a leak or air in the system.   After several hours of tracing the waterlines looking for the leaks and bleeding the system repeatedly I gave up and thought I would try a fresh approach the next day.   It was very frustrating.  The next morning I turned the pump on and the system pressurized within 60 seconds.  A tech at a pump rebuilding company told me that despite the fact that the pumps are marketed as "self priming" that in many instances pump is unable to overcome the distance between the water tank and allowing gravity pressure to slowly feed the pump is the easiest way to prime the pump.  I thought this information might save someone else the hours of aggravation in the future.....

Soggy Paws

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Re: Jabsco belt driven house water pressure pumps
« Reply #1 on: May 15, 2015, 09:05:15 PM »
Brett,

Thanks for that info, the tech is right.  We also have that problem from time to time.  But part of the problem is the pump having to work against the pressure in the rest of the system down stream.  Often we can get our more modern Shurflow wobble pump to prime by opening the furthest down stream faucet.   But sometimes if there is a big air stream between the tank and the pump the only way to prime the pump is to remove the downstream hose at the pump so it has no pressure to work against.  That always works.

Another way to help bleed the system of air between the tank and pump is to use the bleed button at the top of a whole house filter positioned in that line.    Ideally the tank should be above the pump and there should be no high loops in the hose between the two that can trap air when the tank runs dry.  We have a high loop with PVC valves for tank and auto/manual pump selection.  I should probably rebuild that manifold and put a bleed valve at the top.   Just what I need another project!

Dave   
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Brett

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Re: Jabsco belt driven house water pressure pumps
« Reply #2 on: May 16, 2015, 06:53:32 AM »
Dave,
I tried all those tricks  this time and none of them seemed to work....I even connected to shore water to bleed the system and it still wasn't enough to get her going.....if there's a bad loop or other design flaw I can just blame Jack...haha

Soggy Paws

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Re: Jabsco belt driven house water pressure pumps
« Reply #3 on: May 16, 2015, 08:07:07 PM »
Brett,

If you have tried ALL of the below options and you are SURE you have all water in the line up to the pump then either the tank is dry or the pump is not working.  You might try a different pump with the downstream hoses disconnected.

Dave
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Brett

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Re: Jabsco belt driven house water pressure pumps
« Reply #4 on: May 17, 2015, 07:07:03 AM »
Dave,
I think you are missing what I'm saying....I got the pump to work...it's just that the usual troubleshooting methods didn't seem to work and letting the system slowly prime itself using the gravity pressure from the tanks solved the problem....I was just putting this out there in case someone else ran into the same issue and maybe I could save them the hours of aggravation I faced....

Peter Roach

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Re: Jabsco belt driven house water pressure pumps
« Reply #5 on: May 17, 2015, 08:14:40 AM »
sometimes when rotary pumps get older the plastic on the housing wear is away just a little bit. This is enough to cause difficulties with priming even with the new impeller.
I tried having a bad day once but I did not like it

Brett

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Re: Jabsco belt driven house water pressure pumps
« Reply #6 on: May 17, 2015, 09:00:48 PM »
Hey Peter,
This one isn't a rotary pump...it's a belt driven plunger/double check valve style....like this

http://www.anchorexpress.com/resize/Shared/images/products/p/229/36800-1000-2T__84918.jpg?lr=t&bw=550&w=550&bh=550&h=550

Peter Roach

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Re: Jabsco belt driven house water pressure pumps
« Reply #7 on: May 19, 2015, 06:44:32 AM »
it should not suffer from the same problem.you might want to mount it lower so it doesn't have to lift as much. Pumps hate the suction side but they don't mind the pumping side nearly as much.you can also try wiping the seals with a little bit of glycerin.
I tried having a bad day once but I did not like it

Brett

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Re: Jabsco belt driven house water pressure pumps
« Reply #8 on: May 20, 2015, 12:41:48 AM »
Peter,
Changing the mounting probably isn't an option for us .....any lower and it would interfere with the diesel pulleys and belts and I don't think I'm up to the task of reconfiguring our water system.....it was bad enough removing and rebuilding the pump.....