Jabsco Water Puppy - self priming?

[Highland laddie]

According to Jabsco the above is self priming up to 1.2m above water surface. However the only way I have managed to get mine to prime is to fill the pump body with white grease and eventually it picks up. The height measurement in my case being 900mm. The impeller is new (and in the right way), so is the cover 'O' ring, the suction side tubing has been replaced and the strum box is clear.
The most annoying part is that left for more than a couple of weeks and the above self priming routine has to be repeated.
Up to now I have focussed on possible installation failings, however I am now becoming sceptical about the 1.2m claim made by Jabsco.
I would be grateful for any advice or comments.
Thanks Gerry

 

[VicS]

I know it! A friend had one in his Westerly. Never really known it to work!

1.2 m maybe when brand spanking new. Not only a new impeller but an unworn pump body.

BUT IIRC they take quite a current, but I cannot access the Jabsco site at the moment to check.

Check that all the connections are good, switch contacts good, contact on fuse good etc etc . don't forget the negative as well.

If the cable run from the supply to the pump is any significant length ... more than say a metre, you will need pretty heavy wiring to avoid excessive volts drop.
Check the volts at the pump. What is the length of the cable from power supply to pump.

Edit Done some quick calcs

Assuming current is 12 amps and a distance of 10 ft you'd need cable that is at least AWG 12 or 3.3 mm² If the cable run is longer you'll need even heavier cable.

It might be possible to introduce a loop in the plumbing to trap water in the pump but I am not sure if that will be good thing to do or not.

 

[jon711]

Isit brand new, or used? If used, turn the faceplate over, if new, there is an air leak in the inlet pipework. The quote of 1.2M is conservative, in test, we saw them prime from far higher...

Jon
(Ex Jabsco Worker)

 

[Highland laddie]

Jabsco pump

Thanks to you both for your advice/comments.
The pump isn't new but has had little use and the cable sizing might well be an issue. It's reassuring to hear that the 1.2m head height is conservative and means I can focus on trying to get the thing to speed up. I am sure that air leakage isn't an issue.
The face plate has an 'O' ring on it's inner face so I don't think loss of suction there is likely.
Thanks again, Gerry

 

[duncan99210]

If there's any sign of wear on the face of the plate, then the impeller will not make a good seal and will fail to prime. Examine the plate carefully and reverse it if there are any scratches. The o ring is there mainly to stop the water getting out rather than to make the seal with the impeller.

 

[Highland laddie]

Jabsco Water Puppy

Duncan, you were spot on, just reversed the faceplate and the pump self primed
Many thanks Gerry

 

[Outwiththewind]

We had the same problem with our Jabsco Puppy Bilge Pump and after changing the impeller, pipes, non-return valve, sanding down the old face cover of the impeller, etc it turns out that just swapping the face cover was the solution.
Thanks guys!