[Paul erithwc]

I have a 12v 100psi 5.2lpm Shurflo Diaphragm Pump but i have noticed over the last month or so that once the water goes below the pump height and i get air in the hose from moving the van the pump has issues getting rid of the air lock is this a sigh of the pump packing up  

Or could it just be due to doubling the length of hose between the pump and the tank outlet due to fitting a 350 ltr tank  

The pump isn't noisy im wondering if the Diaphragm needs replacing 

Thanks Paul

[Ian Lancaster]

If the pump runs well when the tank's full, it's ok.

We used to have priming problems when the water level dropped below the level of the pump intake.  The answer is to mount the pump as low as possible, preferrably below the level of the bottom of the tank.  If that's not feasible you can prime the pump by sucking through the outlet side while the pump is running - beware when it primes though, you could get a soaking

[Tom White]

I had this problem too.  Fit the pump so it's as close to the floor of the van as possible.

[Don Kee]

Fit this to the outlet of your tank:
http://www.purefreedom.co.uk/small-tank-outlet-fittings-kit-p-371.html

When your water is low and you move the van then switch your pump of and close the tap on the tap. Should stop air getting into the pump while driving

If its doing it while stationary then park so the water is directed to the outlet or get a bigger tank if possible...

As ian said, mount the pump as low to the floor as possible, with as less connectors as possible

[Paul erithwc]

Thanks for the replys I'll move the pump lower to the floor at the weekend and fit a tap to the tank outlet aswell.

Thanks Paul

[Plankton]

Had the same problem with my pump box on the trolley. I bought another pump and same thing happened so I ditched the trolley and put the pump on the ground. It drives you mad.

[soapsudtw]

Clean the diaphragm in the pump would be the long term solution!
Diaphrams are like the suckers on a kiddies arrow that will stick to a window but not granmars head.
if they ain't clean they won't suck

[robert mitchell]

above is exactly what happened to mine , little bits of grit . slightly fiddly yo clean out but only a 15-20 min job .