[C320-list] Does Your Bilge Pump Suck?

[Dennis Cookson]

For the last few years my Jabsco electric bilge pump has worked invisibly and reliably, and I haven’t had to think about it. However, I had to change it recently when it finally gave up the ghost. I replaced it with a new Jabsco Par-Max4 Model 31705-0092 which is advertised as self-priming up to 2.5m, and comes complete with a Jabsco ‘Pump Gard’ inline strainer. I tested it at home with a bucket of water and it emptied it in no time. But once installed in the boat, although it has worked a couple of times, I cannot seem to get this pump to self-prime even though it is mounted only a foot or so above the bilges, in the port locker. I replaced the inlet hose, changed the filter, and even disconnected the outlet flow but it still refuses to suck. The electrics seem fine and it sounds ok, but it only functions properly when full of water and not air.  

Finally I returned this pump as faulty and got a replacement from the supplier. Again it worked at home, but not in the boat.  I’m on a swinging mooring and need to trust my bilge pump to operate automatically via the float switch. Right now I can’t leave it on the auto setting or it could flatten the battery/burn out before my next visit.   I note that the outlet hose from this pump connects to the rear of the manual bilge pump in the cockpit. That could provide some additional load, but the electric pump doesn’t reliably prime even when its outlet hose is disconnected.  What am I missing? 

I’d be interested to learn which pump models other owners have found to be reliable self-primers.

Dennis Cookson
‘Catalina’ 0577