Why won't my water pump stop if there's no leak ?

[Amica]

Originally Posted by donradcliffe

Before you tear anything apart, try running the pump with faucets full open for 30 seconds to make sure you have purged the air in the system.

Looking through this forum, saw your response, and followed through with your advice-solved our problem, wish I would have seen it sooner! Thank you. Any advice on how to quiet the Jabsco pump down a bit?

[Cheechako]

Originally Posted by Amica

Looking through this forum, saw your response, and followed through with your advice-solved our problem, wish I would have seen it sooner! Thank you. Any advice on how to quiet the Jabsco pump down a bit?

Yep, it's often air in the system. You can try to isolate the pump from any wood panel it may be attached to. It does help in some situations. Others not so much.

[thruska]

Originally Posted by Cheechako

Yep, it's often air in the system. You can try to isolate the pump from any wood panel it may be attached to. It does help in some situations. Others not so much.

Yes it can help. I’d like to add that I would use a soft rubber as opposed to hard rubber. And place substantial piece a foam rubber behind the plywood if possible. The space behind the plywood acts like a speaker box . You can cushion the motor also but insure that it has air circulation to cool. Depending on the position in which it is mounted sometimes affects the noise. Sometimes the hoses make the noise as they rattle against hull or cabinet frames etc.
I once removed the pump from its mount in an rv and set if on a piece of foam rubber cushion, presto no sound at all.
On the other hand , if you have a leak, you won’t know if you can’t hear it. Only your bilge pump will know for sure ...
Good luck!

[jimthesail]

Ahoy !
Had same problem cured by disassembling switch (two Pozidrive screws under blue cap). Between power leads is another screw with two nylon washers. My 'take' is that this screw is adjusted in factory by a spacer between the washers or their pressure checking supply is faulty (I don't in fact believe they are checked by pressure ?) Testing the switch by finger pressure and a continuity tester I found the adjustment very 'iffy. Either something or nothing ! Switch is sealed and suspect contains an over centre device which is manufactured to trip at,say,20psi. Tuned it to trip at lowest possible pressure and eureka, it works well. There is also a small finned 'spinner' in the void above the switch which I may have disturbed too ? Don't quite see what relays and accumulators have to do with the problem, if the pump has a good supply it will either explode calorifier, burst pipes or put taps into orbit ! It does not know what is ahead, only the pressure difference between the vanes and the switch diaphragm ? Beware the diaphragm can go in upside down easily causing a leak !