Jabsco fresh water pump

[Gzito]

Have a jabsco 46400-9500 fresh water pump that keeps running with a slight hiss at the pump.
Filled water tanks and ran fresh water through system, with the pump switch at the panel on.
Once all lines were filled the pump shut off automatically as it should. After 30 seconds it turned on without opening a faucet. A hiss can be heard at the pump.
No leaks. All hoses are tight.
I also ran a independent line to a bucket from the pump and it still won't stop running unless I shut the power at the electric panel. Otherwise it works fine. Plenty of water pressure.
I bled the lines over and over. No luck. And no leaking.
Any help and info would be appreciated.

 

[Ralph Johnstone]

No leaks. All hoses are tight.

If there are no external leaks, the problem is an internal leak, back through the suction check valve. It may be as simple as a piece of dirt caught in the valve or it may require a valve replacement.

 

[Gzito]

Thanks Ralph.
That might explain the hiss.
I will look into that valve and hopefully be able to doit myself without sending the pump to jabsco.