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me2's avatar
me2
Explorer
Jul 31, 2017

Water pump sucking air ?, best way to drop the underbelly ?

2011 Chaparral 355.

My water pump is sucking air when drawning from the FW tank. I bypassed all the inlet valving and it sucks air right from the suction hose that goes to the FW tank.

I also tested the pump. It works perfectly sucking water from a pail on the ground.

The thing that puzzles me is that the suction hose also appears to be the hose that is used to fill the tank and I can't find any water leaks when I am filling the tank.

So... is it time to drop the underbelly or is something else going on here ?

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  • j-d's avatar
    j-d
    Explorer II
    Jul 31, 2017
    I'm not your underbelly guy, but I've read here, where the pump pickup (suction side) and the tank drain, were T'd into a drain bung at the low point of the tank.

    But the drain valve, the one used to empty the tank for winter, etc. or the hose connections to it, had pinhole leaks. Water might not drip out, but the PUMP could suck Air In. That in turn compromised the operation of the pump.

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