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

Just curious: what made you think you had to drop the underbelly? Is your pump down there? (Mine isn't)

me2 wrote:
Update...I just happened to notice...about 10 minutes from dropping the tank when I discovered this... not been interrupted...

This is Wonderful! Sounds like Divine Intervention!

Let alone, you would have done "whatever" underneath and still not caught the problem at the pump connection...

Update.

I just happened to notice that the fitting that connected the pump to the fresh water storage tank wasn't quite right. Upon closer inspection I found a hairline crack which must have gotten bigger when the fitting was tightened.

I changed the fitting and now I have no further issues. Everything works perfectly.

I was about 10 minutes from dropping the tank when I discovered this. Actually I probably would have dropped the tank the day before had I not been interrupted.

Im not sure if this applies, but have you pulled the conical screen cover on your city water inlet? Sometimes if that small valve fails under the screen it will allow air to enter the system and the pump may be pulling air into the lines. Just another place to check.

I had a similar problem last year when squirrels ate some of my organically produced hose which ran from the tank to the pump inlet. I guess green products can be pretty tasty.

Unlike some installs mentioned here, I had a separate barbed hose tap low on the side of the FW tank close to the drain hose. Dropping the chloroplast involved removing the many self tapping screws and it came right down. There was a 1 inch layer of Fiberglas insulation which also dropped down. The FW tank was accessible for repair.

I spliced in some new hose and was able to replace the partially eaten barbed hose tap at the tank. I also tightened up the drain hose assembly while I was down there.

I bought new self tapping screws and fender washers for the reinstall because the old ones were pretty rusty and some had broke. I had some help from the DW getting everything back up in place. I used the original holes except for the screws that had broken.

Harvey51 wrote:
I'm no expert but perhaps my experience will be helpful. My pump gradually took longer to prime after draining and filling. It got so I had to park on a slope and fill to overflowing on the high end. I told this story to the guy at the RV store and he said the rubber part in the pump needed to be replaced. I don't recall the name but it was a palm sized circular thing. Sure enough it worked perfectly with that new part.

This doesn't seem to be a pump problem. The pump works fine when pumping from a jug on the ground.

I recently read a post here where someone had left his valve in the winterizing position for sucking antifreeze from a jug instead of from the water tank.

That isn't my case. I have bypassed all the input valving and am sucking straight from the fw tank.

I'm no expert but perhaps my experience will be helpful. My pump gradually took longer to prime after draining and filling. It got so I had to park on a slope and fill to overflowing on the high end. I told this story to the guy at the RV store and he said the rubber part in the pump needed to be replaced. I don't recall the name but it was a palm sized circular thing. Sure enough it worked perfectly with that new part.

I recently read a post here where someone had left his valve in the winterizing position for sucking antifreeze from a jug instead of from the water tank.

j-d wrote:
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.

Hmmm...

So last season the pump was taking longer and longer to pressure up after a water draw. And it would lose cycle in the middle of the night when there was no water being used. I thought the pump head was worn.

So this spring the first time out, the pump won't prime at all. I disassembled the pump head and everything and it looked great. After a bunch of testing, I connected the suction side of the pump to a pail and then it worked great. The pump never cycles and it pressures up immediately. So there has probably been a problem on the suction side since new.

The big question for me is why did this get much worse over winter. I totally drained the FW tank last fall. Was there water in the pickup and now it is cracked ?

How big of a job is it to totally drop a FW tank ?

sch911 wrote:
Could there be a hole in the suction line inside the tank that when exposed above the water level sucks air? Sorta like a drinking straw with a hole in it.

It sucks are even when the tank is totally full.

Could there be a hole in the suction line inside the tank that when exposed above the water level sucks air? Sorta like a drinking straw with a hole in it.