cavitation and pump won't build pressure

[red2.7]

Hi out there
I replaced my shallow well pump to get more pressure to a second floor shower. I bought a 3/4 hp 30/50
red lion from home depot. It is connected to an expansion tank and a 10 ft deep well. The pressure switch closes and then the pump will run on and on and not build pressure. If I shut off the pump for a second or two and restart then, the pressure builds normally . Next time the pressure drops it's the same thing all over again. The pressure side of the pump has a priming port to which I installed a valve to bleed air out and prime but it still goes through the same cycle. Why would shutting off the pump momentarily "fix" the problem ? Anyone had a similar issue? It's spring and the water table is high.

Thanks
Wally

 

[Valveman]

Sounds like you have a suction leak. Probably right where plastic pipe screws to the pump.

 

[Sponsor]

 

[Reach4]

red2.7, try searching this forum for sha ving (without the space) for a method of finding vacuum leaks.

 

[red2.7]

Sounds like you have a suction leak. Probably right where plastic pipe screws to the pump.

You were on the right track with a vacum leak. I re-sealed the threaded fittings and still had the same problem. So I switched from white sealant, cleaned the fittings and used tapeit was better so I knew I was on the right track. I took it all apart again and used tape and sealant and then it was ok.
I did not like the pvc fittings much cause they would thread into the pump and check valve completely by hand. I could not find any 1 1/4 barb fittings in metal so just a ton of tape and sealant did the trick. Thanks for the advice. I will now tackle the other hundred chores around the house.


Wally