hello, i recently installed a Coleman 3/4 HP Shallow Well Jet Pump that i bought at Menard's. that sits in a pump house in my yard. it is used for watering flowers etc. it is a hard plumed setup with a check valve on the suction line, no pressure tank. The discharge line has a T on it with a ball valve on top for priming and a ball valve on the discharge line, The pump has been working great for two weeks, last night i was having trouble with it short cycling, adjusted the switch didn't help tried a new 30/50 pressure switch didn't help. i have replaced the check valve and checked the suction line, pump seals, and discharge line for leaks, none found. The pumping level is also good with clean water all the time. so i put a pressure gauge on it and plugged the pressure switch port, the pump it able to produce 70 psi all day, but when the it is unplugged it drops down to zero psi this is why it short cycles. i have been searching the internet all day and cannot figure out were the pressure is going when it is shut-off. when their are no leaks a new check valve and the discharge tube is closed with a ball valve. the pump only has 5 hours on it
thank you for your help
Last edited by zanderd; 05-28-2013 at 01:14 PM.
I agree you need a pressure tank. What you're trying to do is to compress a liquid. Can't be done.
thank you for your help, their must have been a air pocket under the ball valve/priming port previously because it seemed to cut in and out just fine until i bled the air pocket out, i just need it to cut out when the spray nozzle is closed. do you think i could use a accumulator tank because don't have allot of room to spare and it is only going to be used for lawn care.
Last edited by zanderd; 05-28-2013 at 08:12 PM.