Water shut-off issue

I had the same experience when I got the new style pump as a replacement. Very frustrating, I adjusted it using the directions supplied by Old Biscuit and adjusted the screws as much as five turns from the factory settings.

Every time we would go out it would require adjusting again, I even had pressure gauges in line to verify my adjustments.
I was unable to solve the problem until I installed a one gallon accumulator tank.

I then adjusted the pressure side to just 50 pounds to help conserve water when dry camping. I always wanted to try an accumulator tank and I like the way it works, the pump runs on demand and fills the tank and does not run again until it is under demand again.

I still like the old pump better, it was a variable speed and had no short cycling, and certainly would not run with the faucet closed!

Espee wrote:
Thanks Old Biscuit
I looked online at the pdf for my shurflo 4008, and it does state there is both a press switch adjustment, and bypass adjustment. Unfortunately they dont show which is which, or any procedure to adjust the pump.
Does anyone have a method to dealing with their madness?
When I originally installed the new pump it was quick cycling at moderate water flow, which seemed wrong, and was annoying compared to the original shurflo we had. I adjusted what looked to be the pressure switch (when comparing to old pump), and it seemed fine for awhile. Then it occassionaly failed to shut off after water faucet was closed. Readjusting back a bit in between factory setting and my first adjustment seemed to work for awhile until It recently started the "clunk clunk clunk"...
It would be easier to adjust it instead of returning it under warranty, but if thats how they want to play, I suppose we could go that route... but seems stupid, especially because the next one could have the same pathetic settings.

Looking directly at front of pump....
Pressure switch adjustment is the center upper allen screw
Bypass adjustment is lower left allen screw

Try This For making Adjustments

That is water hammer, the sudden top of flowing water. In the fire service, thia can be very dangerous when you have a hose jump violently. You can make or purchase a dampner, it is plumbed in the line vertically and traps an air bubble in it to soften water hammer. Many RV's use an air gap in the water heater to accomplish this as well. I installed a small accumilater tank in our coach. No hammer, and we can run water with out having the pump every time.

Thanks Old Biscuit
I looked online at the pdf for my shurflo 4008, and it does state there is both a press switch adjustment, and bypass adjustment. Unfortunately they dont show which is which, or any procedure to adjust the pump.
Does anyone have a method to dealing with their madness?
When I originally installed the new pump it was quick cycling at moderate water flow, which seemed wrong, and was annoying compared to the original shurflo we had. I adjusted what looked to be the pressure switch (when comparing to old pump), and it seemed fine for awhile. Then it occassionaly failed to shut off after water faucet was closed. Readjusting back a bit in between factory setting and my first adjustment seemed to work for awhile until It recently started the "clunk clunk clunk"...
It would be easier to adjust it instead of returning it under warranty, but if thats how they want to play, I suppose we could go that route... but seems stupid, especially because the next one could have the same pathetic settings.

Recently replaced water pump (did struggle a bit to get its shut-off close to original).


That statement leads me to you have 'pump shut pressure' issue.

Your 2006 model OEM Shurflo is no longer available.....both pumps of that era were discontinued several years ago.
So you replaced it with a current model that has an 'internal' bypass setting/control.
If discharge pressure is changed or bypass setting is changed they can overlap.

Check Shurflo website and download the service manual for your model.

If it is a Shurflo pump it should have a adjustment screw on the end that can be turned no more than one turn CW to keep the pump from surging - they call it "cycling" when a faucet not opened much. Maybe as you close the faucet you getting the cycling.
If that is the pump you have you can download the service manual with pictures and instructions HERE. Go to the bottom right of the 3rd page and look at "Switch Shut Off"