Jabsco mod 4405-143a issue

[LEOCAT66]

Just replaced an old leaking PAR pump with a new Jabsco flojet 4405-143a, which we had onboard for this occasion. Still boxed, but not a new purchase. Everything worked fine for two days. Now the pump runs fine with plenty of pressure but will not shut off. The system is holding pressure long after the panel control switch is turned off so I am sure that no leak after the pump is present. Both tanks are full, and no air is present.

I am thinking that it is probably the pressure switch on the pump. Seems strange on a brand new pump. Can anyone think of another possibility?

[colemj]

The pressure switch is the little box on the end of the pump head. You should be able to remove it and test it by pushing on it (it is just a membrane over a spring) to see if doing so stops the pump. There is usually also a screw on this switch that allows you to adjust the cutoff pressure. Perhaps this needs to be backed off. Often times there is a cap over this screw, so if you don't see it, look for a little cap that can be pried off.

Mark

[GordMay]

“Gently separate the switch and switch diaphragm from the pump head and inspect for debris.”
➥ http://www.jabscoshop.com/files/Serv...%20Quad%20.pdf

Note: The built-in bypass valve eliminates the need for an accumulator tank.
Do not install in a system with an accumulator tank. The tank will interfere with the internal bypass valve.

[LEOCAT66]

Thank You Gord. The pump has no manual in the box, maybe they do not include one. Anyway, the online instructions are very clear. I had searched under Flojet, but not under Jabsco, as I should have.

Thank You again Gord.

colemj, yes I see that there is an adjustment screw, but I will try putting a little pressure with a finger before disconnecting everything as you suggest. They say if you adjust the screw it voids the warranty. I have no warranty anyway so I will probably go for it if the finger works.

Thank You Very Much

[LEOCAT66]

All is well that ends well. Just finished following the instructions presented by Gord and applying the technique from colemj. Again the pump ran fine but then refused to stop once again. It took the screw adjustment, just 1/4 turn out, to cause it to operate consistently as intended.

Happy things worked out but cannot imagine what people do about a needed adjustment on a new pump when there is the posted warning that to adjust is to void the warranty.

Thank you both again, you made my day.

[sailersteve]

Here is just a note ; be careful unplugging the terminal ends on a Jabsco switch . My terminal pulled out of the switch itself . Mine used a Honeywell Micro switch . The switch and part number was discontinued by Honeywell. After a long google search & some calls i found Mouser Electronics could get me a replacement brand of my part number . The switch i think was around $6.00 and sure beat buying a whole new pump . Mine still works fine today . Mine is a different model pump then LEOCAT66 but would not doubt it has a replaceable micro switch. Just saying .