water cooler

[Carl W.]

Check the photo on Sundown's pump, see the acorn on the side of the pump?
Take the nut off and adjust the threaded stud as this applies pressure on the bypass spring for the pressure relief plunger to control your pressure. Later pumps also have a filter that should be checked.
Unless run dry or with grit or dirt in the coolant these pumps run for many trouble free years.

[Sundown]

Check the photo on Sundown's pump, see the acorn on the side of the pump?
Take the nut off and adjust the threaded stud as this applies pressure on the bypass spring for the pressure relief plunger to control your pressure. Later pumps also have a filter that should be checked.
Unless run dry or with grit or dirt in the coolant these pumps run for many trouble free years.

On mine it is not necessary to remove the acorn nut as there is a hole in the top of it to provide access to the stud. In fact I have a small access hole in the cooler cover so that I can change the flow/pressure without removing the cover (I mounted a 2" PSI guage in the face of the cooler). I run it at 45 PSI and at this pressure it flows about 1.25 qt/min. I can sit at the table and weld aluminum (125~180a) for an hour at a sitting and not have the coolant temprature raise more than 8~10º. Of course I take my time and am not doing production work so it is not an arc-on all the time situation.