I'm trying to replace the Pressure Switch on my CH 631400AJ. I am stumped at how to connect the unloader valve to new switch. I purchased it from AirCompressorPartsOnline. It was supposed to be an exact replacement.

In the picture below, the old unloader valve and tube is shown at left. The new unloader valve, integral to the new switch, is shown at right.

It seems to me that I should just move the tube and fitting to new unloader. However, try as I can, I can't get the fitting and tube out of the old unloader. I tried grabbing the knurled fitting with pliers and pulling but it just wont budge. The fitting does rotate freely, implying to me that there's some kind of latch release, but for the life of me I can't find it.

Is there some secret? Did I buy the wrong part? Did I fail to buy something extra? I feel king of stupid asking this question but I'm stymied (I'm an amateur in these matters).

Another general question: In my research I read that the unloader valve is supposed to vent pressure above the cylinder(s) to the atmosphere when pump stops to allow easier re-starting. But in my case, the tube goes to the main air tank not to atmosphere. Am I totally misunderstanding the operation of this device?

So if I understand correctly, I need a "Quick Connect" (QC) to fit my new unloader, right?
I'm guessing the QC is a small fitting that plugs into the unloader on one end, and has a 1/4" hose bard on the other end?

More Dumb Questions...
1. Just to get my terminology straight: the part I labeled New Unloader in my picture; that is what's actually called the "Unloader Valve" right?
2. The old tube on my compressor is 1/4" O.D.. I suspect it is more like 1/8" I.D.. Is that what you refer to as the "1/4" nylon tube"?
2. If I understand you correctly, the bare tube should press-fit into the unloader valve, correct?. I can't see how that would work because the opening in the new valve is 5/16" (?).

Thanks! The tube *did* press-fit into the new unloader despite my misgivings. I'll give it a try tomorrow.