For some reason, I have two air compressors (different sizes and kinds), that both have new el cheapo chucks on them. Both refuse to deliver air into "flats".

I theorize that the new chucks won't trigger without some air in the tire.

Is this indication right? Seems like flats don't provide much in the way of stem pressure on their valves. Maybe my chucks don't/can't overcome this.

So, what do I do? Throw the chuck away.......

And, go to what? What kind of gizmo allows you to inflate flat tires? Something that gives a squirt of air, no matter the pressure inside the tire....

Give me ideas/thoughts....