[cwl1979]

As Richard says its very sensitive, from a commercial standpoint those micro bubbles you see are not worth changing the valve out. You could buy a spare for when it actually fails. Air will be hissing out of the nut in the center where the arm connects to the rubber end, otherwise I'd leave it alone. If you wanna carry spare things though the rubber grommet top and bottom are common failure points. I would get 2 of each. Also get a few of the tiny hose clamps that hold it together. Just my 2 cents worth.