Air compressors are handy for DIYers to have ... Start by unplugging the compressor. Then, open the drain valve at the bottom of the tank to depressurize it. Next, remove the 1/4-in.

In the test, you blow air past the partly open exhaust valve and outward through the port. Normally you have built a device to hold the exhaust valve(s) at the desired lift (just as not all real ...