07. Next, we plugged one end of the airline into the 90-degree fitting on the compressor. The airline fittings are push-to-connect fittings, so you simply push the line into the fitting until it bottoms out and it's secured in place. If you need to remove or replace the airline you just push down on the fitting collar and pull the line out. Legend's uses 5/32-inch (4mm) high temp and high burst airline to help prevent failure.