What Ilya's talking about definitely works , I had an Olds that would even be able to "blow the air" right
through a COLD cap , on a completely cold engine , probly a unique case . While doing the process he's saying,you'll get best action if you can raise up the "nose" of the car to guarantee the filler opening is THE highest point for the bubbles to better migrate out that opening. Like a 15+ deg angle ???