So where does the air go? Wouldn't you have to crack the expansion tank cap or something?

__________________
AlexTheSeal: hack mechanic, inadvertent drifting champ, builder of infernal devices, professional epistemologist

'87 300D Turbo, roadtrip mileage champ (for sale!)
'92 Isuzu Trooper, mudder extraordinaire (for sale!)
'82 Honda Silverwing, cockroach of motorcycles
And various boring daily drivers...