In your situation, there shouldn't be any air in the air tank.
Disconnect your #6 airline, then the collet is only clipsed into the valve block. You can pry it with a flatscrewdriver, personally i pry it a mano :roll:
Disconnect your #6 airline, then the collet is only clipsed into the valve block. You can pry it with a flatscrewdriver, personally i pry it a mano :roll: