I understand the theory about the gas trap. What doesn’t make sense to me is the booster has a check valve which holds vacuum in the booster until the vacuum drops below minimum then open to increase the vacuum in the booster. If the valve is shut closed, how would gas fumes reach the booster.
What makes any sense to me, is it’s there as a failsafe if the check valve fails.
The vacuum line starts at the intake manifold and goes up to a combination inverted trap and check valve, it then heads down the firewall and along the frame to the booster.
By invert loop, do you mean like an inverted ‘U’?
