strange problem

[N2HIPSI]

My friend just bought an 87 gn. He is having a problem that we cannot figure out. He is getting gas in his charcoal canister thru the vacuum line. I have never seen or heard of this before. Any suggestions on the cause and the cure?

 

[John Larkin]

They have check valves. Maybe it is malfunctioning. Not sure how it would get pushed that far but you never know.