I just bought my 04 lb7 duramax a couple months ago and I've had major fuel problems since. I've ran fuel additive, changed my filter, and had 3 metal fuel lines by the tank replaced since I bought the truck. I just noticed today that everytime I blow a fuel line my truck blows alot of white smoke out of the exhaust. I checked and sure enough I have another fuel line leak above the tank. My uncle seems to think the lines are rubbing on something and making them weak but idk what the deal is. I don't wanna keep replacing a fuel line every month. If anyone would know why I keep getting leaky fuel lines and sucking air into the lines creating white smoke please help me out! Thanks.