Fuel Tank Vent Roll Over Valve Causing High Tank Vacuum and Fuel Expansion

Combination Fuel Tank Vent and Roll Over Valve was stuck closed causing extreme vacuum to form on gas tank and in the summer, the fuel on a full tank would expand and boil back up the filler neck. Both scenarios very dangerous. The culprit; an almost new Vent/Rollover valve installed with the new tank. Where was it made? Why none other than the Peoples Republic of China. Yay.

[@JuanSanchez-ik7wx]

big job for my 94 f150

[@mkdhdinfiniteendlessconten3873]

Hi. Thanks for watching. Yes, that's fuel injected, so the electric fuel pump and sender are one big unit. The vent/rollover valve might actually be part of that too. Not sure. LMC truck has good illustrated parts breakdowns on line for reference. I often look there and then order from Rock Auto or Parts Geek. This valve that went bad was one I got from LMC. Their sending units are also Chinese junk. Rock Auto and Parts Geek let you see the parts, where they're from, and reviews. My 83 is overall essentially no different than an early 60's truck except the fuel tanks are under the bed instead of behind the seat.

[@JuanSanchez-ik7wx]

@@mkdhdinfiniteendlessconten3873 I do get the same issue with pumps shutting off every 5 seconds. But honestly, its not all stations. 711 is the worst. But when I go to a mobil station, my tank accepts it freely. Weird.

[@mark.r8900]

Great video. I have isolated my connections to my charcoal canister but still unable to put more than 5 litres of gas into tank. The gas just spills out from filler neck. My gas gauge always shows full even with empty tank. Can this tank vent valve be the problem? Any help would be greatly appreciated. Thank you.

[@mkdhdinfiniteendlessconten3873]

Hi. Thanks taking the time to watch and comment. The Vent could indeed be a problem especially with filling the tank, but also there is a plastic corrugated hose inside of the rubber filler neck hose that comes up to filler inlet to vent the pressure when filling. If this is the rear tank the rubber filler neck hose which is also the only tank if a single tank truck has to pass between the top of the frame and the bottom of the bed which is a tight squeeze. Due to age the rubber filler hose could be collapsing or kinking in this area right before it enters the tank. It's really hard to see in this area. I think in the past I've used my phone up in this area to get pics and see what's going on. As for the tank reading full when empty, the sender is the issue. I have several other videos on the gas tanks and senders, fuel selector valve, etc and troubleshooting them. If you go to my channel home (View Channel) you'll find them. You can use resistors in place of the sender to simulate low/half/full tank and see what the gauge does. If you need a new sender, confirm you fuel tank capacity and I'd recommend getting one (or other fuel tank component) through Rock Auto. The ones on LMC are poor quality, but their on line catalog helps determine what tanks for what year you have. I'm curious if you're in Canada since you mentioned litres, not gallons. Let me know what you find out.

[@tykit5474]

Hi Mike !! This is Ty from Lowe’s. How have you been??

[@mkdhdinfiniteendlessconten3873]

Hi. I'm good. Been repairing and building various things and making videos as you've seen with the goal of helping people with similar projects. Hope you're doing well.