Gas vent pipe or check valve?

I have a rebuilt engine ready to run. One problem... I get no fuel from my fuel tank. I added 15 gallons to it, and I'm at the tank discharge hose, to the fuel filter. No gas comes out. I blow back through the hose with compressed air, and I can hear it bubbling in the tank. I do not know where the vent or check valve is. Does anyone here know or have some ideas. 1990 Cooper Prowler 10 meter.

A lot of them have a check valve in the fitting on the top of the tank where the fuel hose attaches. It can be inside the 90 degree fitting.

The check valve prevents backflow into the tank, and, properly installed/oriented/operating, will not inhibit flow OUT of the tank.
If you can blow air from the motor side into the tank, the check valve doesn’t work, or more likely, there’s not one there.

Comodave said:

A lot of them have a check valve in the fitting on the top of the tank where the fuel hose attaches. It can be inside the 90 degree fitting.

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The fitting at the tank/fill hose is pretty tough to get at, but in the morning, I will look into it. Thank you.

kapnd said:

The check valve prevents backflow into the tank, and, properly installed/oriented/operating, will not inhibit flow OUT of the tank.
If you can blow air from the motor side into the tank, the check valve doesn’t work, or more likely, there’s not one there.

Click to expand...

If you don't mind me asking...
What do you think is keeping my 15 gallons of gas from flowing out of the tank into my engine fuel filters?

The check valve is more properly called an anti siphon valve. Without suction on the hose the valve should be closed to prevent a siphon in case of the fuel hose becoming disconnected. The valve is usually builtin the fitting on the top of the tank and doesn’t generally show up until you take the fitting off. It is usually very small.

Gasoline tanks usually have an anti-siphon device or a tiny hole near the top of the pickup tube. The fuel pump overcomes the small amount of air the hole allows in. When the pump is off the hole allows the gas in the tube to drain back into the tank, not in the bilge in the case of a leak.

One possibility for no fuel is a rusted off pickup tube. Or more rust holes in the tube than the pump can overcome.

Lepke said:

Gasoline tanks usually have an anti-siphon device or a tiny hole near the top of the pickup tube. The fuel pump overcomes the small amount of air the hole allows in. When the pump is off the hole allows the gas in the tube to drain back into the tank, not in the bilge in the case of a leak.

One possibility for no fuel is a rusted off pickup tube. Or more rust holes in the tube than the pump can overcome.

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I think I got it figured out. Bad check valve.

CooperBrewer said:

I have a rebuilt engine ready to run. One problem... I get no fuel from my fuel tank. I added 15 gallons to it, and I'm at the tank discharge hose, to the fuel filter. No gas comes out. I blow back through the hose with compressed air, and I can hear it bubbling in the tank. I do not know where the vent or check valve is. Does anyone here know or have some ideas. 1990 Cooper Prowler 10 meter.

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Thank you everyone. You got me to looking. I think we got it solved

Many fuel tanks have a pickup connection on the top of the tank and a stand pipe to pick up the fuel from above the tank bottom.The fuel is sucked out by the engine ,siphon action keeps the fuel flowing , if there is no air leak.

Fuel will not flow out of the tank unless the siphon action is started.

The usual check valve hopes to block air from entering the system , while the engine is not running or filters are being serviced.

kapnd said:

The check valve prevents backflow into the tank, and, properly installed/oriented/operating, will not inhibit flow OUT of the tank.
If you can blow air from the motor side into the tank, the check valve doesn’t work, or more likely, there’s not one there.

Click to expand...

Yes, this is what I found... the check valve was trash.