Does fuel tank have a check valve?

J

JFoshee

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My fuel line goes in the top of my tank. I can blow through the line toward the tank and it seams plugged. Even with shop air it seams plugged. I can pressurize the tank from the fill cap and some ( a dribble) comes from the line that would connect to the water sep. Is this normal? Is there a check valve in the system for a safety reason? :confused:
 
Don S

Don S

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Re: Does fuel tank have a check valve?

There is one, in a way, it's called an anti siphon valve. Prevents fuel from siphoning out of the tank in case the line breaks lower than the tank.
 
JustJason

JustJason

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Re: Does fuel tank have a check valve?

If your gas tank is above your fuel pump, in overall height, then yes there will be an (or should be an) anti siphon valve (check valve)
If the fuel tank is below your fuel pump, then an anti siphon (check valve) is not required by law, but may still have one in it.

You can only pressurize the tank from the fill cap if you block off the fuel tank vent line. Or pressurize through the vent line and hope the fill cap holds.
 
J

JFoshee

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Re: Does fuel tank have a check valve?

Thanks. Hope to install new fuel pump tomorrow. It should suck the fuel out of the tank I guess?
Side note: Fuel pump for 5.0L mercruiser $130 at marine dealer, $118 at NAPA, $65 at parts house on other side of town( not sure of brand yet, but it's new)
 
J

JFoshee

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Re: Does fuel tank have a check valve?

GREAT INFO!! Thanks. I am 99% sure my old pump is junk. It's pumping no fuel from a jug sitting beside it. I can blow fuel through the seperator by mouth, but add fuel pump in and spin motor... no fuel. I will install new one tomorrow and if I still have trouble I will follow your procedure. Thanks again.
 
JustJason

JustJason

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Re: Does fuel tank have a check valve?

Why not do the test then decide if you should replace the fuel pump?????


A leaking hose barb would cause it not to draw in much if any fuel.
 
Don S

Don S

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Re: Does fuel tank have a check valve?

JFoshee said:
Side note: Fuel pump for 5.0L mercruiser $130 at marine dealer, $118 at NAPA, $65 at parts house on other side of town( not sure of brand yet, but it's new)
Click to expand...

You do understand that you need a MARINE fuel pump, not an automotive pump don't you ??????
 
J

JFoshee

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Re: Does fuel tank have a check valve?

Positive the pump is bad the check valves inside won't hold. I took it apart to look and see. I figured why not it wasen't working anyway.
Don.S> Yes. The auto parts guy pulled out a marine catalogue and looked up my mercruiser engine. It was the exact pump I removed. Thank you for your concern. I am still new to I/O engines and drives and all reply's are appreciated.
 
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