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Old metal tank venting

N

newyota

Regular Contributor
Picked up an old metal 6 gal tank since my one with plastic gauge is cracked. When tank was filled and hose left off and cap put on tank pressure pushed gas out fuel supply nipple. I see the left pin is for the vent since there is hole below it in casting. I blew air in hole and pushed pin in and could hear air pulsing in tank so it is clear. Even with me pushing in the pin manually with cap tight it has gas come out nipple. I assume the pin on right side has worn seal in there and is letting fuel pass?I currently leave hose on when transporting it to keep it from doing this. Am I on the right track?
 
Old OMC 5 / 6 gallon tanks.-----When the cap is tight and the hose is not connected the tank is sealed.----When you connect the hose you push in those 2 wee pins.-----One is a valve that lets gas out.----Other one is a valve that lets air in as fuel is pumped out.
 
racerone said:
Old OMC 5 / 6 gallon tanks.-----When the cap is tight and the hose is not connected the tank is sealed.----When you connect the hose you push in those 2 wee pins.-----One is a valve that lets gas out.----Other one is a valve that lets air in as fuel is pumped out.
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Thanks Racer.Sounds like I need some parts for the fuel pin.
 
You need the two o-rings, and the two core plugs. Also the tiny "wee" o-ring. Be aware that there were two sizes of "wee" used in different years. You do not need to remove the tank housing to do the repair.
 
fdrgator said:
You need the two o-rings, and the two core plugs. Also the tiny "wee" o-ring. Be aware that there were two sizes of "wee" used in different years. You do not need to remove the tank housing to do the repair.
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thanks again..So that should stop the gas from coming out fuel nipple?I do not think it is coing out around the casting where the nipple comes out,but do not think it could any way.
 
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The two pins seat against the two o-rings when the hose is disconnected. That shuts off the vent and fuel. The wee o-ring prevents leakage around the fuel pin stem. It makes no sense to take it apart without replacing all three o-rings.
 
fdrgator said:
The two pins seat against the two o-rings when the hose is disconnected. That shuts off the vent and fuel. The wee o-ring prevents leakage around the fuel pin stem. It makes no sense to take it apart without replacing all three o-rings.
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Thanks. I understand and it would be good idea to rebuild both but will that stop fuel from coming out the fuel nipple if I leave hose off and cap is tight?saw a video where a guy replaced all orings due to gas coming out around Pin but not the fuel nipple.
 
These tanks are the best there is in my opinion.------So do as suggested and replace the 3 little O-rings in there !!---Then report what the status of leakage is.
 
newyota said:
Thanks. I understand and it would be good idea to rebuild both but will that stop fuel from coming out the fuel nipple if I leave hose off and cap is tight?saw a video where a guy replaced all orings due to gas coming out around Pin but not the fuel nipple.
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How many ways can we explain such a simple thing? There is a large tapered area on the pin. When the pin is NOT pushed in, a spring pushes that tapered pin up against an o-ring. Just like putting a cork in a bottle. Nothing can flow in or out of the bottle because the cork is in the way. Now, PUSH THE PIN IN and you are pushing the cork out of the bottle and the juice can flow through the opening. The fuel nipple is the bottle and the pin is the cork. So YES letting the spring push the pin OUT corks up the fuel nipple and stops the flow, while pushing the pin IN lets the fuel flow.
 
racerone said:
There are 2 o-rings inside.-----And one wee o-ring where the fuel pin comes out of the housing.
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I was getting ready to order parts and see the two part numbers for the quad ring,even though it only shows one in picture,assume since you said it is where pin comes out of housing.the wee one sits on top of the larger one before putting on the brass retainer.Still using tank so didn’t pull it part before ordering.
 
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Is the parts list you are looking at the correct one for the tank you are working on? They made that style tank for many years, with slight modifications along the way. As I said, I know of two sizes of the small o-ring. Try to figure out how old your tank is and go from there. Honestly, I've never yet changed out one of the quad-ring types----yet. Have to assume that is a newer vintage (????)
 
fdrgator said:
Is the parts list you are looking at the correct one for the tank you are working on? They made that style tank for many years, with slight modifications along the way. As I said, I know of two sizes of the small o-ring. Try to figure out how old your tank is and go from there. Honestly, I've never yet changed out one of the quad-ring types----yet. Have to assume that is a newer vintage (????)
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Thanks..I may just have to take it apart to verify what is in there.
 
fdrgator said:
The two pins seat against the two o-rings when the hose is disconnected. That shuts off the vent and fuel. The wee o-ring prevents leakage around the fuel pin stem. It makes no sense to take it apart without replacing all three o-rings.
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Thanks for your info on this and Racer also.Hopefully this thread will explain everything to anyone else simple as it may seem.I was surprised that these could still be fixed and now my problem is solved.Posting picture of fuel side I took part first and the valve o-ring was of course the problem.The wee- o-ring was not the type with the double ridge which surprised me.Semed like there would have been room for the thicker Quad o-ring.tank parts.jpg
 
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