My vent is in the tank's cap.
Fuel Tank Vacuum
- Thread starter bruceatlam
- Start date
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My vent is in the tank's cap.
I do believe you will find that there is preasure in the tank not a vacuum. The carbon canister on gas units vents the tank into the air inlet. Part of the emission tests for a gas unit is the checking of the cap to be sure it holds the proper preasure.
Just a thought!
Just a thought!
OP
bruceatlam
Platinum Member
Thanks --- I see it. I'll check my cap to see if it's the same ---- on my cap, that disk that has the vent hole in it will freely fall out of the cap. Is yours the same?
It's in there tight. I don't see coming out unless the cap was broken in 1/2
OP
bruceatlam
Platinum Member
OK --- I took that disk with the vent out of my cap. It looks like yours definitely has a pin hole in the center of that soft, flexible membrane that's dead center of the disk. Mine has no such pin hole --- it's a solid, soft flexible membrane. Maybe that's my problem ---- picture below without the cap.
OP
bruceatlam
Platinum Member
Lousy pic --- hopefully, this one is better.
When you look into the center of the disk on mine, that light colored gray is a spring.
OP
bruceatlam
Platinum Member
So, there's no pin hole in that membrane?? I could swear that I see a pin hole in that first pic that you posted --- And, I agree --- the light colored gray around the outside edge looks like a spring to me too.
Creamer
Elite Member
Typically the vent is in the cap. If not there is another opening somewhere on the tank but since the cap is on top and there is a already a hole in the tank there, the cap is the easiest place to put it.
Dan Hunter
Platinum Member
Running a vacuum reduces foaming for diesels with return lines from the injector pump to the tank.
