Gas tank vent question.

Richie

From a full tank down to about a quarter of a tank I get a very strong gas smell when making a right turn at 20 mph or faster. Left turns are fine. I got under the car and saw that the vent hose was dripping gas. I wiped the gas away and shook the car side to side very hard and sure enough drops of gas started coming out of the vent hose. I had the tank boiled out and pretty well cleaned and as far as I could tell the little right angle vent looked good, no cracks or anything. When flushing the tank out with water the vent flowed water out easily. My question is should there be something in the vent to stop the gas from leaving the tank? Thanks in advance for any help. This is a 53 7C. Richie.

Edwardjohnsr

Richie:
I've had some issues with my vent and got one from a donor tank. It didn't have anything inside the little cylindrical shell, no baffles or anything else. However, be sure it has the hose connected that goes to the filler tube. Any gas that gets into the vent should either drain back or splash up to the connection on the filler tube. These are just my observations and someone else may have better information. Good luck.
Ed

Park_W

Richie, if you're talking about the short vent pipe at the tank, there's supposed to be a piece of hose connecting that pipe to the vent "riser pipe" that's pargt of the main filler pipe. It runs down along the filler pipe to a point about three inches from the tank vent pipe. With the riser connected to the tank vent pipe, the actual venting now occurs way up high in the filler pipe, only a few inches from the top. So, no loss of fuel, no smell. Be sure to use tubing rated for fuel use.

GrimGreaser

Related issue - mine does the same thing... vent tube is fine, but gas sloshes up out of the fuel cap vent with a full tank when turning right. I just chalked it up to poor filler tube location (bottom of tank, under fuel level), in that when turning right all that gas comes up the filler tube as it sloshes side-to-side. I have a new fuel cap, but it is a vented one. Are they supposed to be non-vented? I've read here that can cause issues when a vacuum is formed in the tank limiting the flow out.

Park_W

You've read correctly, Greaser. Should definitely be vented.

GrimGreaser

Okay, so is gas sloshing out the filler common? The gas tank seems to be the weak point in stepdown design, in my opinion. Fuel sloshing out the filler because the tube is below the fuel level, and the pickup in the front of the tank leaves you SOL if you're low on gas and have to get up a hill. Anyway, just bitching 'cause I was on vapors, and the cheaper (by $0.10) station was uphill and I could not get up there.

Richie

Ed, Park and GrimGreaser, thanks you all for your info. I am going to attach a pic of my tank as I was taking it off the car. I don't see anywhere to attach the vent hose to the filler neck. Can I drill a hole somewhere in the filler neck and screw in a fitting and just run the vent hose up to it?

Park_W

Richie, it's hard to see the filler neck very well. But it sounds like that filler pipe has been modified. You should have a 3/8" or thereabouts tube running down the side of the filler neck. If nothing there, you could find an appropriate fitting or have a shop solder a piece of tubing (of the right diameter) into the filler neck a couple inches below the top.

TwinH

My tanks out too (49). Heres a couple pics of the vent tube in the filler neck.

Richie

Park, there is no tubing running along side, I didn't see any hole where tubing might have been attached. I'll check more closely tomorrow. Thanks Park. Richie.

TwinH, mine definately doesn't look anything like your tank, thanks for the pics. I'll have to fashion something that resembles your tank setup TwinH. Your pics helped me, thanks very much. Richie.

[Deleted User]

The gas tank has to be installed then the neoprene gas line installed. it sits above the frame cross member. Somebody soldered the openings to make the tank go in easier, and screwed it up. Walt.

Richie

Thanks Walt, I'll be working on it this afternoon. Richie.

Richie

Gas smell is gone !! I thank all of you for your comments and help,the pics saved me lots of time. There was no tubing where there should have been but there was about a 3/8'' hole in the filler pipe right where it was supposed to be. I threaded it with a 1/8'' pipe tap, screwed in a right angle brass fitting aimed downward. I used some 5/16'' steel tubing to go from the fitting and ran it down thru the floor next to the filler pipe and attached the vent hose to that tubing above the frame. I'll re-seal that area in the trunk floor again.
Again, thanks guys I appreciate your help. Richie.