Gas Spilling/Vent Issue?

[Aunt Bee]

We were able to take the '70 Bee out this weekend to a car cruise-in, along with the Nova. While following each other, we saw gas spill from the the filler tube (under the license plate) on the Bee. It happened twice, both times while accelerating and on a slight up-hill slope. The tank was just about full.

When we filled the tank last weekend (our first fill-up), removing the cap resulted in the cap and air/vapor shooting out under pressure. The vent hole had been plugged with silicone, so we removed the re-engineered 'plug' to allow the vented cap to function.

Our guess now is that someone plugged the vent in the cap to prevent the spills. Is this a common issue, and what is the fix? The gas tank looks to be a new replacement.

We're really happy to have had the Bee out this weekend after a month in the garage. It went straight there from the trailer when we brought it home back in February. New Centerforce clutch, total rebuild on the A833 tranny, replacing the worn-out clutch linkage and some other miscellaneous wrench-turning gave us lots of bonding time with the new toy...so now this gas tank issue will be the next thing to conquer. Any help is appreciated!

 

[70rr-brian]

Had same problem on my 70 RR. Just replaced the filler neck grommet. Life is good again. To test where it is leaking just jack the car up in the front and climb under there. If it has a full tank you should see the leak.

It could well be the vented cap leaking but jacking it up should tell you. What I did long ago on mine....was pull the filler neck out....drill a tiny hole on the top of the neck itself to relieve pressure and used a non vented cap. The postioning of the neck on those cars with a vented cap is a problem waiting to happen IMO.

 

[bigmanjbmopar]

Don't you have vent lines on the tank? You should be able to use a non-vented cap if you do. If not then a vented cap should work. I think the 70 is the same tank as my 69 and should have lines run up into the trunk and back down, I have two vent lines since the car was a 383 original car now that it is a 440 I should use a return line and a vapor canister at the fuel pump like the book shows. I would check out the vent lines first, and with vent lines it is normal to smell gas with a full tank due to expansion. Sloshing out the cap means the seal around the cap is bad did you get a new cap?

 

[Aunt Bee]

Had same problem on my 70 RR. Just replaced the filler neck grommet. Life is good again. To test where it is leaking just jack the car up in the front and climb under there. If it has a full tank you should see the leak.

It could well be the vented cap leaking but jacking it up should tell you. What I did long ago on mine....was pull the filler neck out....drill a tiny hole on the top of the neck itself to relieve pressure and used a non vented cap. The postioning of the neck on those cars with a vented cap is a problem waiting to happen IMO.

Thanks for tips...the filler neck feels 'wobbly', it's not hard to move it side to side, so the grommet may be the problem. We'll investigate more next weekend. That modification to the neck sounds like a good idea, too.

 

[Aunt Bee]

Don't you have vent lines on the tank? You should be able to use a non-vented cap if you do. If not then a vented cap should work. I think the 70 is the same tank as my 69 and should have lines run up into the trunk and back down, I have two vent lines since the car was a 383 original car now that it is a 440 I should use a return line and a vapor canister at the fuel pump like the book shows. I would check out the vent lines first, and with vent lines it is normal to smell gas with a full tank due to expansion. Sloshing out the cap means the seal around the cap is bad did you get a new cap?

...truthfully, we haven't checked for vent lines or replaced the cap yet. This happened on the way home yesterday and we won't have time to work on the car again until next weekend. Great info for us here, though...our '70 was an original 383 car that, like yours, now has a 440. Haven't found a good picture of a tank yet...where does it vent from?

We haven't had a gas smell in the garage since the Bee arrived, so the tank may NOT be vented correctly. That would explain the cap flying when I opened it. When we first had the ProStreet Nova, the gas smell was awful, because the vent tube on the fuel cell was just a shorty. We did the 'plumbing trap' modification to the vent tube and gave it two loops, then lengthened it to exit lower. No problem since.

I checked the tech areas for this topic first and didn't find any applicable info, so I posted for help...and appreciate hearing about the experiences you've both had. We'll let ya' know what we find!

 

[62MAX]

The tank is vented through the 1/4" tube in the sending unit

 

[bigmanjbmopar]

Look at this doc it's right from the 69 service manual

https://docs.google.com/open?id=0B20HDyEEpzYtNkUxUmttY2hRZENfenRMTURkRDhvQQ

 

[Aunt Bee]

Our gas gauge doesn't work (yet), and investigating that wasn't our first priority with the other work the Bee needed. With this venting problem showing up, I'm thinking we'll figure that out along the way, too!

 

[wannadrag]

The tank is vented through the 1/4" tube in the sending unit

[/I]

Isnt that for the return line?

 

[Aunt Bee]

Update, But not fixed yet!

We didn't have a lot of time this weekend, but checked the top of the tank and found that the two vents had one hose connecting them to each other...in other words, the tank wasn't venting. No wonder the vented gas cap, with the vent hole sealed, flew off when I went to open it. Also checked the filler neck grommet, and it's new, like the tank.

So, we decided to run a looped vent tube from one of the two holes, and plugged the other, figuring that would fix our troubles. Not quite.

Took a short drive to the gas station. The fill up resulted in the filler neck popping loose from the tank. Never feels good to have gas spilling out at $4.19 a gallon, and luckily, no one was smoking near by. Pushing the neck back down through the grommet into the tank about 2" stopped the leak, and made us wonder what else should be holding it in place.

Once we got back home, our new looped vent line leaked a small amount of gas out onto the garage floor.

...So much for a prior owner 'restoring' the Bee! :icon_sad: We just keep assuring her that we'll make things right, one by one.

I've now checked on a couple of parts sites to see what we should have, because it's pretty obvious something still isn't correct. We don't have an L-Bracket on our filler neck to mount it. We don't have a foam gasket, either. The only thing holding the filler neck into the tank is the grommet.

Anything else we should be looking for while we're at it? I'll try to get whatever parts we need before next weekend. We'll also try the looped vent line on the other nipple on the tank, instead of the one that siphoned gas out.

And, where is the hole in the trunk located, where the 'roll over' vent tube should come through? We haven't found it yet. Thanks!

 

[Aunt Bee]

Look at this doc it's right from the 69 service manual

https://docs.google.com/open?id=0B20HDyEEpzYtNkUxUmttY2hRZENfenRMTURkRDhvQQ

Couldn't get into the Google documents site...help??

 

[62MAX]

Your filller neck should not come out.there should be a clamp on the neck that attaches to the rear body pan.

 

[Aunt Bee]

Your filller neck should not come out.there should be a clamp on the neck that attaches to the rear body pan.

Yep, that's the piece we're missing! Thanks for the pic.

Just to vent to others who've been through it, our filler neck should not come out, our right rear brake shouldn't be missing the emergency brake components, nor should the emergency brake cable have been jammed into the adjuster's star wheel. Just sayin'...

We plan to own this car for a long time. Some days, it feels like it'll take that long to get it right! We're not purists, but brakes that work and gas tanks that don't leak shouldn't be 'optional'.

Yes, we still love the Bee :love7:, and she's getting better every weekend.

 

[bigmanjbmopar]

try this link it is the complete section on fuel from the service manual. The original section is page 77 which shows the 119.5 " wheel base sedan tank configuration with 2 vent lines one going into the trunk and 90° back down through the floor and the other just turning at the top. This is how my set is and with a NON-Vented cap it works, when I fill up and even top off there is some venting happening when I pull into the garage it is the way the system is designed other wise you have your filler neck shooting out at you :eek




https://docs.google.com/open?id=0B20HDyEEpzYta1hxa2xUVDJUZHFHMnB6el9RT3lIZw

 

[70rr-brian]

AuntBee, just for the record. When I put my new grommet in the tank. The filler neck tube took me 30 mins of hard leaning and rocking to get it to seat all the way in. If yours is coming out easy...that ain't good. Now that I have mine seated....I would imagine getting it back out with a fresh grommet would be all but impossible.

 

[Aunt Bee]

try this link it is the complete section on fuel from the service manual.

Got it that time! Thanks...

 

[Aunt Bee]

AuntBee, just for the record. When I put my new grommet in the tank. The filler neck tube took me 30 mins of hard leaning and rocking to get it to seat all the way in. If yours is coming out easy...that ain't good. Now that I have mine seated....I would imagine getting it back out with a fresh grommet would be all but impossible.

Wow...I'll put a new grommet on that part list! This one doesn't leak, but it certainly is easy to move.