Gas Smell/ Tank vent ??

[jweb]

On my '51 every time I fill it up with gas it smells really strong. I was thinking about adding some type of vent.

Will it help? If so any suggestions of what to use and where to run it?

Any other ideas besides moving the tank, I really don't have space under the truck for that.

[my56chevytruck]

Originally Posted by jweb

On my '51 every time I fill it up with gas it smells really strong. I was thinking about adding some type of vent.

Will it help? If so any suggestions of what to use and where to run it?

Any other ideas besides moving the tank, I really don't have space under the truck for that.

Venting the gas tank is for the ease of filling the tank to relieve the air as you are adding the gas. but it would help for the smell issue. I assume the tank is behind your seat?? the only thing I can come up with is to remove the tank, dump the gas, and add a vent line to the filler tube. This will allow you to fill the tank and the air will will escape thru your vent line.

[jweb]

It is behind the seat. The stock filler neck has a vent for filling. I've never had an issue with that.

My stock sending unit isn't being used since my LS swap. So I wondered if I could use that line to add a vent or a charcoal canister. Maybe I just need to reseal it.

[vintovka]

I moved my tank to under the bed. Having the tank in the cab was never a good idea. If you look at gasoline toxicity you might be amazed. I checked my cab back when the tank was still in it with a hydrocarbon detector that read down to 1 PPM. Even when you can't smell it, It was still present in a closed up cab.

[jweb]

Originally Posted by vintovka

I moved my tank to under the bed. Having the tank in the cab was never a good idea. If you look at gasoline toxicity you might be amazed. I checked my cab back when the tank was still in it with a hydrocarbon detector that read down to 1 PPM. Even when you can't smell it, It was still present in a closed up cab.

I wish I would have done that years ago but never liked the idea of a bed filler. I use my truck to haul all kinds of stuff. I would do a '48 style tank that fills through the bedside but it would never fit with my trailing arm suspension. Also would have to weld the original filler hole and try to match the paint.

So I'm just trying to find some creative idea. Maybe I'll just build a box around it and try to seal it really well. That probably won't do much good.

[vintovka]

Bed fillers seem a PITA so I used a 25 gallon suburban tank and ran the filler to the drivers side fender. The old pic shows the cap location . The bed off shows the replacement tank in position but the filler hose is just laying on the fram. The 85 Sub tanks run about 60 shipped and the sender in another 30.

[mr48chev]

If you use the original pickup tube on the sender as a vent you have pull the sender out and cut the pickup tube off or you just created a possible siphon hose setup. Running the canister and venting to it does let you install a non vented cap to cut down on the fumes escaping there while venting the tank so you don't create a vacuum in the tank while driving.. Actually you vent the tank so it allows air in to replace the gas that you pumped out otherwise you create a vacuum and it can and will suck the sides of the tank in before the engine quits in some cases.

Personally I am not a fan of tanks behind the seat even though over the years I've had a lot of trucks with seat tanks. You always run the chance of a leak or fumes plus you lose the space.

On a truck that I didn't want to disturb nice paint or what not I think I'd just invest in a simple locking gas cap, put it on the filler neck in the cab and stick the keys in my hide my extra keys box and call it good. A guy could cut he filler neck off short and cap it and put it back too but some may not want to risk the painted area around it by disturbing it.

I don't like the filler in the floor of the bed either. It's that way on my truck now is a real pain as even though I don't plan on hauling anything except travel gear in the back moving stuff to get to the gas filer isn't something I want to do an I plan on some serious and long road trips with it when it is done.

[dsraven]

if you consistently smell gas after a fill you should check for a leak in the system. especially if you have an old tank with a possible rusty bottom or leaky hose connection. I am not a fan of the seat tanks either, for the hydrocarbon reason, the sitting on a gas can reason and also for space. I have seen some guys' mods that place the tank under the truck and the filler inside the wheel well. a bit of a pain but do-able. also some guys have put the filler behind the lic plate or above the hitch. that usually means a lower tank though. how about an under bed tank with a filler behind a tail light. use muffler pipe to connect the dots from the filler, sourced from a wreck, to the tank. get a tank with a vent and grab the carbon canister as well.

[jweb]

Originally Posted by vintovka

Bed fillers seem a PITA so I used a 25 gallon suburban tank and ran the filler to the drivers side fender. The old pic shows the cap location . The bed off shows the replacement tank in position but the filler hose is just laying on the frame. The 85 Sub tanks run about 60 shipped and the sender in another 30.

That's a pretty good setup. I'm not sure how that fill location would work with a low truck. Also, any tank under the truck I would probably have to change my exhaust. Then there's the fuel pump, fuel line and return line which can get expensive.

[vintovka]

Was thinking about the whole idea of in cab gas tanks. This is a design which requires drivers to drive around with 20 gallons or so of highly flammable liquid which is also a known carcinogen. Uhh hello?

[jweb]

Originally Posted by vintovka

Was thinking about the whole idea of in cab gas tanks. This is a design which requires drivers to drive around with 20 gallons or so of highly flammable liquid which is also a known carcinogen. Uhh hello?

I agree, it's an odd design. Who knows what they were thinking back then.

I'm going to get under the truck and see if there's any way I can fit a tank without changing the exhaust. If the tank will fit over the exhaust, I will add some kind of heat shield and maybe wrap the pipes in that area. Then I can do what mr48 said and just leave the old filler and add a locking cap to it for now.

I'm on my third engine and third exhaust setup, maybe it's time for a third fuel tank.

[vintovka]

I thought about adding one of those combination toolboxes/tanks to bed, Yes it takes up space but so does carrying a spare. No easy fix. There are many things that we used to think were safe.
If you like the smell of gas read this:

https://www.cancer.org/cancer/cancer...s/benzene.html

[joedoh]

check your filler tube gasket, I tried to search for it but someone else mentioned this a couple years ago (it might have even been another forum is why I cant find it) and it was mentioned to change the filler tube gasket, it was made of a different rubber and even a single drop running off the edge of the filler would wick right through to the inside between the tube and the gasket.

[jweb]

Originally Posted by joedoh

check your filler tube gasket, I tried to search for it but someone else mentioned this a couple years ago (it might have even been another forum is why I cant find it) and it was mentioned to change the filler tube gasket, it was made of a different rubber and even a single drop running off the edge of the filler would wick right through to the inside between the tube and the gasket.

The filler neck, hoses, neck grommet and gas cap are just a few years old. I've had the sending unit out a few times so that gasket may be damaged. Not sure where to get a replacement.

[joedoh]

well, thats what i was saying, the new replacements were made of a rubber that werent gas and oil impervious. it was the grommet on the body, but maybe the filler neck too?

the sender gasket is a good idea too

[dsraven]

so, when and for how long does it smell like gas after a fill up? you fill, drive away and it smells like gas for a short time but before you get home it has stopped smelling? you fill and it smells like gas till it get down to 3/4 tank (or whatever) before it stops smelling like gas? it smells like gas all the time? it smells like gas at 1/2 a tank if you go around a corner hard and the fuel sloshes in the tank? it smells like gas on a hot day but not a cold day? the reason I ask is because sometimes the straps that secure the tank or possibly the contact area under the tank can hold dampness and cause a pinhole. for all the time it takes to remove the tank it may be a good idea to yank it out and check everywhere for a gas leak trail. when I got my 57 it smelled like gas really bad because the tank had a pinhole in the bottom where it contacts the floor seating area. the farmer would just put enough gas in it for the purpose he had at the time. the rest would slowly leak out onto the cab floor and evaporate. probably kept the mice out. he wasn't worried about it. the cab had to be pressure washed to get the stink out. I was dismantling the truck anyway so it was coming apart.yours is maybe not gonna get that treatment.

[jweb]

Originally Posted by dsraven

so, when and for how long does it smell like gas after a fill up? you fill, drive away and it smells like gas for a short time but before you get home it has stopped smelling? you fill and it smells like gas till it get down to 3/4 tank (or whatever) before it stops smelling like gas? it smells like gas all the time? it smells like gas at 1/2 a tank if you go around a corner hard and the fuel sloshes in the tank? it smells like gas on a hot day but not a cold day? the reason I ask is because sometimes the straps that secure the tank or possibly the contact area under the tank can hold dampness and cause a pinhole. for all the time it takes to remove the tank it may be a good idea to yank it out and check everywhere for a gas leak trail. when I got my 57 it smelled like gas really bad because the tank had a pinhole in the bottom where it contacts the floor seating area. the farmer would just put enough gas in it for the purpose he had at the time. the rest would slowly leak out onto the cab floor and evaporate. probably kept the mice out. he wasn't worried about it. the cab had to be pressure washed to get the stink out. I was dismantling the truck anyway so it was coming apart.yours is maybe not gonna get that treatment.

I would say it smells really strong until 3/4 tank. I had the tank out last year when I did the LS swap. Replaced the cap, filler tube, grommet and hoses then.

I think I will check for room under the truck. If there's no room, I will try the sending unit gasket and check the plug I have in the stock pick up tube.

[mongocanfly]

Where I work we have hand held vapor detectors..if you could find someone that has one you could find out real fast where the fumes are coming from..a fire dept may have one..

[vintovka]

Originally Posted by mongocanfly

Where I work we have hand held vapor detectors..if you could find someone that has one you could find out real fast where the fumes ar coming from..a fire dept may have one..

Good idea, And what i have done. Bottom line is gas fumes still wind up in the cab as components penetrate rubber and other materials. No vehicle manufacturer today would EVER put a gas tank in an enclosed passenger area. The way the big C is taking folks makes you think about reducing your exposure where ever possible including during fill ups.

[nvrdone]

when I still had an in cab tank, I had the same gas smell. plus when I filled the tank, it all ways spilled over & ran down the side of the cab. On the filler neck there is a small hose for a vent. I put a "t" fitting into that & ran a hose thru the floor into a charcoal canister mounted on the frame rail. didn't have any more gas smell after that.

[jweb]

Originally Posted by mongocanfly

Where I work we have hand held vapor detectors..if you could find someone that has one you could find out real fast where the fumes are coming from..a fire dept may have one..

I wonder if this works
http://www.ebay.com/itm/Combustible-...-/111961052522

[Stepside Jim]

I'm not sure of the sending unit mounting, but, something to consider.

My '57 uses like 5 or 6 screws that hold the sending unit in place. These screws use lock washers also.

I had the odor issue also, someday perhaps I will move mine to the back, but I have what I have right now.

What I found is the sending unit mounting screws thread into the tank, there is no sealing qualities between the tank threads and the screws, not like a male to female pipe thread would give.

The gasket doesn't seal perfectly to the screw threads either.

The lock washer does not provide a perfect seal either, is has a split in it.

My theory is, no matter how tight you tighten the screws, vapors can still follow the threads up to the screw head and into the cab from there.

I ended up coating the sending unit screws and the threads in the tank with ARP thread sealant. Now the vapors can't work their way up the screw threads and into the cab.

Now I will occasionally get a whiff of an odor, but that could be the cap just behind the drivers door venting occasionally.

Good luck, Jim

[mongocanfly]

Jweb..that should work great..ours are more industrial but are very similar to that

[dsraven]

if it smells until 3/4 tank then the issue would likely be in the top 1/4. sounds like you got it covered as far as what to look for.let us know what you find.

[dsraven]

if you live close to a fire station you could stop in and ask them if they have a monitor. they would likely be all over it. they like old iron too, mostly.