Newbie needs help with gas smell...

[OneHalfMex]

Hey guys,

I have a '69 with the gas tank behind the seat. I like the truck but the gas smell is just about unbearable... If I drive just 5 minutes all of my clothes smell like gas, 30 minutes will give you a headache. I recently realized that I don’t really drive the truck anymore because the smell is so bad.

I searched on the board and all of the suggestions are to get a new gas cap. Well to make a long story short, about 6 months ago the tank started leaking gas into cab and I took it in to get it fixed. The shop rewelded the seam of the tank as a crack had occurred. They told me the crack occurred because my gas cap was not vented… so they drilled a small hole in my gas cap and sent me on my way.

Since then, the truck as really smelled of gas. I am really new to working on cars so I’m gonna need a little help here. What kind of gas cap should I get? It looks like the ones at the auto parts stores are sealed. Will buying one of these could my tank to crack again? Was the shop correct that my cap caused the pressure to build and my tank to crack?

I would love to want to drive the truck again, so any help would be appreciated.

Thanks!

[treveiger]

My truck has a locking gas cap and all it does is pop on. Ive never heard of a sealed gas cap craking a gas tank. Is there a rubber spacer on the fuel sending unit, if theres not there should be and if there is is it bad? The smell maybe because of the old gas that leaked into the cab when it cracked, i would give the truck a good cleaning and see if that helps, and maybe if the rubber on the fuel sending unit is bad replace that too. Theres always the smell of gas in the cab of these trucks and if it really gets to you maybe look into relocating the tank underneath the truck. Ive seen a lot of guys do that and that solves all there problems of the gas smell in the cab. Search it on here an youll find plenty on how to do it. Everything you could want to do to these trucks has been done by someone on this sight lol. Welcome to the forum by the way. I hope you fix your gas problem

[stevencvn72]

Welcome aboard and I've gotta X 2 with the post above. I delt with a leaky (at an understatement) tank. Had to gut the interior. Still have a little smell esp when I "fill" up, the gas tends to seep out around the sending unit seal. It's new, but maybe just not the best quality. I dunno, but it doesn't stop me from rolling in the pick up.

The small hole they drilled for you should work just fine. Did the same thing to a '53 I had some time back with no problems.

[Lee H]

Your going to have to pull the seat out and find out where it's leaking. Could be one of the rubber hoses, sending unit seal, or a leaky tank. There should be no hint of gas at all in the cab. Also make sure the vent tube is open.

[OneHalfMex]

Thanks guys! I'll pull out the seat to check the rubber spacer on the fuel sending unit and to give everything a very stringent cleaning. As far as the gas cap goes, the hole they drilled shouldn't be a problem right? Also, where exactly is the vent tube, and how do I ensure that it is open?

Thanks!

[68gmsee]

Originally Posted by Lee H

Your going to have to pull the seat out and find out where it's leaking. Could be one of the rubber hoses, sending unit seal, or a leaky tank. There should be no hint of gas at all in the cab. Also make sure the vent tube is open.

I agree. My 68 had a bad smell for several years. Not real bad but enough to keep me from driving with windows closed in cooler weather.

This last summer I decided to take a real close look. I removed the seat and found a couple of extremely small pin holes in the bottom of the tank. I didn't mess with trying to seal it or weld it since it was the original tank. I bought a new Spectra gas tank and haven't had even a hint of fuel smell since then.

I got it from Rock Auto but other local vendors sell it. PN is GM49A

[68gmsee]

Originally Posted by OneHalfMex

Thanks guys! I'll pull out the seat to check the rubber spacer on the fuel sending unit and to give everything a very stringent cleaning. As far as the gas cap goes, the hole they drilled shouldn't be a problem right? Also, where exactly is the vent tube, and how do I ensure that it is open?

Thanks!

Yours probably doesn't have a vent tube. I believe they installed them on 72's IIRC.

Re. hole in cap: The cap should have an internal vent that allows the pressure to be released in hot weather. Get a new original cap from NAPA or vendor.

[OneHalfMex]

Thanks 68gm!

[swamp rat]

I agree on the origional replacement cap and the possibility of getting a new tank and sending unit gasket.

But what cured my gas fume problem was simply replacing the short length of rubber hose connecting the tank to the filler neck. after 40 years its rotted.

[Notrodder]

You don't have to put up with the smell of gas in these trucks. All of the trucks of this era that I know of don't have a trace of gas smell in the cabs. A fuel leak in the cab is a health and safety hazard and is absolutley unacceptable.

Finding your leak may be a hassle, but it is necessary. It could be that your repair shop fixed only part of the leaky seam, or , as stated above, the filler neck or sending unit seal could be bad. And a new gas cap (without a hole drilled in it) is in order here.

Good luck with this. I'm sure you'll get past it and enjoy driving your truck again.

[OneHalfMex]

Okay, I did find the cause of the gas smell. The spot the shop welded has developed a pin sized leak. I've decided to replace the tank rather than fix it again. I'm really excited to get the gas smell out of car and since I am spending the money to buy a new tank, I want to make sure I do EVERYTHING I can to make sure the smell is gone.

I ordered a new tank which included a sending unit gasket. Gonna order a new filler neck grommet as mine old is all dried up. Also gonna order a new gas cap. I'm looking at this gas cap:

http://www.classicparts.com/1947-70-...ctinfo/23-155/

Although I can't tell if it is a vented gas cap or not... Anyone know?
Also, are gas tank mounting pads worth buying... only $5

http://www.classicparts.com/1949-72-...ctinfo/23-325/

Swamp Rat, what length of hose are you talking about? My tank is welded to the filler neck and goes straight out of the cab to the gas cap. I'm trying to figure out an other potential problems so I can make sure to get this smell out!

Thanks guys.

[swamp rat]

Humm, Man i'm talking over 15 years ago but i thought i had about a 4" length of filler rubber hose between the tank neck and the filler that leaves thru the cab, But man was i wrong...

As per the cap i would probably call them and ask to be sure, the rubber is cheap..

[wzuke]

My leak was the metal tube gas line that goes through the floor(the fitting was leaking) plus an incorrectly seated gasket on the sending unit plate.