The Stovebolt Site Forums The Shop Area Engine Shop Gas tank filler tube and vent.

Gentlemen, The attached photo shows my gas tank. The tank is mounted under the bed of my '65 C10. This is the way I got the truck from the previous owner. As may easily be seen, the filler tube and the vent are hardly ideally configured. My particular question right now concerns the vent. It will be observed that a length of hose is attached to a nipple on the tank and then the hose is simply left to dangle or otherwise "hang around." (I am supposing that the purpose of this hose is to permit air in the tank to escape as one refills the tank with gas.) As well, it will be observed that there is a valve in the end of the hose, some kind of pcv or other 'check' valve, apparently put there with the intention that gas not spill out.

I am relatively new to this truck and I am not a mechanic. But I am looking at all this and sensing that some change is needed. For one thing, it seems to me that if there is to be any valve on this hose, such a valve should sit on the tank nipple, i.e., be between the tank and the hose. Secondly, it seems to me that the free end of the hose should have some kind of filter on it to prevent dust from making its way up the hose and into the tank. Thirdly, it seems to me that the hose should then be tied in place at a point that would not permit leaking gas to drip onto the exhaust. I cannot find any thread in the forums that delves into this issue. I therefore ask that someone stop me from doing the following if I am about to do something bad.

I want to buy a filler neck that will have a nipple on the neck such that I can connect the vent hose to it. I will then mount the filler neck to the inside wall of the bed. I will remove the juryrigged filler elbow presently in place and replace it with a good diameter rubber gas hose and try to avoid such a sharp turn as created by the steel elbow.

Does any of the above sound zany to you guys? Right now I have a problem whenever I fill gas. I have to fill gas very slowly because (I believe) that elbow is causing an air lock when filling gas and the gas backs up and spills out onto the bed and pavement. Any ideas or comments would be appreciated. -Alden

https://plus.google.com/photos/117346175748082124087/albums/6042345673177252273

Allen, your ideas sound right on the money to me.

Your tank looks very similar to the '49-'52 Chevy passenger car gas tank I am using in my '65 C10.

The problem with any type of valve in the vent line is it restricts the flow of air/gas vapors in the vent line. I suspect that is part of your slow filling problem.

I used a "sintered bronze vent fitting" (google it) on the end of the hose on the vent on my truck. I did this to prevent dirt and bugs from getting into the gas tank. I attached the vent to the vent hose on the top of the tank away from the exhaust. vent fitting The fitting was purchased at a tractor supply store and it's intended use is as a vent on a hydraulic fluid storage tank (to vent petrochemical vapors).

Your idea of using a filler neck with a vent fitting is a good one, but I doubt you will find one with a 1/2" vent port unless you make one for yourself. My only regret on my installation is that I didn't do this very thing. Mine fills slower than I would like.

More info here: Rear mount gas tank

Hope that helps

John

Alden
I too think you are on the right track. I want to mention that as I look at the photo you posted, I don't think that the "filler" hose that you currently have is a true filler neck hose. It looks to me to be a radiator hose. If this is the case it is bad. As this hose starts to fail it will do so from the inside out. Thus dumping dissolved rubber bits into your tank and then to your carb. True gas tank filler hose is not very pliable, it can bend but it isn't made to make a 90 degree bend. I am more of a "stock" kind of guy but I believe that the Rod shops will have what you are looking for to do this correctly.

Brian, John, thank you for your responses. When I read Brian's comment about that hose I picked myself up and went right away to check. There are no markings on the hose. It does, indeed, feel somewhat soft and pliable. I am going to assume it is radiator hose. I will pull that off my truck tomorrow. I can only pray that my fuel filter caught any dissolved rubber. I should probably take the filter out and have a look. Anyway, I did run out of gas the other day (had a bad ground on sending unit) and I somehow recollect my dad saying that any time you run out of gas, you need to change the fuel filter. I don't know of any 'rod shops' near me, but I do have a few auto parts stores and I will try to find something if even it be temporary.

John, I am also not sure where I will find a filler neck with such a nipple, be it 1/2" or otherwise. I sort of assumed all filler necks would have this nipple. If I do not find a neck with nipple, I will just have to do much as you did. Is it your opinion that the nipple needs to accept a minimum 1/2" i.d. hose?
I do not think it should be too difficult to fabricate a proper fill neck. I am a lousy welder, but I could probably attach a nipple using JB Weld, no?

-Alden

Too much vibration, stress, volatile vapors for JB weld in my humble opinion. Time to learn how to weld so we can check off another box on your man card. Trust me, when you become even a little bit skilled at welding, it is very liberating. You will feel like MacGyver.
Carl

Filler Hose: Best new product. Awarded by: National Street Rod Association.

Filler Neck: I'd agree with Carl, stay away from JB Weld. I am sure you can find a local fab. shop, muffler shop, radiator shop or hobbiest that would TIG or MIG weld a bung to a filler cap for you. Or set out looking for a cap with a vent: filler caps with vent lines

Filler Cap Vent Line Size: size it so it is the same size as the vent line.

John

I did not read all the long responses...sorry. Currently, that photo indicates an "open" system. In other words, the fuel vapors are free to escape (assuming valve is positioned to allow free escape of air/vapors for filing purposes). If the valve is working, then it allows vapors out and not in (along with dust).

This is not good for safety and the environment in my opinion. If you park in an enclosed garage, you can lose fuel vapors that can collect and ignite unexpectedly. This needs to be fixed.

The vent line is supposed to connect back to the filler neck ABOVE where the end of nozzle would be inserted.

DavidF, Thank you. I have made a good mental note of your point.

Carl, you are certainly right about it being time to practice my welding. I will pick up a little welder to learn on and do small jobs.

John, I find plenty of the correct stuff online. I will hop on over to the auto parts store first and then, if need be, order online.

In the meantime, I removed the hose shown in the photo -the hose with the 90 d. turn. It has markings that I did not see previously. They are: YCC MADE IN USA 2034. {Note that the marking "YCC" appears close to the cut end of the hose, so I cannot know whether there were any letters before the 'Y'.} Whether good or not, it is not the configuration I want, so it is staying off. -Alden

Brian, guys,
Well, the auto parts store has nothing of use to me on this little project. Went online and wow, hose rated for gasoline is not cheap. Looks like $2 per inch. I know I don't need much. Anyway, the nipple on my underbed tank is 1 3/8" o.d. (Spent more time looking for my reading glasses than measuring anything. Every time I use a ruler, the numbers are harder and harder to read.) Spoke to the guy online, he says they have 1 1/4" i.d. hose that should yield to go over my tank's nipple without any problem. I guess I will take about a 6" length of that hose. Now I have to find a filler neck w/vent nipple that will plug into the other end of the 1 1/4" i.d. hose. Found plenty of filler necks online, but none state the o.d. of the neck's pipe. I suppose I just have to get on the phone to them. If anyone knows of a particular filler neck (with vent nipple) that will plug into a 1 1/4" i.d. hose let me know. -Alden

When I needed a filler I found one by searching Ebay for the right size and configuration. If it's too long, cut it short, just so the rest is what you want. DavidF's comment about where vent should be is important. If you look at a 55-59 filler you will see an example. One of those (used) may be an option. You do need to get the same size hose that fits the tank inlet. Don't forget marine/boat supply places have good hose, even Bass Pro, Cabelas, etc. I missed what vehicle and year this is for? There are several opinions/reasons for a vent. Air has to escape when filling tank, air has to come in to prevent a vacuum, gas/tank gets hot and expands causing burping. As also said, when you fill it's big volume coming in, if air vent is small, can't keep up and burps out someplace. Some folks run a vent into a modern charcoal filter canister. When you see the sign at the pump "Do Not Over Fill", it helps to adhere to that or you can block the vent or fill the canister on some vehicles. If an unvented/malfunctioning cap is used in some systems it will cause gas to spill out for a long time in the garage. Some will drill a small hole in the cap to prevent this.

I've replaced the hose joints on a couple trucks, checked a leftover piece of approved gas hose I got at NAPA for the TF trucks, right at 1.5" ID, and yes it is spendy .... you will not get a 1&1/4" hose over a 1&3/8 tube if it's the correct gas approved hose, there is virtually no flex or give in the stuff, it's a struggle getting the correct size on

Bill

Bartamos, thank you for your attention. I did not like what I saw with my tank from the very beginning. It surprises me that the previous owner, an individual who told me that he used to work in the engineering and design department at GM, would install his gas tank in such fashion. I have already taken the mess out of my truck and will be installing a filler neck with a vent in the proper fashion. I will not be adding on any carbon canister at this time, though I intend on reading up on its merits when I get a chance. My tank's fill inlet is near the top of the tank, on the side, angled upwards at about 45d. Very close to it is a steel beam that goes the length of the truck and which I hesitate to notch even minimally. I will, for now, have my filler neck sort of standing up in the middle of the bed. I will live with that until I can weld up some plumbing and pipe it out to the side, under the bed. That will have to wait for an opportunity when I can drop the tank, empty and clean it, and put in an inlet that is slightly lower and without angling upwards. Not a quicky project, but nothing daunting. What got me off of my butt about it now is that Brian and the guys edified me about the risks I was running with what I had. Thank you all for the help. -Alden

Red58, Hmmmm. I measured my tank's inlet with a caliper. It is 1 1/4" i.d. and 1 3/8" o.d. When I spoke to the guy, we were discussing an item that is for gas filling and he said that it should go over my inlet. But I imagine he has never done it himself. I understand from you that it will not happen. Are you suggesting that I go with a filler hose that is 1 1/2" i.d.? That is going to mean that I have 1/8" to close up with a hose clamp. If gas hoses are as stiff as I am given to understand, I wonder about the sufficiency of the seal that I will get. I have not found gas hoses with i.d. of 1 3/8" for a more precise fit. Maybe they have escaped my online searches. I will search again. Otherwise, I will have to get the vendor of the 1 1/4" i.d. hose to agree to take it back if I cannot get it onto my 1 3/8" o.d. inlet. He seemed so confident that it would not be problem.

I am wondering about an alternative method: Maybe go with steel or aluminum pipe that is 1 1/4" o.d., grind off a few thou from its o.d., insert it into my tank's inlet, and then use hose with hose clamps to seal that. If that was clear, what do you think?

The tank I have seems to be the tank that many have installed under their beds. It may be that the manufacturer intended all plumbing to be welded. I know I have seen plenty of radiator hoses being used for these connections. Apparently, it is hard to find the gas hoses with the needed size. -Alden

I'll have to double check if I can find the fill necks I know are in the pile somewhere [and a caliper instead of a carpenters tape ], but the stiffness of that type hose is why it's only used for gas lines, don't think the 1.5 would clamp down to 1&3/8, but it might - if I were to use metal I'd want to use steel and weld it, a muffler shop could bend up whatever you need and they have a range of adapter couplings, could step up or down

Bill

Red58, yes, I know a muffler shop could do whatever I need. I am trying to avoid that expense at the moment. For now, I want to just get a proper connection and I will suffer it standing up in my bed. Once I get a chance, I will drop the tank, weld shut the current, upward angled inlet and do a new one, with horizontal inlet, that will permit routing the plumbing under the bed and to the side of the truck. These tanks, what with being hung right up to the underside of the bed, with the inlet at the top edge and angled upward, cannot be plumbed in any style that suits my preference. At the same time, I can enlarge the venting nipple from 1/2" to 3/4" which should allow quicker fill-ups.

I have to double check in the morning whether my tank is steel or aluminum. I think alum is hard to weld. Brazing might be called for.

Ach. Until you guys spoke up, I thought I would just get some radiator hose and JB Weld and be done with it in an hour and for less than the cost of a pizza, lol.
-Alden

UPDATE: For the hose I just ordered Goodyear Part No. 59215. Their website indicates this to be a gas filler hose, SAE J30R6, with an i.d. of 1.4". I should not have to muscle this hose onto the inlet: if I am correct, the inlet is 55/40" o.d. and the hose is 56/40" i.d. I only need to hope that a hose clamp will close up the 1/40". (Actually, the Goodyear website says the hose is 1 3/8", but when ordering it on Amazon, the i.d. was said to be 1.4".) Also, the website says the part is 36" long, but when ordering from Amazon, the part is said to be 18.8" long. This does not matter to me. At $25, delivered in 48 hours, I think I did ok. The best pricing I found otherwise was $2 per inch, plus shipping. Now to find a filler neck.... -Alden

mic-ed the hose I have, and it is 1.5", couldn't find the pickup fill neck right off, but I did find a TF panel truck fill neck and it's 1.25", checked a panel tank outlet too, 1.25" .... doubt you'll find a panel fill neck, but there might be others the same size

Bill

You measured 1.375 and the hose is 1.400= delta .025 or .0125 per side to squeeze, sounds perfect to me. Use two clamps if you want to. Your 40th of an inch is correct but who measures in 40th's?
If you fix the pressure problem you will fix the leaks.

Red58, thank you for your effort. Since I am not doing any kind of final configuration of the filler set-up, it does not matter to me what style of filler neck I find. My filler neck will be simply, if not primitively, in the middle of my bed and protruding up through the bed. Obviously not convenient and not pretty, but it will have to do for now because I am not able to get materials and do the necessary welding yet for a more cosmetically pleasing arrangement. As such, if your 'TF' filler neck has a 1.25" o.d., it seems to me that it certainly fits into my 1 3/8" i.d. hose. It would then be up to a hose clamp to seal it. The difference of 1/8" remaining between my hose and your neck is, practically speaking, only a 1/16" difference. I think a hose clamp should have no problem with that. Please let me know if you have a photo and an asking price for it.

Bartamos, the reason I converted to fortieths of an inch was to get a more visual comparison of how the two pieces mate. With my math skills, it is easier for me to just find a common denominator. I know it looked funny, but it fell nicely into my head, lol.

Thank you, gentlemen! -Alden

On the Amazon website, some genius decided to round off 1.375 (1 3/8) to 1.4 not realizing it's not just a mop handle , it's an important dimension. 1 3/8 hose ID fits a 1 3/8 tube OD with soap. Did you misstate $2/ft? That's $4 for 2 feet. That is dirt cheap. You are getting a little over 1 1/2 ft. O'Reillys has 1.375
for $24/ft

Bartamos, my Amazon order totaled to $25.68. In general, I saw that hoses rated for gasoline go for about $2 per inch. Yes, I mis-stated that. Oops. Sorry. -Alden

actually the best hose rated for gasoline can go for way more than $2, it's the standard [USCG required] for marine applications, I think mine was by Goodyear or Gates, from NAPA, although it has the marine SAE# [we're a coastal town] .... the pic is for reference, the clean filler is for my project, the dirty one goes with the spare tank from a parts truck, sorry

Bill

I have no idea what the size listed in Amazon means 18.8 x 3.4 x 1.4. As you know, that part number is supposed to be 1.375 ID, 1.750 OD, and 36" long. What kind of people do they have typing the descriptions at Amazon? People from the Amazon? If you get more than 1 foot, it's your birthday!!!

Red58, I ordered Goodyear because I like the brand. I trust them. But I sure was surprised when I started my search for gas hose -I could not believe the prices. Then I thought $2 per inch was the highest. Now you say that it isn't. Wow. Insane. I did come across generic gas hose for $1.50 an inch plus shipping, but by that point I was skeptical of its quality and went with Goodyear. All in all we are talking about filler neck hose on a truck -not the space shuttle! BTW, that filler neck in your photo looks real nice.

Bartamos, yep. It is especially irksome when a part number is described on the site differently than it is on the maker's site.

I am glad I am past this gas hose story now. I always learn something new when I come to the forums here. Again, I thank you guys -and Brian Moore for his sharp eye when looking at the pic I initially posted that showed my truck's gas filler hose to be a radiator hose. -Alden