Mustang Gas Tank Question???
 

Hello,

I am finishing up the install of the 70 tank in my 52F1, reading through the posts today while it is raining, came across the thread on venting. I used the 70 Mustang tank and the marine type filler. As far as I can tell there is no vent to this system. Do I need to have a vent? What has everyone done when installing their tanks?
I have not yet put any gas in the tank but it should be later today or tomorrow after work.
Please let me know on the vent.

A Big Thank you to all who served on this Memorial Day.

Yes, you need a vent. If the tank is not vented, a vacuum and no fuel flow will result. My Bronco tank had a vent tube that tied back into the filler neck, which I retained when I transplanted it into my 56. If the Mustang tank didn't have a separate vent tube, then the cap was vented. You'll need to vent the tank the same way, with a vented cap or rig up a tube out of the filler neck.

thanks for the quick reply. I was afraid of this after reading the other thread. I do not think the tank or the cap is vented. My idea is to maybe put a small hole into the side of the tank near the top, maybe 1/8" or so, would this be enough to vent it?

Thanks again.

I think that will just give you a leak. How about just soldering a 1/4" dia piece of tube into the filler neck (at right angle) then run a flex tube out to a higher point under the bed?

If you are using the Mustang gas cap and sending unit, why not use a compatible vented cap? Many if not all gas caps used in Fords in the 1960's including some locking caps are vented. Finding a vented cap for the Mustang tank is as easy as asking for one at a parts store.


DO NOT DRILL A HOLE IN A GAS TANK TO VENT IT...A SEVERE FIRE HAZARD WILL RESULT FROM ESCAPING GAS FUMES. IF THE TRUCK IS PARKED IN A GARAGE WITH A HOT WATER HEATER NEARBY, GUESS WHAT WILL HAPPEN?


GASOLINE FUMES ARE MORE DANGEROUS THAN LIQUID GASOLINE.

Well, I went out in the rain and slowly opened the filler cap, the tank was empty but you could hear that a vacuum had developed. I then tried to put in a gallon of gas into the tank, it quickly filled up the filler neck and dripped out on the ground. So I know I have a problem and will need to address this. I imagine I will remove the filler neck and try to install some type of vent line. I can't use a mustang gas cap as I using the marine style filler that screws in. I thought I was getting close to using the truck but now will need to take care of this first.

Thanks for the replies.

Does your gas neck have threads around the opening? Big Ford trucks from the 1950's-70's gas tanks have vented brass caps that screw on, and also use a device on a chain, that when dropped into the tank, prevents the gas cap from accidently being lost.

yes that sounds like the filler neck I have used for this.

Dennis, I have the same ( cool cap ) and the same tank as you do and I just installed a 1/4" brass bung into the rubber hose that connects the tank pipe to the filler neck. It faces to the front, has a 3 foot long rubber gas hose that loops around and then the end of the hose faces to the rear of the truck away from any heat and will not collect dirt ,dust or water. I just put in a new oak floor with 5 coats and wanted to be fine and no problems. I drove 90 miles yesterday with a full tank, hit the 95 mph mark and had absolutely no issues at all. You must use a gas and solvent resistant adhesive for the bung or pipe into the rubber and let it dry, but I also looped the bung with some S/S safety wire and then looped it to the neck. I think it worked fine. Jon

dennis, any pics of the install of the gas tank?

posted some pictures, working on adding a vent line to the fuel filler pipe. I wish I remember where my flux and solder were!

Ford trucks 1973/79 have a vent pipe that is part of the fill pipe (the entire pipe is galvanized steel) on the auxillary fuel tanks (tanks are filled thru the bed sides, the actual tank in under the bed, inside the frame rail). It's about an inch or two down from the opening. You could cut down one of those necks and then use a piece of neoprene gas hose to connect it to the Mustang tank. A piece of neoprene vent hose clamps to the vent pipe. The vent hose could then be routed anywhere you wish.


There are different curvatures on the dozen or so different fill pipes used 1973/79.

I am also using a marine style filler neck. Its not a Cool Cap version as I didn't want the Cool Cap lettering cast into the piece (If I'm going to be advertising for the company I want a huge discount on the part...lol) I actually bought mine at a marina on one of my lake trips.

My Blazer tank has a 5/8" line that runs parallel to the fill tube and connects to the original filler neck. I drilled and tapped my marine style filler neck and added the connection. I think this is just an overfill hose and allows you to fill the tank without it spitting it back at you. I also have a vent line from my fuel sending unit that just attaches under the bed.

Bobby

better late than never...

Quinn Bergmann was nice enough to copy me on his pictures of a tank vent he installed in his mustang tank... AND a solution to the filler neck connection between the tank and the deck filler.... he gave me permission to add it to my Mustang Tank article... sooooo

here it is

mustang tank article update


thanks Quinn

later
John

That the way to go John. The guy did a nice job and good homework.

Jon