36 Gas cap venting

[30six]

Bought a new gas cap for my 36 in fall and over winter I misplaced instruction showing size and location to drill vent hole.

Vintique cap.

I looked at old cap and hole location, but it does not have rubber gasket like new one.

Any info before I drill hole?

Thanks!

[blucar]

Rather than drill holes in the new cap to vent it, go purchase a vented cap. A factory vented cap will have a valve inside of the cap that will allow air to be drawn into the tank to prevent a vacuum, release pressure that may build up from heat expansion, and prevent water from leaking into the tank from rain and/or washing the vehicle.

[Don Rogers]

Is your gas tank and filler neck original? If it is, the filler neck is vented and the gas cap doesn't have to be.

[Karl Wescott]

Vintique makes two different caps, one vented, one not. Be sure you have the correct one. My understanding is 1932-1935 used non vented caps, 1936-later used vented caps.

Re Don Rodgers: Was the filler neck vented to outside air or did it just have a bleeder tube to vent the tank while filling. If the latter only then the cap (or tank) will need to be vented to allow air in to displace fuel used, in addition to expansion/contraction from temperature.

[Don Rogers]

Karl, Ford placed a vent tube in the filler neck in 36 after they eliminated the hydostatic sending unit. I thought that they did this to provide venting for the 36 tank.

[Karl Wescott]

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The repop (drake) 40 filler we have on the shelf has a similar vent tube but it goes back inside the tank. It will not vent the tank to outside air, it appears to allow air to excape from the tank while filling, preventing "burping" of gas out the filler opening if the filler tube fills up before draining into the tank.

[Don Rogers]

Karl, The original 36 neck (that I have shown above) vents to the outside and was used with the 36 unvented tank with electric sending unit. Also, if I'm not mistaken the 36 used the same unvented gas cap that was used in prior years from 32 thru 35

[Lawson Cox]

Don is correct. 36 vents to the outside, and used the same unvented cap from at least 34-35. So much for "Just like original" reproductions

[DavidG]

Don,

You might add that the '35-'36 and '37 Ford-released locking gas cap versions were also not vented like the standard gas cap. Both my '36 tank necks are vented to the outside and on my completed car, I use a gennie locking cap without any vacuum lock being created.

Dave

[Terry,OH]

for the 37-40 type filler necks the small tube exits the inside of the filler neck tube and there should be a small hole drilled into the side of the small tube for venting, near the gas cap. Ford had problems with this design and moved the location of the small hole to prevent water from entering and dirt from plugging it.

[Karl Wescott]

Great info guys, thanks for all the input

[Labold]

I'm having the same dilema, just a year later-

I too have an unvented gas cap that I purchased over winter and now need to vent it. Can I drill holes? When I bought the cap I remember it had directions as to where and what size hole to drill. I can remember that, but not where the actual directions are.

[Ed Pitts]

Here are pics of my 36 vent pipe. The cap is not vented.

[Labold]

photo of holes I drilled in the new cap (but still ends up with way too much pressure in the heat). Rubber gasket foiled my simple hole drilling idea.

[30six]

Here is what I received from VINTIQUE

[Labold]

Thanks 30six, those are the directions that I lost. Seems I drilled everywhere but where I was told to. ...I guess 1 more hole won't hurt :-)