Right now I've got a standard locking gas cap on my cab tank, the kind that just presses in and locks. The problem I'm having, is it doesn't seal. So when I've got anything over 3/4 tank of gas, it leaks out going around corners.

Since gas doesn't do much good for paint, I'd like to fix the problem.

So far all the locking caps that I've found are the same as mine. So, does anyone know of a quarter twist gas cap that locks?


Thanks
Jameson

 

There was no 'standard' fuel cap, because...

In-cab fuel tank: There were TWO different fuel caps.

(1) With Evaporative Emission (NON vented cap-UNLEADED gas).

(2) Without Evaporative Emission (VENTED cap-LEADED gas).

Which type of cap does your truck have?

 

Non vented cap

-Jameson

 

I've got a locking gas cap and I've never had a single problem with it. I'll upload a pic of it when I get home along with model if it says on it.

 

D7UZ-9030-F (replaced D5TZ-9030-E) .. Non Vented Fuel Cap-Chrome w/2 keys - 3 7/8" O.D. (Motorcraft FC-788) / Obsolete

Applications: 1975 E/F100/350 from serial number W80,001 / 1976 E/F100/350 / 1977 E150/350.

NOS PARTS SOURCE in Olathe KS has ONE = 913-220-5746.

WESLEY OBSOLETE PARTS in Liberty KY has ONE = 606-787-5293.

GREEN SALES CO. in Cincinnati OH has TWO = 800-543-4959.

SOEBY MOTOR CO. in Walhalla ND has THREE = 701-549-3711.

CARPENTER NOS OBSOLETE PARTS in Concord NC has FOUR = 800-476-9653.

 

Happy the subject of gas caps showed up.

Having a major problem finding a twist type gas cap for 1973 F250 with
internal panel door access for rear tank.

Removed the auxiliary gas tank that also has a panel door.

Only caps available, aftermaket, are the external panel type with a large diameter chrome plated plate for the twist bar.

Need help finding the correct part number.

Believe the cap fitment is
(1) With Evaporative Emission (NON vented cap-UNLEADED gas).

There is a line from the rear tank to a carbon filter in the front
Believe this is the evaporative emission type.

 

I don't know what kind of cap you got, but mine sucks. I need it vented because that's what the diesel fuel system requires, but it didn't even come close to sealing when I got it. My solution was going to the parts store and getting a gasket of the right diameter and using RTV black to put it on top of the seal that was already there (but not thick enough). It works, but still leaks a little. I think it wouldn't leak if I had gotten a gasket that was a hair thicker.

 

1973/76 Styleside pickups have exposed fuel caps. Aftermarket fuel tanks have a door that is usually riveted to the bedside.

Since the tank is aftermarket, there is no Ford part number for the fuel cap.

 

Both the rear tank and the auxiliary gasoline tanks on my 1973 F250 camper special are original equipment. The truck panels are style side

There are two access doors on the drivers side that are original.

The external type gasoline caps will not fit through the hinged access doors.

Have a 1976 F250 XLT Ranger with external gasoline caps with style side panels.

No problem finding cap for external type.

Unable to find cap for the internal type with access door.

 

I would try and retrofit a release lever from the cab from a Volvo or similar .. The trial hardware could be gotten from pull-n-save for cheap .. I have dogs where I live and a Mossberg 12 gauge pump

 

As original: 1977/79 F100/350 Styleside mid-ship & aft axle tanks have fuel doors, 1973/76 F100/350 Styleside mid-ship and aft axle tanks have exposed fuel caps.

 

WOW! Have been farmitised!
Puzzle now solved!

Looked on "Bing" search for 1973 F250 camper special images.
All the style side beds have two external fuel caps, no access doors.

Looked on "Bing" search for 1977 F250 camper special images
All style side beds have two internal fuel caps with access doors.

My titled 1973 F250 with FE390/C6 must have a 1977-1979 bed.

The aluminum trim from cab to bed match, perfectly.
The bed is the same color as the cab. The original creme color in the two tone paint color skeme has been changed to match the brown.

Believe you are correct that the fuel fill necks are aftermarket.

This probably why unable to find a fuel cap that fits.

The original 1977/79 fuel fill necks were probably not transfered with the bed swap.

Have a STANT PN 10810 that fits a stock Ford truck 1977-1979, styleside. This cap does not fit, which proves the fuel fill neck is aftermarket. However, will machine off the tips of ears and maybe, then the cap will fit up. if not, May have to find a 1977-78 OEM fuel fill neck.

There is no spring loaded flapper valve in my current after market fuel fill neck.

At some model year the flapper valve was incorporated in the fuel fill neck with size restriction opening for the pump nozzle.

Unleaded fuel replaced leaded fuel somewhere in the early 80's.
Remember with unleaded fuel replacing leaded fuel, the pump nozzle was smaller diameter than the leaded fuel nozzle. With size restriction in the fuel fill neck only unleaded fuel could be used.

According the AZ data base 77 & 78( evaporative, non pressurized) fuel caps are different than the 1979( non evaporative, pressurized) fuel cap for the style side application while STANT shows the pn 10810 for 77-79.

Believe the flapper valve was incorporated in 1979, but states had different requirements.

 

When I got my truck, a '77 with dual tanks, it had a new looking, but poorly fitting cap on the mid tank, and a drilled out locking cap that was just barely on. I went to Autozone and bought two new caps that ended up not fitting...too loose. I returned them, and ordered the "correct" ones from Dennis Carpenter. They don't fit either! They are just as loose as the ones from Autozone. My truck most certainly has the original filler necks.

Since I'm already replacing the filler neck hoses, I will go ahead and remove a filler neck and take it to the parts store and try different caps til I find one that fits.

David

 

rougeriver: try stant 11910 cap it fits my 1977 f150, it's an emission type cap.

raven3: do you think that your filler necks are aftermarket or could they be cut down originals? You just might have you just might have to find others of a known year and then find caps for them.

 

Went to NAPA with my filler neck, and got the correct cap. They only had one, but at least I know what fits it. It's NAPA Balkamp #703-1684.
My truck was ordered with locking caps, but I doubt I will go with those again. They would have different keys unless I went to a locksmith and had them keyed the same.

David