Tonight I lost my original gas cap. I walked a mile with a flashlight to attempt to find it. My attempt failed! The reason I was willing to look like an idiot walking down the highway with a flashlight is the fact that I felt vert lucky to still have that old cap. Reason being it seems like the ones offered by places like AutoZone are not identical but more importantly they are not vented. I have a friend that has one and he talks of having to crack the cap periodically to release the vacuum and allow the fuel pump to work.

I hope I can still locate one like I had. It was stainless and perfectly smooth. The newer ones have a flat spot in the center and some kind of sticker. I forget what it says. I am just big on original equipment. Plus I want the part to work.

Anybody ever had any issues with replacement caps? Can you still get OEM?

 

Try doing a online search for LMCtruck. (SOrry can't give out websites on this forum, but you'll figure it out.) Anyway, get the catalog for your truck, should arive in about 1-2 weeks. It has a couple different types (locking, standard, and lock flip). Also autozone online might have a better selection, although Id go threw LMC. Also, don't forget ebay if you want an original, original.
Hope this helps...

 

interesting, when i bought my truck it came with a locking gas cap, now I never considered it might need to be vented or I might have fuel delivery problems, that's somthing ill need to check into.

 

They didn't come out with the non-vented type caps until they started with the emissions equipment in 1974, or Calif. trucks around 1970. Before that they were vented. Your truck calls for B6TZ 9030-A, vented, anti-surge chrome cap.

Miller Obs vestal, NY 1-800-546-7278 qty 2 in stock
Dennis Carpenter Charlotte, NC 1-800-476-9653 qty 10 in stock
Green Sales Cinci, Oh. 1-800-543-4959 qty 2
Wesley Obs Liberty, Ky 1-606-787-5293 qty 9

These are just a few that show it. It was used way back into the 50's. You might try your local Ford dealer to see if it can be ordered. Just give him the number and they can look in the price book. If it's there. it's available.

Barry

 

Stant makes a vented cap, available at most local discount parts retailers.

 

I've heard that running a non-vented cap on older vehicicles can not only cause fuel delivery problems, but can actually create enough vacuum to collapse the tank in some cases.

There's usually a way to drill a tiny hole somewhere in a new style cap, to let the tank breathe.

John '63 223 Unibody

 

The way my friend has been going on about his cap, it is a pretty big deal. He has not had complete fuel delivery failure which is what will happen when enough negative pressure overcomes the pumps suction ability. He has mentioned a performance change as of late but I can't say it is because of the cap. He also has said that after a day of driving with usually around 1/4 tank of fuel he will release the cap and gets a very powerull rush of air. His trip is around 40 miles.

We do know one thing at least. If there were no need for a vent the factory would have never designed vented caps. Right?

I should know by tomorrow hopefully the differences and availability of the two lookalike stainless caps. I may have time to check with Ford. Thanks to Barry for that Ford part #!

 

Well I have tried an AutoZone replacement and there is no problem. The cap is vented and like Barry wrote anti-surge. The anti-surge part is the thing that I believe alarms my friend. I guess the movement of gasoline causes air pressure. That pressure probably does not build up with a likely leaky original cap. So when James went out and got his new cap that had a good seal he heard the rush of air every time he loosened it and thought there may be a problem. He actually told me he was afraid that the pressure may rupture his tank. I don't think that there should be enough pressure to blow your hat off of your head but James stated that it happened. Who knows?

I will say that I have owned my share of 50's-60's vehicles and I can't remember having any that built up pressure in the tank. Then again I never put a NEW cap on one. My 65 now has some pressure that builds up with the new cap but nothing as drastic as James tells me about.

The whole thing really makes sense as far as the venting issue. The cap needs to vent inward but does not need to vent outward. If it did you would loose fuel going around corners. A one way valve does this job.

 

I bought a locking vented cap for my 1971 F-100 (after NAPA gave me the wrong one) from this site ( www.motorhaven.com), it was a Stant.

 

GregTruck, I have one I was going to put on Ebay tonight. Let me know if you are interested. Randy