Ford does sell a cap but I understand it is not "water proof" or leak proof if you roll. There should be no need to worry about washing, I have not pulled it apart to see how it works but if the valve does not get opened to allow free flow into the tank anything above that will drain out a small tube.

 

Thanks, that's what I was thinking with the screw. I had my closed off valance piece with me at Lowe's and it didn't seem to make much of a difference with either piece and thought I'd do the screw bit either way. What I haven't tested yet is whether or not the smaller piece will go all the way into the duct opening. If it does I'll go back and get the piece you used.

 

Scott,
I asked a Ford dealer about a cap, and they couldn't find one in the system.
Got a part number?
Don't know if gas can spill out at the track (assuming I keep the car shinny side up!), but a real cap wouldn't hurt.

 

8U5Z-9C268-B should be pretty standard for all models.

 

Thanks!
I see its also available from a few mail order places.

 

It looks like it comes with a key, is that correct. (not a Trackey thread) but a gas cap key?

 

Correct....... from several online ads:

OEM Ford 2009 2010 2011 F-150 Mustang Locking GAS Fuel Plug CA

 

Great exactly what i was lookin' for!

 

Thanks all. I will have to get one of those locking gas caps but perhaps the new system is more tamperproof than the old style. Anyone know why Ford decided to go to this new fueling system? I assume it may have something to do with emissions or vapor containment?

Sorry Wayne for high jacking the thread regarding brake port duct covers.

 

Chuck, I bought a locking fuel filler plug from Ford's service dept. That should keep anything from getting into the fill pipe.

 

Back on topic. I finished and installed my covers today. I added a black cap bolt so I'll have something to grab onto when I need to remove the covers. The secondary pieces I used aren't needed, you can just use the cap since it won't go in very far, but they help align the cover so I'm using them.

BTW it rained at my track day last weekend and there was a lot of crap inside the ducts.

 

Purchased the locking cap and it arrived yesterday. It's really small compared to "traditional" locking caps. And it does not have a rubber gasket or seal. It's what the name implies......a locking gas cap. You appear to need to have the key inserted in the lock to insert the cap into the fill pipe opening, and then turn the key in the cylinder to lock the cap and remove the key. Here's a couple of photos of the cap

 

A new spin on the front opening for the Boss brake cooling duct. I added the 2" flush fit pipe drain and a 2" x 2" screen behind it to keep the little critters out. I'll super glue the screen in and use PVC glue to mount the flush drain to the part that fits into the lower front fascia. Haven't tried it yet but in non-rain, off-track hard motoring, you can still get some air to those breaks.

PS: If you choose to stop any air, the original cap will still snugly fit over this contraption.