12 replies to this topic

[BlueJay73]

My '99 has a black metal flapper just inside the top of the fuel filler neck. That flapper actuates a little black plastic slider that covers and uncovers either one or both (don't know if it covers one or both) of the openings of the two small metal lines that are soldered/brazed to the side of the filler neck. When a gas nozzle is inserted into the fuel filler neck, it pushes the flapper down and the flapper pushes the little plastic slider up, uncovering the openings to the metal lines. When the gas cap is screwed on, the gas cap pushes the slider back down, covering the openings. (could be visa versa?)

Question:  In gutting the fuel filler neck, do you remove only the metal flapper and leave the slider mechanism in place and intact, or remove it all?

If all is removed, then those openings to the two small metal lines are always open.

Thanks

[Ron Alan]

Though I have never actually confirmed/read a rule about the filler neck, I just followed the crowd and assumed cutting all out was fine. On the 99(race car)you can just eliminate the 2 small tubes functions by looping both rubber hoses to the same side. In other words...use one rubber hose in between the 2 outlets at the filler neck and the other at the gas tank. I remove the filler neck from the car and place in a vice. Forget the exact size...but around a 2" hole saw bit will slide in the top of the filler neck. Carefully use your drill to cut down the tube. It will leave some edges/burrs to file a little but will not touch the outside structure.

[BlueJay73]

Hi Ron, thanks for the response.

So, I removed the entire flapper/slider mechanism. Nothing now but an empty, hollow neck.

The two small metal line orifices are now always open in the filler neck. 

Can I just leave it all alone, connect up the rubber hoses the way they were, and not do any workaround at all?

[Ron Alan]

Yes.

 

I forget what the reason was we basically eliminate the 2 small pipes function...but because my cars are used in endurance races and we stuff the tanks with fuel...that may have had something to do with it. The bigger tube is your vent. Small ones something to do with emissions?

[BlueJay73]

Yeah, I only asked about leaving it alone and reattaching the small lines hoses the way they were, because I don't understand your instructions on how to do the workaround. I don't want to make any mistakes concerning routing of fuel lines.

I've seen pictures of the filler neck on ebay for '99's, and they don't have those two small metal lines at all; just the one larger vent tube.

I don't understand that either.

[BlueJay73]

I think one of those small lines goes to the charcoal canister.

[Ron Alan]

I think 99 cars(maybe 2000)are the only year with the 2 small pipes. After that the design changed. 

[BlueJay73]

Ron,

could you explain again what you mean, how to do it, by " looping both rubber hoses to the same side. In other words...use one rubber hose in between the 2 outlets at the filler neck and the other at the gas tank."

Explain it like you're talking to a 3 yr old... or a dog.

[BlueJay73]

Oh wait. You mean connect the two small metal tubes coming out of the filler neck to each other with one rubber hose (like jumping them together); and do the same thing to the two inlets on the gas tank side. That'll make it like they aren't there at all.

[Ron Alan]

^^^ you got it! Sorry if my explanation was lacking! 

[BlueJay73]

Any idea what happens to the functions that these hoses formerly supplied? We’ve cut off the hoses’ routes to their intended destinations, but the intended destinations are still there. Hope the car doesn’t care.

[Steve Scheifler]

Any idea what happens to the functions that these hoses formerly supplied? We’ve cut off the hoses’ routes to their intended destinations, but the intended destinations are still there. Hope the car doesn’t care.

You’ll find an explicit rule added to the GCR to allow this because several top shops concluded it was a net positive.

[BlueJay73]

Great! Thanks for the help everybody.