Topic: 2V Carburetor Leak

[Building 3]

I have a low miles (25,000miles) 1966 2V carb car.  I am the third owner.  From what I can tell, the car has been used as a weekend and nice weather car for most of its life, so I am sure the car has not been abused.  This summer the carburetor started to leak at the fuel filter connection to the carburetor. I put on a new fuel filter and gasket and actually the leak got worse.  I called the Permatex hot line and they recommended a product for the threads.  I followed the instructions, but to no avail.  The drip interval is about one second. I was wondering if anyone has run across this problem. I used a magnifying glass to see if the threads inside the carburetor are stripped or cracked, but they seem fine.  So, this is a mystery to me.  I was hoping that someone may have run across this problem in the past and have a recommendation.  Thank you. 

[Hipo giddyup]

 Just a few things i have noted; 1. I try to use a motorcraft filter or NOS when possible. I have tried the filters through the major parts retailers and they need to be snugged up tight in order not to leak (even with the gasket). Not sure why that is. 2. DO NOT over tighten or you could of course risk on damaging the carb or breaking off the threads of the filter in the inlet. I'm sure you will get other advice here as well. Good luck!

[67gtasanjose]

A picture would be worth a thousand words here...It would help to see the filter (with brand name), any gasket provided or not provided and what you are screwing into (the carb or the fitting in the carb)

I recall different versions, but have worked on so many 2100 Autolites, I cannot recall what you should have on your 66

[Building 3]

Here are several photos. (I hope) The leaking area at the union of the carburetor body and the fuel filter, the gasket, and the box the filter came in.  It is a Motorcraft filter, made in China.  The carb number is C6DF  B, A  5GA.  Everything seems fine, except that it leaks. 

[Building 3]

Here is the gasket photo.

[67gtasanjose]

OK, I see the style you have clearly now. Also the same style is used on the 66 4100 4 barrel carbs and the same issue can arise there too.

The gasket is not really intended to "crush" and seal this design. If you look into the opening for the filter, you should be able to see the flare nut seat which was used on earlier (like 65's) cars that had the filter canister on the fuel pump, meaning to read that this design wasn't originally designed to have a filter screwed into in but instead it was designed to simply have a fuel line screwed into it.

The problem usually is that the gasket provided isn't sealing off the gas leak. Fear of over-torquing and stripping the threads keep you from getting a good seal, and rightfully so...they have stripped out on other people because of this. This would be a good explanation for the design change going into 67 where the filters used 1/8" pipe threads (with sealant).

My thoughts are on your leak is it is caused because you are not seating the tapered edge on the front, leading edge of the filter fitting tightly against the seat down inside of the opening of the carb. My thoughts on the washer/gasket (provided with the filter and pictured) is that it isn't what is supposed to actually seal it from leaking, but it is more of a stopgap to keep you from overtightening it. Supporting reasoning for this...Notice how the area of the carburetor body directly around the threaded opening is NOT a machined surface, but it is simply a CAST surface?  A cast surface that has been threaded first, yet never machined following the threading is a recipe for a leak. I doubt the engineers of Ford figured that triangled opening gasket to actually work as a seal, if you get my line of thinking.

SUGGESTED REMEDY: If you feel the threads are as you say good  strong (in your original post) and there seems to be no flaws on the a.) seat on the end of the filter and b.) seat inside the opening of the carb., then just tighten it a bit more. (maybe give it a test for leaks without the gasket provided)

If that doesn't work, I have found before (to help on flawed seats) cone-shaped (flared) copper insert washers to help with sealing flare seats. That could be a good back-up plan as to chancing stripping the threads of the carburetor.

Hope this helps.

Richard

[jwc66k]

I've had problems with that style gasket too. I currently use one with a round hole, and I guess it's about time to find some more.
Jim

[Building 3]

67GTASan Jose:  Thanks for the advice.  All of that makes a lot of sense. I will try that copper gasket and let you know how it goes. I need to be out of town for a while so I will try it when I get back and post the results.