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-   -   GAV leaking (https://www.fordbarn.com/forum/showthread.php?t=285850)

cederholm 08-19-2020 02:09 PM

GAV leaking
 

With the air filter removed, and the car not running, the throat of the carb intake is pooling with fuel. I believe my GAV is fully closed so I assume the needle isn't seating fully.

Thoughts/advice?

Thank you,
Carl

Ernie Vitucci 08-19-2020 02:21 PM

Re: GAV leaking
 

Good afternoon...You might with to check your float level...Ernie in Arizona

cederholm 08-19-2020 02:24 PM

Re: GAV leaking
 

Ah, inserting. What is the rule of thumb for setting that?

Quote:

Originally Posted by Ernie Vitucci (Post 1921987)
Good afternoon...You might with to check your float level...Ernie in Arizona


ryanheacox 08-19-2020 03:00 PM

Re: GAV leaking
 

You want the gas level ~5/8" below the gasket, some like 15/16". A good rule of thumb is to have the seam of the float at an even 1" from the casting with the upper half flipped upside down. This info is all for the Zenith. You also want the cap jet to have a depth of 7/16" from the machined surface of the lower half and the main jet to have a depth of 3/8".

cederholm 08-19-2020 03:08 PM

Re: GAV leaking
 

Awesome, thank you.

Quote:

Originally Posted by ryanheacox (Post 1922010)
You want the gas level ~5/8" below the gasket, some like 15/16". A good rule of thumb is to have the seam of the float at an even 1" from the casting with the upper half flipped upside down. This info is all for the Zenith. You also want the cap jet to have a depth of 7/16" from the machined surface of the lower half and the main jet to have a depth of 3/8".


Ed in Maine 08-20-2020 05:48 AM

Re: GAV leaking
 

You should also remove the float valve and wipe it off with Carb Cleaner, Lacquer Thinner or Acetone. Float valves are a problem area with the Model A. It is a good idea to install the small tubular filter into the inlet of the shutoff valve available from Synders and others. I also like a lower float level than 5/8 in. As long as the compensator jet remains flooded at all times, the 5/8 in. float level is not critical. With the float level at 5/8 in., the gas level in the cap and main jets is right at the top of the jets and if you park on a hill going up hill, the carb could leak into the street! I prefer 11/16 in. to 3/4 in. Good luck with your repair, Ed

johnbuckley 08-20-2020 08:20 AM

Re: GAV leaking
 

"With the air filter removed, and the car not running, the throat of the carb intake is pooling with fuel. I believe my GAV is fully closed so I assume the needle isn't seating fully."
The GAV needle won't cause fuel to leak out of the carb, a non sealing GAV needle will cause rich running but will not cause fuel to pool in the throat of the carb.
Your problem is number 1,2,3,4,5,6,7,8,9,10 on the list below you'll probably find it's 1 or 2 if it's been OK up til now:)
Problem: Remedy
1 Leaking/loose float valve gasket: Tighten/reseal/replace
2 Leaking float valve: (or crud stopping it sealing)Replace ( or clean up if possible )
3 Friction on float hinge: Loosen
4 Incorrectly set fuel level: Re-set
5 Hole in float: Repair or replace
6 Too many gaskets on main jet Check
7 Cap jet or main jet too short: Replace
8 Leaking/loose gasket at main jet: Tighten/reseal/ replace
9 Leaking /loose gasket at cap jet: Tighten/replace
10 Leaking or loose GAV housing threads: Tighten/ reseal/ replace
11 Leak at fuel inlet union: Tighten/reseal/replace
12 Loose/leaking gasket at strainer: Tighten/reseal/replace
13 Loose/leaking gasket at drain plug: Tighten/reseal/replace
14 Cracked housing/leaking passage plugs: Repair or replace

redmodelt 08-20-2020 09:53 AM

Re: GAV leaking
 

The GAV is not a shut off. If you try and use it as such you can/will score the tip when trying to close too tight. The GAV does not need to be shut down every time the car is stopped. Once you find it's best position, leave it and only open enough to start the car then return it to the best run position.

cederholm 08-20-2020 02:13 PM

Re: GAV leaking
 

Fantastic info all - I will follow your instructions.

Thanks,
Carl


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