The Ford Barn

29Cabriolet · 03-22-2016, 07:35 AM

My car is a 29 Cabriolet but I'm visiting this site because the engine in my car is a 32 Model B. I am in the process of rebuilding a carb and have a question regarding the housing for the GAV needle valve and seat. How is the housing and seat removed from the lower body? Assuming it is threaded, I tried to remove it with pliers but it won't budge. It does not have a hex as on earlier models. I spoke to the rebuilder at Bratton's who said he'd never seen one like that. I was hoping someone on this forum can offer some advice. Here's a couple pictures.

Many thanks for all advice or suggestions!

29Cabriolet
a.k.a. Stan

Mark in MT · 03-22-2016, 08:44 AM

The gav housing is pressed into the base. To remove them I made a little slide hammer that screws in where the needle goes. It is an oddball thread pitch, 1/4-24 tpi I think. A couple raps and out it comes. Don't lose the little spring. And washer under the housing, it keeps the needle from self adjusting.

29Cabriolet · 03-22-2016, 02:37 PM

Quote:

Originally Posted by Mark in MT

The gav housing is pressed into the base. To remove them I made a little slide hammer that screws in where the needle goes. It is an oddball thread pitch, 1/4-24 tpi I think. A couple raps and out it comes. Don't lose the little spring. And washer under the housing, it keeps the needle from self adjusting.

Thanks for the reply! I guessed it wasn't threaded since it wouldn't budge by twisting. And you've confirmed it!

I'll give it a try.

DavidG · 03-22-2016, 02:50 PM

Bratton's carburetor rebuilder shouldn't be allowed to take phone calls given that his lack of knowledge is a liability to their business. All, not just a few, oval bowl '32-'34 Zenith carburetors are constructed in this manner.

rotorwrench · 03-22-2016, 03:47 PM

Bratton's is primarily a Model A parts supplier. They likely don't get much call for Model B stuff.

ursus · 03-22-2016, 03:49 PM

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Unless there is some compelling reason to remove it, i.e., damaged threads or accumulated crud, I would leave it alone. It is very easy to damage the Model B GAV housing - some are hard to remove.

DavidG · 03-22-2016, 05:09 PM

I second ursus' counsel. The key word being "compelling". If it is strictly for cleaning and painting purposes, leave it be.

1931 flamingo · 03-22-2016, 05:41 PM

PM sent.
Paul in CT

Doctor's Ford · 03-22-2016, 07:13 PM

I just replaced mine with this kit provided by Renner's Corner. Mine became loose so I had to replace it. Spoke with Dave Renner who advised on the procedure to follow. The photo shows the order of the internal components. The housing for the GAV needle on the model B is pressed down, no threads. Dave suggested to put a fine coat of a threadlocker like green 3M on the GAV housing before inserting into place. I used blue Permatex which I had available and then pushed into place with gentle blows with a piece of wood. It will likely get deformed when removing with a plier but since it is not threaded I think that will be the only way to get it out.

jim1932 · 03-22-2016, 08:28 PM

I did mine the easy way and sent the whole thing to Renner for a rebuild. Well worth it.

v8nut · 03-23-2016, 04:19 PM

I have two Model B's and have never used parts labeled "C" and "D" in the photo above and I don't see them on the Ford parts book diagram. What is their purpose? Am I reading it right that they go between the seat and the needle valve?

ursus · 03-23-2016, 05:33 PM

Those parts do go between the seat and the end of the GAV housing. They perform the same function as the extended brass "fingers" and ring on the Model A GAV, which is to maintain tension on the needle so that it stays in position.

v8nut · 03-23-2016, 08:04 PM

One more question, I am still confused. In my post above I meant to refer to parts D and E in the picture. Were these used originally (I don't see them in the parts books or catalogs) or are they an upgrade?? It looks like they go inside the GAV tube below the needle is that right? In the layout it looks like they go in the carb housing before the tube which seems strange to me. Thanks for your help. Jim

ursus · 03-23-2016, 10:57 PM

I had assumed the intent of your question and answered it in post #13. Parts D and E are installed first inside the lower carb body and the tube is installed after them . Study a picture of the Model A GAV housing tube and you will see that there is an internal extension that performs the same function as the spring and washer in the Model B carb.

03-22-2016, 08:44 AM	#2
Mark in MT Senior Member Join Date: May 2010 Location: Western MT Posts: 218	Re: Model B 4 cyl Zentith Carb The gav housing is pressed into the base. To remove them I made a little slide hammer that screws in where the needle goes. It is an oddball thread pitch, 1/4-24 tpi I think. A couple raps and out it comes. Don't lose the little spring. And washer under the housing, it keeps the needle from self adjusting. __________________ Mark in MT Always looking for another opportunity to be wrong.

03-22-2016, 02:50 PM	#4
DavidG Senior Member Join Date: May 2010 Location: southeastern Michigan Posts: 10,101	Re: Model B 4 cyl Zentith Carb Bratton's carburetor rebuilder shouldn't be allowed to take phone calls given that his lack of knowledge is a liability to their business. All, not just a few, oval bowl '32-'34 Zenith carburetors are constructed in this manner.

03-22-2016, 03:47 PM	#5
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,426	Re: Model B 4 cyl Zentith Carb Bratton's is primarily a Model A parts supplier. They likely don't get much call for Model B stuff.

03-22-2016, 03:49 PM	#6
ursus Senior Member Join Date: May 2010 Location: Oregon Posts: 1,375	Re: Model B 4 cyl Zentith Carb Sponsored Links (Register now to hide all advertisements) Unless there is some compelling reason to remove it, i.e., damaged threads or accumulated crud, I would leave it alone. It is very easy to damage the Model B GAV housing - some are hard to remove.

03-22-2016, 05:09 PM	#7
DavidG Senior Member Join Date: May 2010 Location: southeastern Michigan Posts: 10,101	Re: Model B 4 cyl Zentith Carb I second ursus' counsel. The key word being "compelling". If it is strictly for cleaning and painting purposes, leave it be.

03-22-2016, 05:41 PM	#8
1931 flamingo Senior Member Join Date: May 2010 Location: new britain,ct 06052 Posts: 9,390	Re: Model B 4 cyl Zentith Carb PM sent. Paul in CT

03-22-2016, 08:28 PM	#10
jim1932 Senior Member Join Date: Oct 2010 Location: Hancock, MA Posts: 2,781	Re: Model B 4 cyl Zentith Carb I did mine the easy way and sent the whole thing to Renner for a rebuild. Well worth it. __________________ Short URL: http://smu.gs/14g7eDW

03-23-2016, 04:19 PM	#11
v8nut Senior Member Join Date: Dec 2010 Location: San Jose, CA Posts: 202	Re: Model B 4 cyl Zentith Carb I have two Model B's and have never used parts labeled "C" and "D" in the photo above and I don't see them on the Ford parts book diagram. What is their purpose? Am I reading it right that they go between the seat and the needle valve?

03-23-2016, 05:33 PM	#12
ursus Senior Member Join Date: May 2010 Location: Oregon Posts: 1,375	Re: Model B 4 cyl Zentith Carb Those parts do go between the seat and the end of the GAV housing. They perform the same function as the extended brass "fingers" and ring on the Model A GAV, which is to maintain tension on the needle so that it stays in position.

03-23-2016, 08:04 PM	#13
v8nut Senior Member Join Date: Dec 2010 Location: San Jose, CA Posts: 202	Re: Model B 4 cyl Zentith Carb One more question, I am still confused. In my post above I meant to refer to parts D and E in the picture. Were these used originally (I don't see them in the parts books or catalogs) or are they an upgrade?? It looks like they go inside the GAV tube below the needle is that right? In the layout it looks like they go in the carb housing before the tube which seems strange to me. Thanks for your help. Jim

03-23-2016, 10:57 PM	#14
ursus Senior Member Join Date: May 2010 Location: Oregon Posts: 1,375	Re: Model B 4 cyl Zentith Carb I had assumed the intent of your question and answered it in post #13. Parts D and E are installed first inside the lower carb body and the tube is installed after them . Study a picture of the Model A GAV housing tube and you will see that there is an internal extension that performs the same function as the spring and washer in the Model B carb.