Leaking carb

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66corsaguy
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Leaking carb

Unread post by 66corsaguy » Wed Aug 09, 2017 5:21 pm

Ok I'm going crazy back and forth on this. My carb is just flooding like crazy. I've adjusted float level several times, it's a totally rebuilt carb. What am I doing wrong? It's my 66 secondary. I'm using the mechanical pump
I have an electric pump that I turn on when it's been sitting just to fill the carbs. When I use that fuel flows out of the top balance holes. So I stopped using that but now it just pours out the top. Is the electric fuel pump on even when I think it's off?

This carb use to be on the left side and was giving me problems over there. When I rebuilt I moved it So it's def the carb and it was happening before the rebuild.

Fuel regulator? Why would I need one if I am only using mechanical pump? Maybe I don't understand fuel pumps and the electric one is always
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on? I am still trying to learn this vehicle as a lot of the work was done previous to me and it's the first car I've ever worked on although I've been able to accomplish a lot.

Thanks!!


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terribleted
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Re: Leaking carb

Unread post by terribleted » Wed Aug 09, 2017 6:10 pm

Electric pump running or not it should not spew fuel. The fuel inlet needle seat is not sealing for some reason. Take the top off the carb and recheck the float level condition of needle seat and proper installation of float assist spring. Check for proper closing of the seat. Is the seat defective? Try replacing it.
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bbodie52
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Re: Leaking carb

Unread post by bbodie52 » Wed Aug 09, 2017 6:25 pm

:dontknow: Did you ever try shaking the float near your ear to see if fluid has leaked into a float? Or placed the floats into a bowl of water to see if both floats float on the surface... or sink? If a float has developed a leak, it will never rise to the occasion, regardless of the float settings, making your carburetor a free flow zone.

:link: http://www.google.com/search?safe=activ ... or%20float

Check the carburetor float spring for proper installation...

See the attached DELCO ROCHESTER - Models H, HV Carburetor Service Manual, starting on page 9, for some guidelines on the float bowl and throttle body disassembly. The section on page 10 entitled: INSPECTION OF PARTS provides a list of potential issues to look for. The section on page 11, AIR HORN ASSEMBLY AND INSTALLATION, specifically addresses the float assembly installation and proper installation of the float torsion spring, as shown in the photograph below…
Float Spring.jpg
Float Spring
:chevy:
Attachments
DELCO ROCHESTER - Models H, HV Carburetor Service Manual.pdf
DELCO ROCHESTER - Models H, HV Carburetor Service Manual
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Re: Leaking carb

Unread post by terribleted » Wed Aug 09, 2017 7:38 pm

bbodie52 wrote:
Wed Aug 09, 2017 6:25 pm
:dontknow: Did you ever try shaking the float near your ear to see if fluid has leaked into a float? Or placed the floats into a bowl of water to see if both floats float on the surface... or sink? If a float has developed a leak, it will never rise to the occasion, regardless of the float settings, making your carburetor a free flow zone.

:link: http://www.google.com/search?safe=activ ... or%20float
Good plan I left that out above!!
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dave t
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Re: Leaking carb

Unread post by dave t » Wed Aug 09, 2017 11:18 pm

I had the same problem. After opening up the carb several times I found that I had installed the float spring wrong. Fixing that fixed the fuel overflow. Open up a good carb and compare the spring to the leaky carb. That might be you trouble too.

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66corsaguy
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Re: Leaking carb

Unread post by 66corsaguy » Thu Aug 10, 2017 8:38 am

bbodie52 wrote::dontknow: Did you ever try shaking the float near your ear to see if fluid has leaked into a float? Or placed the floats into a bowl of water to see if both floats float on the surface... or sink? If a float has developed a leak, it will never rise to the occasion, regardless of the float settings, making your carburetor a free flow zone.

:link: http://www.google.com/search?safe=activ ... or%20float

Check the carburetor float spring for proper installation...

See the attached DELCO ROCHESTER - Models H, HV Carburetor Service Manual, starting on page 9, for some guidelines on the float bowl and throttle body disassembly. The section on page 10 entitled: INSPECTION OF PARTS provides a list of potential issues to look for. The section on page 11, AIR HORN ASSEMBLY AND INSTALLATION, specifically addresses the float assembly installation and proper installation of the float torsion spring, as shown in the photograph below…
Float Spring.jpg
:chevy:
Brand new float from clarks because last one did have a leak. But I did recheck and its ok. Checked spring and seems to be ok. Checked float level. It's ok too.


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66corsaguy
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Re: Leaking carb

Unread post by 66corsaguy » Thu Aug 10, 2017 9:24 am

Hey guys there's a second spring type clip that comes in the clarks kit. I don't know how to use it and if I need it. None of my carbs had it but maybe this carb needs it. It's not the spring you see but it has a little u shape. Maybe that's affecting the float? Anyone know how to attach?


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Re: Leaking carb

Unread post by 64powerglide » Thu Aug 10, 2017 10:19 am

Clark's recommended float setting.
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Float setting.jpg
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Re: Leaking carb

Unread post by terribleted » Thu Aug 10, 2017 10:54 am

66corsaguy wrote:
Thu Aug 10, 2017 9:24 am
Hey guys there's a second spring type clip that comes in the clarks kit. I don't know how to use it and if I need it. None of my carbs had it but maybe this carb needs it. It's not the spring you see but it has a little u shape. Maybe that's affecting the float? Anyone know how to attach?


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That part is not used...the little wire thingy with the hook on it.
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bbodie52
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Re: Leaking carb

Unread post by bbodie52 » Thu Aug 10, 2017 11:46 am

If the float floats and is adjusted properly, and you can't see any dirt or any other thing that might be interfering with the needle and seat stopping fuel flow, you may have to rig some sort of bench check where you somehow pump liquid into the fuel inlet in the upper portion of the carburetor while it is suspended over a a tray to catch the fluid. This should allow you to observe what happens when you manually raise the float with your finger to stop the fluid flow. I can only imagine that there is a defect of some type in the needle and seat assembly, or that there might even be a casting flaw or hole somewhere in the upper body casting of the carburetor that is allowing fuel to enter the float bowl even when the valve is closed.

:dontknow:
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toytron
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Re: Leaking carb

Unread post by toytron » Thu Aug 10, 2017 1:32 pm

Corsaguy, could you provide a picture of the little spring you are referring to?

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66corsaguy
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Re: Leaking carb

Unread post by 66corsaguy » Thu Aug 10, 2017 5:36 pm

Image

That's the pin thing. I used it on the left secondary and seems to be ok. I did a close look at the float that clarks sent me. Unfortunately they are used and the main metal float post that holds the spring and leans against the needle was bent and not allowing it to open and close properly. So I filed a small little divot and it seems to fix the over flow. So that problem is resolved. Thank you for that bit of info.

Next question is it possible that my carb would leak from the lower throttle plate that opens into the manifold? Is that a problem you've all heard about? That seems to be a problem area.

And my Venturi is dripping. But I've seen other posts on that that I will refer to. More important is this leak.

Can I plug the leaking carb fuel line so that I can drive the car while I figure out this carb issue?

Thanks to you all for this great resource and your time. I'm so close to getting her back up!

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Re: Leaking carb

Unread post by terribleted » Thu Aug 10, 2017 9:02 pm

You can plug both secondary fuel lines to operate with out the secondaries. Make sure they are closed and throttle linkage removed...not a bad idea to wire them closed so they can not open inadvertently. Another solution is to remove the secondary carbs and install block off plates. You can not just block one as that will run badly due to more carburation on the active side.
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66corsaguy
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Re: Leaking carb

Unread post by 66corsaguy » Fri Aug 11, 2017 2:24 am

terribleted wrote:You can plug both secondary fuel lines to operate with out the secondaries. Make sure they are closed and throttle linkage removed...not a bad idea to wire them closed so they can not open inadvertently. Another solution is to remove the secondary carbs and install block off plates. You can not just block one as that will run badly due to more carburation on the active side.
Ok. I'm going to try this and see about getting a new set of secondaries or try and replace that lower metal post

Thanks again everyone!!


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Re: Leaking carb

Unread post by terribleted » Fri Aug 11, 2017 8:06 am

66corsaguy wrote:
Thu Aug 10, 2017 5:36 pm
Image

That's the pin thing. I used it on the left secondary and seems to be ok. I did a close look at the float that clarks sent me. Unfortunately they are used and the main metal float post that holds the spring and leans against the needle was bent and not allowing it to open and close properly. So I filed a small little divot and it seems to fix the over flow. So that problem is resolved. Thank you for that bit of info.

Next question is it possible that my carb would leak from the lower throttle plate that opens into the manifold? Is that a problem you've all heard about? That seems to be a problem area.

And my Venturi is dripping. But I've seen other posts on that that I will refer to. More important is this leak.

Can I plug the leaking carb fuel line so that I can drive the car while I figure out this carb issue?

Thanks to you all for this great resource and your time. I'm so close to getting her back up!
The little metal tab that hits the needle seat is supposed to be bent. You bend this in or out in order to set the float drop. How did you set your float level? (level is set by bending the small tab in the center of the float arm up or down against the top of the needle valve) Do you have a GM shop manual?? If you installed the little wire hook thing on the other secondary's needle seat it may be interfering with that float opening (holding it closed), this part is not used in the late models carbs (or any Corvair carbs that I have rebuilt...perhaps a 60 model....) and will cause interference.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
https://www.facebook.com/tedsautorestoration/

Located in Snellville, Georgia

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66corsaguy
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Re: Leaking carb

Unread post by 66corsaguy » Fri Aug 11, 2017 3:00 pm

terribleted wrote:
66corsaguy wrote:
Thu Aug 10, 2017 5:36 pm
Image

That's the pin thing. I used it on the left secondary and seems to be ok. I did a close look at the float that clarks sent me. Unfortunately they are used and the main metal float post that holds the spring and leans against the needle was bent and not allowing it to open and close properly. So I filed a small little divot and it seems to fix the over flow. So that problem is resolved. Thank you for that bit of info.

Next question is it possible that my carb would leak from the lower throttle plate that opens into the manifold? Is that a problem you've all heard about? That seems to be a problem area.

And my Venturi is dripping. But I've seen other posts on that that I will refer to. More important is this leak.

Can I plug the leaking carb fuel line so that I can drive the car while I figure out this carb issue?

Thanks to you all for this great resource and your time. I'm so close to getting her back up!
The little metal tab that hits the needle seat is supposed to be bent. You bend this in or out in order to set the float drop. How did you set your float level? (level is set by bending the small tab in the center of the float arm up or down against the top of the needle valve) Do you have a GM shop manual?? If you installed the little wire hook thing on the other secondary's needle seat it may be interfering with that float opening (holding it closed), this part is not used in the late models carbs (or any Corvair carbs that I have rebuilt...perhaps a 60 model....) and will cause interference.
Yes I bend the tabs to set the float but the float clarks sold me was bent in a different spot (the back part behind that tab) and interfering with the needle going up and down.
I have the GM manual and almost all the other books and clarks parts book and these forums but even with reading everything there's still so many unanswered questions!!

It's weird that clarks rebuild kit for the late model would include that pull pin. I am not using it on the leaky carb.

I think the throttle bar that goes thru the lower part of the carb is leaking. Is that common? I can't figure out where else it can be dripping from
I'm going to plug the secondary fuel lines until I can definitively figure out this leak.

I resolved the carb flooding fuel from the top with your all advice!! Very helpful.


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