1957 Holley 4 barrel leak | Ford Thunderbird forum club group 1955-2005 models
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1957 Holley 4 barrel leak

  • Thread starter Thread starter TbirdFan76
  • Start date Start date
TbirdFan76

TbirdFan76

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Thunderbird Year
1957
After cleaning the carburetor while on the engine using carb cleaner and soft bristle toothbrush a leak occurred. It seems to be coming from the bottom of the front reservoir diaphram.

  1. Is it possible to take the front bowl off the carburetor to inspect and repair the diaphram without removing the carburetor from the engine?
  2. Alternatively Is there a way to remove the accelerator diaphram from the carburetor from the bowl? It would require a tool to remove the screws which are on the bottom diaphram which are not possible to remove with a standard screw driver?
All advise is welcome.

Engine is a 312 Y block with holley 4bbl carburetor. Per Barrett-Jackson Auction listing this is an original car with only cosmetic updates to the convertible top and interior.

Thanks.

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Removing the carb on these cars is one of the easiest things to do. If it's been on there awhile you should use new gaskets to replace any that get disturbed which would include the two large ones for the manifold and the spacer that's under the carb. Since you have a leak which presumably you hope to fix, I would order a rebuild kit before starting to take things apart. It will have the gaskets for the front bowl and I would expect it to have a new diaphragm for the accelerator pump, the things that seem most likely to be leaking from your description. Get the list number off the front of the carb air horn to help in ordering the kit. That daytonaparts place should be able to get you the right kit.
 
After cleaning the carburetor while on the engine using carb cleaner and soft bristle toothbrush a leak occurred. It seems to be coming from the bottom of the front reservoir diaphram.

  1. Is it possible to take the front bowl off the carburetor to inspect and repair the diaphram without removing the carburetor from the engine?
  2. Alternatively Is there a way to remove the accelerator diaphram from the carburetor from the bowl? It would require a tool to remove the screws which are on the bottom diaphram which are not possible to remove with a standard screw driver?
All advise is welcome.

Engine is a 312 Y block with holley 4bbl carburetor. Per Barrett-Jackson Auction listing this is an original car with only cosmetic updates to the convertible top and interior.

Thanks.
Yes, it is possible to remove the front bowl without removing the carburetor from the engine. Years ago, some Holley fuel-bowl screws had a slotted head that required using a flat-blade screwdriver. The common screws used today have a hex head, which require a 5/16-inch wrench. Crack each screw loose, and then continue to remove all four. Each fuel-bowl screw seals to the fuel bowl with a sealing washer. If the washer does not stay with the screw, it’s likely stuck onto the fuel bowl.

100_6762.JPG

100_6787.JPG

The gasket on the fuel bowl may cause the fuel bowl to stick. Do not jam a flat-blade screwdriver or chisel between the fuel bowl and metering block as this can gouge the mating edges. A light tap with a plastic hammer pops it loose.

The accelerator pump on the primary fuel bowl is secured with four 8-32 screws. Use a Phillip screw driver to remove the four screws securing the accelerator pump to the bottom of the fuel bowl.

100_6788.JPG

100_6798.JPG

At this point you will need a new fuel pump diaphragm and check valve, fuel bowl gasket, fuel bowl screw seals and fuel transfer tube seals. Since you are seeing fuel leaks from the gaskets and seals, if it were me I would remove the carburetor and perform a complete overhaul.

doug7740
1955 Thunderbird Blue
 
In addition to the excellent explanation by @doug7740 make sure you get the viton version of the diaphragm. It holds up to the crappy alcohol laden fluid that passes for gasoline today. Most of these diaphragms I have seen were green not black.
 
After cleaning the carburetor while on the engine using carb cleaner and soft bristle toothbrush a leak occurred. It seems to be coming from the bottom of the front reservoir diaphram.

  1. Is it possible to take the front bowl off the carburetor to inspect and repair the diaphram without removing the carburetor from the engine?
  2. Alternatively Is there a way to remove the accelerator diaphram from the carburetor from the bowl? It would require a tool to remove the screws which are on the bottom diaphram which are not possible to remove with a standard screw driver?
All advise is welcome.

Engine is a 312 Y block with holley 4bbl carburetor. Per Barrett-Jackson Auction listing this is an original car with only cosmetic updates to the convertible top and interior.

Thanks.
Put a new edelbrock on it holleys always have a problem like we say at our shop holleys are made to race edelbrock is made to drive thunder road auto .
 
Put a new edelbrock on it holleys always have a problem like we say at our shop holleys are made to race edelbrock is made to drive thunder road auto .
Maybe I'll do that some day, but for now I'm trying to keep the car original. The previous owner bought the car at a Barrett-Jackson auction. I found the auction listing and the description says the car is original except for the soft top and some interior cosmetic items.
 
Maybe I'll do that some day, but for now I'm trying to keep the car original. The previous owner bought the car at a Barrett-Jackson auction. I found the auction listing and the description says the car is original except for the soft top and some interior cosmetic items.
If you want to drive it put the edelbrock keep the holly for posterity I've been an appraiser for years drivability is worth alots.
 
If you want to drive it put the edelbrock keep the holly for posterity I've been an appraiser for years drivability is worth alots.
We are all entitled to our opinions I guess. If you know how to maintain them Holleys are just fine. Personally, that's my opinion.

I drive my '57 with the Holley everywhere including round trip to San Antonio from northern Colorado in 2022 for the national meet with no issues. Driven a few different Edsels from Colorado to Dearborn, Omaha, Minneapolis for the national Edsel meets with their original Holley with no issues. YMMV.

Replaced a worn out Autolite 4100 with a Edelbrock 1406. It was a royal PITA to dial in with the rods and springs. Again, opinions are like belly buttons. Everbody has one.
 
We are all entitled to our opinions I guess. If you know how to maintain them Holleys are just fine. Personally, that's my opinion.

I drive my '57 with the Holley everywhere including round trip to San Antonio from northern Colorado in 2022 for the national meet with no issues. Driven a few different Edsels from Colorado to Dearborn, Omaha, Minneapolis for the national Edsel meets with their original Holley with no issues. YMMV.

Replaced a worn out Autolite 4100 with a Edelbrock 1406. It was a royal PITA to dial in with the rods and springs. Again, opinions are like belly buttons. Everbody has one.
Were all master certified mechanics i base opinions on observation holleys are ok as long as they work ford carbs autolite has less problems so does edelbrock it a fact maby you have an opinion thunder road auto.
 
Update. The kit I ordered is not usable for the Holley LIST 1273-1. The retailer says they don't have any kits for this early Holley.

Anyone have a reliable source for a rebuild kit? Stuck with my leaks!
 
Looks like CASCO may have one:

I say “may” because the item description isn’t very descriptive, and I’m not expert enough to tell by looking at it whether it has everything needed for a 1273-1. So, I would recommend calling them and asking.

I also have an original 1273-1 on my ‘57. When I had to have it rebuilt, I knew that my skills weren’t up to doing it myself, so I sent it to the Holley Custom Speed Shop to have it rebuilt by Holley themselves. If you want to go this route, call them and ask if they’re still doing rebuilds for vintage Holleys. I got the sense that they were not going to be doing so indefinitely.
 
I'm finally doing the rebuild on the carburetor (Holley List 1273-1). I got a kit from Allstate Carburetor. Disassembled and cleaned all the parts with Berryman Chem-Dip Carburetor and Parts Cleaner. Now starting the reassembly with rebuild kit parts.

I have a question regarding the secondary fuel diaphragm. There is a check ball that I'm not sure how to install. Exploded view of the diaphragm, check ball highlighted (see below). Does it just lay loose in the bottom half of the housing? The opening in the bottom is big enough that the check ball falls out when I push the diaphragm up and down. Perhaps when installed it doesn't get moved up as far as I am pushing it so the check ball doesn't fall out?

Exploded View
Holley-1273-1-SecondaryDiaphragm_Exploded_view.JPG
Bottom View of Second Diaphragm
20250104_143027_1.jpg

View of Second Diaphram when installed
20241230_143618_1.jpg

Looking forward to your input. Thanks.
 
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I'm finally doing the rebuild on the carburetor (Holley List 1273-1). I got a kit from Allstate Carburetor. Disassembled and cleaned all the parts with Berryman Chem-Dip Carburetor and Parts Cleaner. Now starting the reassembly with rebuild kit parts.

I have a question regarding the secondary fuel diaphragm. There is a check ball that I'm not sure how to install. Exploded view of the diaphragm, check ball highlighted (see below). Does it just lay loose in the bottom half of the housing? The opening in the bottom is big enough that the check ball falls out when I push the diaphragm up and down. Perhaps when installed it doesn't get moved up as far as I am pushing it so the check ball doesn't fall out?

Exploded View
View attachment 32634
Bottom View of Second Diaphragm
View attachment 32635




Looking forward to your input. Thanks.
The diagram may be a bit misleading. The check ball would go in the vacuum channel that is off to the side in the bottom housing. If you look at the diaphragm there are 5 holes but 4 screws that hold the top to the bottom. The 5th hole aligns with the vacuum source for the upper half of the diaphragm that makes a 90 degree turn in the lower half of the housing. I personally don’t recall a ball check in there, but it’s been years since I did one of the secondary throttle diaphragms since they rarely go bad.
 
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Be careful about sending a carburetor to the Holley Custom Shop. I sent a perfectly good 4150 to them because I wanted the original finish. A $500 complete overhaul later and the carb looks like new. When I installed the carburetor the sealed bowl on the front leaked. I machined a plug and sealed the leak. Then I found they had drilled the secondary air passages and it was dumping fuel into the intake. I called Holley and they informed me that my carburetor had been sublet to an outside carb rebuilder and they cannot warranty someone else’s workmanship? Don’t be misled into thinking Holley is actually doing the work as if it’s better than anyone else.
 
As Pink T-Bird said, the check ball goes in the vacuum channel that is off to the side in the bottom housing. If you look at the diaphragm there are 5 holes, the check ball goes in the 5th hole which is the vacuum source for the upper half of the diaphragm.

doug7740
1955 Thunderbird Blue

Check Ball.jpg


Check Ball 2.JPG
 
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