55.2-59 Leaking at Manifold

[2bo.c10]

Hi Everyone,

Any idea why I'm getting gas leaking here? Ive replaced the grommet between the O-Ring and the exhaust recently and its still leaking. Am I just flooding the carb or does it seem like I have a cracked manifold?

[mongocanfly]

Looks like the carb needs rebuilt

[dsraven]

after running the engine for a couple of minutes to fill the carb and get the fuel pressure up. stop the engine and put something heavy on the gas pedal to block it on the floor. let it sit for a bit, then remove the air filter and look down the throat of the carb. if you see raw fuel down there then the residual fuel pressure in the system is leaking past the inlet valve in the carb and basically bubbling down the throat of the carb. since it is pretty thin it will find it's way out of any cracks and crannies like the joint between the intake and exhaust manifolds in your case. if it is bad enough and you are there at the right time you would see if actually coming out of the float bowl internal bowl vent tube that exits in the throat of the carb.
grab a kit and some carb cleaner, a small nylon brush and one of the wife's cake pans to keep all the parts in. one of those tea leaf caddies is also a great thing to hold the small parts in while you clean them. the steel mesh screen type. take a pic of how everything connects before removing the carb. once it is off use some spray carb/choke cleaner and spray it all down before you start working on it. if unsure of what you are doing take a few pics as you disassemble it and take notes of screw settings etc. before removing any adjustable mixture screws etc turn them in slowly and count the number of turns they are screwed in so you know how much to set them to when you assemble the carb after. look for o rings behind the mixture screws etc that may be stuck in the hole. note how they assemble before you take them all apart. try to keep the old gaskets intact so you can place a new gasket over the old one and ensure the holes are all on the same place. the kits should come with an exploded view so you can go by that for some of it.
or buy a rebuild one and hope for the best. don't give up your core carb until you know the rebuilt one is gonna work.

[dsraven]

as a side note, that red wire looks awful close to the exhaust manifold. maybe reroute or heat shield it while you are working on it.

[2bo.c10]

Originally Posted by dsraven

after running the engine for a couple of minutes to fill the carb and get the fuel pressure up. stop the engine and put something heavy on the gas pedal to block it on the floor. let it sit for a bit, then remove the air filter and look down the throat of the carb. if you see raw fuel down there then the residual fuel pressure in the system is leaking past the inlet valve in the carb and basically bubbling down the throat of the carb. since it is pretty thin it will find it's way out of any cracks and crannies like the joint between the intake and exhaust manifolds in your case. if it is bad enough and you are there at the right time you would see if actually coming out of the float bowl internal bowl vent tube that exits in the throat of the carb.
grab a kit and some carb cleaner, a small nylon brush and one of the wife's cake pans to keep all the parts in. one of those tea leaf caddies is also a great thing to hold the small parts in while you clean them. the steel mesh screen type. take a pic of how everything connects before removing the carb. once it is off use some spray carb/choke cleaner and spray it all down before you start working on it. if unsure of what you are doing take a few pics as you disassemble it and take notes of screw settings etc. before removing any adjustable mixture screws etc turn them in slowly and count the number of turns they are screwed in so you know how much to set them to when you assemble the carb after. look for o rings behind the mixture screws etc that may be stuck in the hole. note how they assemble before you take them all apart. try to keep the old gaskets intact so you can place a new gasket over the old one and ensure the holes are all on the same place. the kits should come with an exploded view so you can go by that for some of it.
or buy a rebuild one and hope for the best. don't give up your core carb until you know the rebuilt one is gonna work.

Thanks for the detailed write up. I am not able to run the engine. I just rewired the truck and got my starter rebuilt. This is the first time I've tried to start it in a few months. I think you're right, the carb needs to be rebuilt. I hope my exhaust manifold isnt cracked though. Ive had a hard time finding a new manifold - all the ones I've seen for sale are the two piece ones and all the intake manifolds I see for sale are to have more than one carb.