Any way to seal a carb bowl with porosity?

[ed729]

I have a 1964 ford 2000 4-cylinder with a marvel schebler tsx765 carb. It s always had a slow leak, even with the fuel petcock off it will leak about a drop a day. I ve tried a full rebuild kit and I ve got my float height set right. The carb bowl gasket and intake side of the carb are dry so I don t think it s a float height or float valve issue. Both plugs on the bottom of carb are new and tight. It seems like fuel is seeping through porosity at the front of the carb about halfway up the bowl. I have a couple questions:

1) is there any product I can use to seal the carb bowl?
2) what is the best replacement option? Has anybody had luck with aftermarket like what Steiner sells?

 

[Hobo,NC]

First gas will seep uphill.

You can rig up a external float gauge, take the drain plug out use a fitting with a length of clear hose and run it up the side of the carb.

Are spray the outside of the carb with foot powder and observe. Until you prove it I don't think its porosity.

 

[Tim PloughNman Daley RIP]

I highly doubt the carb unit has a casting defect (porosity) as you say. By the looks, your oil filter shows signs that fue has been dripping on it. Id say your gasket is
faulty, or the leak is coming from either the Main Jet Screw, the Sediment Bulb inlet port. The latter uses a 1/8 NPT port so if either the male or female threads got
boogered up, that would cause a poor seal. You could remove and dismantle the entire carb, sandblast the castings, then Magna-Flux them and inspect with a Back Light for
any cracks.



Tim Daley (MI)

 

[ed729]

(quoted from post at 04:18:35 05/26/23)
First gas will seep uphill.

You can rig up a external float gauge, take the drain plug out use a fitting with a length of clear hose and run it up the side of the carb.

Are spray the outside of the carb with foot powder and observe. Until you prove it I don't think its porosity.

I have done exactly what you said about a week ago and the fuel height in the bowl is steady and well below the gasket surface. When I pull the intake off and look in the carb from the intake side it s dry. When I ve had issues with float or float valve in the past that s usually where it s ran out at.

 

[ed729]

I’ve had issues in the past with leaky float valve so the oil filter looks worse. It’s like a drop a day at most now.

I ve tried the original steel plug and the brass plug that came with the kit. I guess I could try some kind of gas proof thread sealer. The needle plug is as tight as I can get it without stripping it.

This post was edited by ed729 on 05/26/2023 at 05:25 am.

 

[Jim.ME]

Looks like seepage from the inlet connection to me.

 

[showcrop]

What JimMe. posted. Gasoila

 

[ed729]

You can t tell from the picture, but the inlet connection gaskets are dry. I ve had those leak before too and I could tell by the wetness around the gasket. I ve had about every kind of leak and this is the last one I can t figure out.

 

[showcrop]

(quoted from post at 05:58:22 05/26/23)
You can t tell from the picture, but the inlet connection gaskets are dry. I ve had those leak before too and I could tell by the wetness around the gasket. I ve had about every kind of leak and this is the last one I can t figure out.

As you know gasoline evaporates very quickly. At one drop per day you need to set up an alarm system that will activate to advise you when the daily drip lands so that you can go and inspect immediately for the moisture on the gasket.

 

[BryGuy]

My eyes aren't calibrated but the oil filter with the gas residue on it looks like a blueish color, gas could be dripping all the
way down the bowl and taking a little bit of blue paint with it? That may rule out the bottom plugs. Fuel inlet or gasket on the
side mounted bowl? I had a leaker on a 640 and it ended up being the small red gasket with connecting banjo bolt.

 

[ed729]

(quoted from post at 06:28:05 05/26/23) My eyes aren't calibrated but the oil filter with the gas residue on it looks like a blueish color, gas could be dripping all the
way down the bowl and taking a little bit of blue paint with it? That may rule out the bottom plugs. Fuel inlet or gasket on the
side mounted bowl? I had a leaker on a 640 and it ended up being the small red gasket with connecting banjo bolt.

The 1 drip a day was more of a one drip that actually makes it to the bottom of the carb and falls off. The front and bottom of the bowl stays wet. If I and leaking at the inlet it s strange that it s dry up there but wet at the mid point of the bowl and down

 

[Ozlander]

I would replace the gasket between the filter and the carb.

 

[Eman85]

(quoted from post at 04:18:35 05/26/23)
First gas will seep uphill.

You can rig up a external float gauge, take the drain plug out use a fitting with a length of clear hose and run it up the side of the carb.

Are spray the outside of the carb with foot powder and observe. Until you prove it I don't think its porosity.

The foot powder trick will show you the path of the leak.

 

[Tequila]

Yes, clean the inside then 2-part epoxy inside the bowl. It will last for years. You can do the outside, if the inside has vents or jets