Hello,
Thanks for the input. No problem on the float question - I set it as per the instructions in the rebuild kit... and the fuel in the bowl during normal operation (and non-leaking!) is about 2/3rds the way up in the bowl (glass bowl), so it seems ok... but I am beginning to wonder about it.
As far as the 'heat'... I do have a stock fuel pump. The metal line comes up from the fuel pump on the side of the engine, and passes through a fuel filter (metal), and then up to the top of the valuve cover, to another fuel filter (metal) and over the valve cover to a 6" rubber line, and then the final 6-8" of metal line to the
carb...
As far as fuel-resistant gasket materials, I got cork/rubber and thick fiber paper. I am going to replace the glass bowl with a metal one and one of the other gaskets and see what I come up with. Not sure what to do about the possible heat issue. It's funny that it didn't seem to be a problem in the past... It sounds like I should replace the rubber line also? ("use as little rubber line as possible").

Thanks

 

I had a glass bowl carb and a metal bowl carb. The glass one would not seal and the metal bowl did. I never did figure it out. Is it leaking out of the bowl? Can you see it leaking or is it at one level when you check it and at another level when you come back? I know after mine sits for a while, like over the winter or a few weeks etc, I sometimes have to "prime" it with an ounce or two of gas directly in the top of the carb to get it to start. Is that the kind of leak you're talking about?

 

No, the gas is leaking out of the bowl - it's all over the exhaust manifold below it. I've got a metal bowl and am in the process of taking things apart and trying the metal bowl in there and see if it helps. It can't hurt!

 

Does your engine have one of those manifolds where the exhaust is either bolted right to the bottom of the intake, are real close, so the exhaust heats the carb? If so, I'd find some stainless sheet metal and make a heat shield between them. If actually bolted together, figure out a way to insulate between them without screwing up the alignment.

 

Hey, thanks for the input. Yes, the manifold is right below the carb. There is a 'spacer' under the carb (1/2" thick) and then I have 2-3 'gaskets' on top of that as well. I'll take a look at it again, but the more I get into it, the less sure I think that it's heat. This morning, I started it (with a newly assembled, EMPTY fuel bowl), just to fill up the bowl, and shut it off immediately. I went to work and came home, and gas was all over again - so I am thinking it's not heat-related.
Does anyone think it's possible for the gas to be "syphoning" through the fuel line after shut off? I was looking at the fuel line connector, where it meets the carb, and wondering about it... the fuel line runs out of the fuel pump (down low on the passenger side - below the distributor) up to a fuel filter just behind the fan, on top of the valve cover, and then into a short rubber hose (6") then into a steel line (brake line with a compression fitting) (6" with a 90 degree angle going into the carb), all running along the valve cover - parallel to it and over to the carb...
Just a thought - it doesn't SEEM like it would be possible, as the fuel pump (mechanical) is not pumping when the engine isn't running. I loosened the line, and tilted it up a little, just in case.
I did notice that while running, the fuel bowl was just 1/2 full (I adjusted the float a little - making it lower) and after shut off, the fuel bowl filled up completely. I have been out to check on it a couple of times in the last 30 mins since shut off, and no leak so far though... but the night is still young! Thanks again all for the interest and advice. This sure has been frustrating!

 

When it leaks does it completey drain the fuel bowl? or just down to a certain level?
Is there a well plug of any kind in the bottom of the float bowl or in the body of the carb. Sometimes during the manufacturing process they have to drill a hole in the carb that later gets a plug (well plug) put in it. Sometimes these well plugs will be a source of leaks. The old Rochester Quadra-jet carbs are famous for this causing the fuel bowl to completey empty itself and making for long cranking times in the mornings.
We used to gently tap the well plugs on the quadra-jets to reset the plugs and then seal them with a fuel resistant pooky.

Bobby

 

Hi,
It doesn't completely drain - maybe 1/2 way down. I don't THINK (?) it would drain all the way out, as it sat for over a day and didn't get much past 1/2 way.
A well plug? I am not sure. There IS something that looks like a 'plug' underneath the fuel bowl on the outside of the carb. I hadn't noticed it until earlier. It's a round hole, that is "filled" with brass. It seemed like the bottom of the fuel bowl was always "wet" with fuel.
Wondering if it's somehow?!? syphoning, I loosened up the fuel line and changed the angle going into the carb a little (so it's higher), and put another washer under the lower screw to give me a little more 'bite' putting that screw in, as I actually got it to 'bottom out' turning it in when retorquing it (no, I wasn't turning it REAL hard). I replaced that screw with another also, as it seems funny that it turned more than one turn after already being tight (it didn't seem stripped).
Well, let me know what more on the 'well plug', as if it's not on the outside... ?

thanks

 

Here's a manual that may help a little bit;
http://www.tocmp.com/manuals/Carbs/H...l_IHC_53B.html

The places you will find a plug is any area where during the manufacturing process they had to drill intersecting holes in the carb body for fuel passages. The would then plug off the passage at the exterior. I don't know much about the Holley 1904, maybe the link I posted will shed some light on it.

Bobby

 

Thanks. I'll look through and see if I can get any ideas for other possible problems. I noticed on page 3, at the top, there is a photo "Holley Carb model 1904 with altitude adjustment", and you can see the 'plug' under (below-down lower) the fuel bowl, the place I am wondering about. On page 5, it shows that it looks like a 'plug' on the end of the throttle plate shaft, again, underneath the lower screw on the bowl, down a little lower. It's in the throttle body though, so it's probably not what we're talking about. Thanks for the info and site... That's good stuff!

 

It looks like that is the plug to seal off the throttle plate shaft. Probably to keep dirt and gunk from getting in there and causing wear. However, if the carb is leaking internally and the gas in runnign down onto the throttle plates it could very well "weep" out of that area.

I'll read through the article also and see if I can come up with any ideas for you. I love that site as well. Tons of great info and pics
Bobby

 

Try this: run it to get the bowl full, stop it, then discojnnect the fuel line from the carb. (watch out for spilling fuel, there will be some pressure on it). Plug the fuel line or stick it into a small can or something. Any leakage onto the manifold will have come from the carb, for sure.

I think Bobby's onto something, I've seen the plugs get loose. But your observation that the bowl goes from 1/2 full while running, to completely full when you shut down, seems to indicate that the needle is leaking, plain and simple. Does it have a rubber tip, or is it nylon, or solid brass? They make some mighty cheap parts these days.

 

Howdy. As far as the needle... Looks like it has a rubber coating on the tip. It's a brass needle, but as you said, everything in the "kit" is pretty cheap looking. NONE of the parts are identified(!) but there is a diagram, but it even states that the diagram does not reflect the contents of the kit!!! There's no telling what's a brass washer, or fiber, or even what size they are - it was pretty disappointing. Guess I got what I paid for.
Update... I took off the fuel line and changed the angle on it (just in case it was "somehow" syphoning fuel after shut down?!?) and during this, noticed the fuel that ran down seemed to come out at the bottom of the bowl... LOOKING just like the bowl was leaking. Hmmn. Also, it's got the glass bowl, and I only had 3 of the original 'butterfly' clamps, so had to make one (more later), and was never happy with the screws (4 total) - especially the bottom one, as it seemed to 'bottom out' and everytime I went to 'recheck' the screws, the bottom one would turn a full turn (or more). Anyway, I found a different screw with decent looking threads all the way down (the original looked a little thin towards the end) and also put a second flat washer under the screw, and it tightened down good.
I like your idea about filling up the bowl and removing the fuel line. I started the truck up before work, just to fill up the bowl, but got a call and had to leave early, so didn't disconnect anything, and this evening, got home and no leak! I started it and let it run for about 20 minutes to heat up and then shut it off, and as of an hour ago, still no leak... AND the bowl didn't fill up after shut down... I can't imagine how fuel could 'run' into there after the truck was shut down - unless, like you suggest, the needle wasn't seating, but I took it all apart - clean as a whistle, all new parts, and bent the float arm tab UP so it would push the needle up more...
I agree with you - it sure sounds like a needle problem, but it SEEMS like between removing (and angling?) the fuel line - more likely, just reseating it (it's a brake line - no fuel line was available, and now I am suspicious it wasn't sealing well), and the different screw on the bottom, it *might* have taken care of it.
I notice while it's running, the fuel bowl is about 1/2 full now, and you can see the needle moving around (actually turning around/pivoting, and also, going up and down) and the fuel (and air) pumping in... looks strange, but I've never paid much attention to it, and the fuel level is much lower now than before (I adjusted the float)...
Anyway... I'll take it out for a run tomorrow after work or Saturday, and let you guys know. If it leaks again, I'll definately fill it up and remove the line - that's a great idea... but for now, I'll keep my fingers and toes crossed. It does kind of seem like a dog chasing it's tail kind of thing though, trying to fix the symptoms and not the source of the problem. Like a lot of doctors these days...
Any other thoughts (on the needle, or anything else, etc) is more than welcome, but things are looking promising.... Thanks! By the way, even the tech at Holley told me that these carbs are infamous for leaking. He said they run mineral spirits through them on the bench before shipping out, and they're fine, but they leak later in operation!

 

Woohooo.....I'll be keeping my fingers crossed for you.

Gasoline will leak through a much smaller hole than mineral spirits. I once tried my hand at soldering up pinholes is a gas tank in an old 1949 Pontiac. When I was done I tested the tank by filling it with water. After several hours it was still dry as a bone. I thought I was walking in tall cotton so I installed the tank and poured a couple gallons of gasoline in it. It looked like a sprinkler.....agh.

Bobby

 

Yeah, I have a new found 'respect' (or disgust?) for gasoline. I've tried at least a half a dozen sealants - a few "guaranteed" to work with gas. Nope. For the record, the only one I've tried that did NOT break down in gas was... JB Weld! I am sure there's probably something out there that I didn't find, but like I said, I tried a lot.
Thanks again! I'll let you know how it goes...

 

Howdy,
Thought I'd give you all an update on the leaky fuel. Sorry I haven't been on - we had an airshow at the base, and I was tied up 2 days straight!
Anyway, for the most part, the leak has ceased... but today, after setting 2 days, there was some gas there. It wasn't leaking from the fuel line (and running down), but seemed to be coming from around the gasket on the passenger side and running down. Anyway, it's much less than it was. I think I will see how it does for a week or so, and get it out on the road a time or two and decide where to go from there.
If it continues to leak, I *might* take the bowl off and use 2 gaskets. I am not if the original problem was a combination of things - float, fuel line, lower screw, etc... but it's definately better. I sure appreciate all the advice.
I sure wish I could tell you all that I found a great sealant that works with gas... but sorry, I didn't. JB Weld *is* gas-proof! That's the only thing I found so far, but it's not exactly "practical" for a fuel bowl seal... heh!
I'll let you know how Red is doing in a few days... Take care!