gas tank, fuel pump, or something else?
 

While driving my truck today, it exhibited signs of running out of gas. Looking under the hood, I saw a large stream of bubbles coming up into the fuel pump bowl (it has the gas cover). And the carburetor float bowl was empty. (It has a glass cover, too.) The fuel pump was sending more air than gas to the carburetor. I could see the gas trying to get into the float bowl. It was entering in little spits.) I happened to have a new fuel pump, so after the truck limped home (stopping every few minutes for the gas to fill up the float bowl), I put the new pump in. Same thing: bubbles. I believe the lines are all good. If they weren't, I assume I'd see gas dripping somewhere. I checked the diaphragm in the new pump and it's fine. (So was the old one...) I did rebuild the carburetor a few months ago, but even if there was a problem there, I don't see how that could have anything to do with all the bubbling air in the gas line. I am wondering about the gas tank. It's the original one from 1953. I cleaned it and used a coating designed for gas tanks...I forget where I got it...Eastwood? or Mid Fifty? Anyway, has anyone experienced anything similar? I really don't want to buy a new gas tank, as long as the one that I have isn't leaking. Lastly, it did occur to me that I may have been running out of gas, but I verified that the tank is about 1/3 full.

I would be betting on the gas tank, lots of crud and rust have accumulated in there.
I put up with mine doing the same thing for a couple of years then replaced the tank and no more problems

Ed
near Philadelphia

I just took a look at the tank. I saw that the gas is drawn out from the tank at its top. Obviously, the only way that this could work would be to have a tube inside the tank at that point which extends down to the bottom of it. I'm thinking that if that tube was corroded, the fuel pump would suck in air as well as gas. So, I'm going to fill the tank up full. If the pump stops sucking bubbles, then I've figured out the problem. Except if this turns out to be the problem, what is the fix? Shell out $200 for a new tank?

My SWAG is that your pump is sucking air somewhere. Most likely places are the glass fuel bowl on the pump or the flexible line to the pump. You must have an OHV six cylinder, do you not?
Edit: Ok, seeing your second post on the subject, the tank must be a behind the seat tank in the '53 and pulls from the top. Yeah, don't overlook the pickup tube that goes into the tank.

Success!!! The problem turned out to be the connection at the fuel line and the tank. I cleaned it up and tightened up the fitting and NO BUBBLES. I should have checked this before I made the first post on the topic. I didn't mean to waste anyone's time. My dread was that the pickup tube was rotted out and I that I was going to have to remove the tank, either to replace it or repair it. I still have a long list of other less pressing questions, but at least this little adventure is behind me. Looking backwards, I realize now that if it had been a pickup tube problem, it probably would have revealed itself in the first minute that I started up the engine. There were no bubbles before I started taking the truck out for test drives. :-X03:-X03:-X03:-X03:-X03

Always nice to get the report on the final resolve of any and all problem discussed.

I'm glad you found the issue and it was an easy fix.
Posting your results gives us closure and also may help the next person that something like this happens to.

Good news.

The key for me were the words 'I believe the lines to be good'. Too often we skip a step in trouble shooting: Checking the basics.

That's exactly right. I should have tagged this post to make a search more direct. but even as it is, it may help someone else.

Same thing happened on mine - bubbles in bowl. PO had replaced the tank but failed to use sealer on the threads of the 90° fitting on top of the tank. Glad you figured it out and are back in service.

Have never seen a glass top on a carb, but have one on my fuel pump. Would like to have one on my carb.

The 6 cylinders had them but not the V8 Yblocks.

Holley model 1904, I believe. Glass float chamber cover.