Persistent Fuel Leak - Sediment Bowl Inlet

[Ziggster]

Fuel level in filter. Not sure why it’s only half fuel, but somehow fuel must be tricking down to the sediment bowl inlet. The tank is almost full.

[Ziggster]

Earlier this afternoon, I gave a “tug” on the fuel
line going into the sediment bowl inlet. It was a sideways pull because I was wondering if the tube was slightly off-axis to the inlet port. A couple hrs later, and it’s not weeping! Completely dry. Didn’t touch the nut. WTH!?

[petehoovie]

Originally Posted by Ziggster

Fuel level in filter. Not sure why it’s only half fuel, but somehow fuel must be tricking down to the sediment bowl inlet. The tank is almost full.

[Mart]

Those are the ferrules that are part of the nut. Not the best. (in my opinion). Go to a good hardware store or ebay and get some 1/4" ferrules (we call them olives over here).
They will work with those nuts but proper ford nuts are better. Napa might have them. can't remember the number.

Glad you did get it to seal though. If done correctly they ought to be reusable multiple times.

Mart.

[Ziggster]

Originally Posted by Mart

Those are the ferrules that are part of the nut. Not the best. (in my opinion). Go to a good hardware store or ebay and get some 1/4" ferrules (we call them olives over here).
They will work with those nuts but proper ford nuts are better. Napa might have them. can't remember the number.

Glad you did get it to seal though. If done correctly they ought to be reusable multiple times.

Mart.

Sorry Mart, I should have made it clear in that pic, but the ferrule was loose, it’s now just stuck to the nut. I do agree though about your statement, as I recall someone mentioning that previously to me when I was looking for the nuts/ferrules, and that’s why I went with the loose ones.

Joint is still dry. I just cannot believe that a tug on the line solved the issue. We’ll see if it lasts today, as the plan is to fire up the engine for the very first time.

[Ziggster]

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Still weeping. So, removed line. Ferrule now stuck to tube, but looking at the seat area of the housing it looks flat to me. As folks have suggested, I should have checked this out first. What do you guys think?

[petehoovie]

Originally Posted by Ziggster

Still weeping. So, removed line. Ferrule now stuck to tube, but looking at the seat area of the housing it looks flat to me. As folks have suggested, I should have checked this out first. What do you guys think?

[Ziggster]

Checked the fuel pump from my other flathead. It had this fitting in it. It’s flared at both ends, and has a 3/16” OD hole thru it. I would need a female flare nut, and would have to flare the end of my 1/4” tube. Threads into my hsg. Looking at the seat area it looks like there might be a bit of an inverted flare area similar to the one in the other hsg.

[hueyhoolihan]

ferrules once tightened sufficiently are compressed and are generally not removable from the tube. if they were the connection would leak.

this AI definition is pretty a good definition of a flared compression fitting involving the use of a ferrule...

A compression flared fitting with an olive (or ferrule) is a plumbing component used to create a watertight, airtight seal on tubing, typically copper or plastic. The fitting consists of a nut, the compression ring (olive/ferrule), and the fitting body. When the nut is tightened, it compresses the olive onto the tube, creating the secure connection needed for high-pressure applications in plumbing, pneumatic, and hydraulic systems

[petehoovie]

Originally Posted by Ziggster

Checked the fuel pump from my other flathead. It had this fitting in it. It’s flared at both ends, and has a 3/16” OD hole thru it. I would need a female flare nut, and would have to flare the end of my 1/4” tube. Threads into my hsg. Looking at the seat area it looks like there might be a bit of an inverted flare area similar to the one in the other hsg.

[tubman]

You don't by chance have a later (8BA) fuel pump do you? In late '51 Ford changed from a "Ford Nut" on the fuel pump inlet to a pipe thread that needed a fitting. This has caused a lot of confusion and problems over the years.

[Ziggster]

No, unfortunately. Thought this would be easy peasy, so headed back into town. CarQuest had nothing. Same with big box store, as well as a large plumbing store. Note sure of the size, but guy at plumbing store said it was bigger than 1/4” flare fitting, and too small for a 3/8” flare fitting. Said it was probably a 5/16” size (-5).
I recall now all the threads I read a while back about the confusion with these Ford fuel fittings. Oh vey…!

[tubman]

Those threads look kinda "iffy to me; probably caused by someone trying to force something in the past. If there's enough meat, drill it and tap it to the next larger NPT. Then get an appropriate brass fitting to what ever you need.

Plan "B" is a new pump.

[Ziggster]

Brass threads are good on the fitting I removed from the “second” fuel pump assy. Not sure as to the female threads on that fuel pump assy. The threads on my fuel pump assy are fine.
Speaking of threads, the size/pitch of the female thread at the sediment bowl inlet is 1/2”-20. The brass fitting from the second fuel pump assy has the correct size/pitch (1/2”-20). The 45 degree flare on the brass fitting is for a 1/4” OD tube. The “issue” is that according to the size chart in the pic, the 1/2”-20 thread is for a dash 5 (-5) fitting size which is for a 5/16” OD tube.
I’ll McGuyver something up, and post when done.

[tubman]

Are you sure about the inlet being "1/2-20"? That sounds like NPT and seems a bit large for a fuel fitting. Pipe sizes are the inside diameter of the pipe, while tubing sizes are outside diameter; quite a difference.

I think I may have a problem with communication here.

[FlatheadTed]

Fuel line should be coated steel ,But i use copper ,set the feral /olive on a brass seat such as a Stromberg inlet fitting or the female end of your flex line not in the pump .diaphragm
matting surface should be sanded on a flat surface , thick cork or rubber for the boil

[mcgarrett]

The flexible rubber fuel hose is the CORRECT line going into the fuel pump from the steel line coming from the tank - see Bob C.'s post #10 above. It would be advisable to use the proper part there. It's not worth risking a potential fire trying to make something else work.

https://thirdgenauto.com/product/193...-to-pump-hose/

[petehoovie]

Originally Posted by Ziggster

Brass threads are good on the fitting I removed from the “second” fuel pump assy. Not sure as to the female threads on that fuel pump assy. The threads on my fuel pump assy are fine.
Speaking of threads, the size/pitch of the female thread at the sediment bowl inlet is 1/2”-20. The brass fitting from the second fuel pump assy has the correct size/pitch (1/2”-20). The 45 degree flare on the brass fitting is for a 1/4” OD tube. The “issue” is that according to the size chart in the pic, the 1/2”-20 thread is for a dash 5 (-5) fitting size which is for a 5/16” OD tube.
I’ll McGuyver something up, and post when done.

[Ziggster]

Went through the stash of parts from my second flathead. Found another fitting similar to the one posted, but this one has NPT at the other end! Problem solved assuming the 45 degree or whatever that angle is seals against the hsg. I’ll get a hose barb fitting and attach it, and run hose to the filter.

[Ziggster]

Also found the original fuel line from the pump to carb from the second flathead. It has the nuts and ferrules on it like mine, and one of the ferrules is at the edge of the tube, so I don’t feel too bad. lol!