1951 Cad Fuel Tank compression fitting

[ferdinard]

I have a 1951 cadillac, fuel was leaking around the compression fitting that screws into the gas tank.  After taking it a loose I found that it is missing a brass line block that should be between the gas tank and the fuel line.  Without that piece I can not stop the line from leaking.  Does anyone know where I can find one?

[Jeff Maltby 4194]

I can assist you ? Check your mail :<)

[jmurrayent]

Old topic, but I have the same problem.  I had my tank boiled out and upon installation found that the threads on the compression fitting bottom out before the fuel line seats in the tank and is therefore loose.  Did I lose an o-ring or a ferrel?  I looked at another tank I have and it looks the same.  Shop manual is no help.
Thanks,
Allen

[Jeff Maltby 4194]

It's a brass bushing that drops inside that the fuel line compresses to seal.

[jmurrayent]

Hi Jeff, I sent you an email.  Where do I get this bushing and why didn't I see one fall out when I disconnected the line?
Thanks,
Allen

[D.Yaros]

Generally, the ferrule or compression fitting, once tightened, is tight on the line and not likely to fall off.  So, the first place to look for the old fitting would be on the end of the old gas line.

I would think the compression fitting would be readily available from places like NAPA?    All one needs to know is the diameter of the line on which the fitting is to be installed.

[Dave Ventresca]

the NAPA fittings are generic and don't work. too short, too weak;the original is very thick.  . someone is also repopping those. Dave

[Jeff Maltby 4194]

My 49 reproduction. 50 up are similar less smaller OD.

[jmurrayent]

Jeff, thanks for the photos and the dimensions you emailed to me.   I think I found a solution without having to go to a machine shop.  I'm not sure if it will work since the fitting seals to the tank bung with a washer instead of the inverted flare on the pickup tube.  If the pickup tube needs the pressure of the flare to seal to the tank bung I'll be sucking air.  Will keep you all posted......

[Jeff Maltby 4194]

Here's the drawing Bill Balkie made. 49 bushing on left-57 on right.

The other key to these is to measure the inner diameter of the tank nut threads to make sure it will fit in and yes Jim, the bushing seals both ends with main line installed 49 and up, while pre 49 tanks didn't use a bushing.

[jmurrayent]

Here's an update:  I decided not to try my first setup above since the inverted flare inside the tank would not be sealed, I didn't want to experiment and have to pull the tank out again.  Instead, I went to Napa auto parts and got an inverted flare adaptor to screw into to tank.  It was barely long enough to seat against the flare inside the tank with about 1/16" to spare, I needed a coupler for the original fuel line also (see photo).  I have seen a similar flare fitting with a longer nose on it, but my Napa didn't carry it.

Lastly, as I was doing all this, I found the original flare spacer lying on the garage floor where I removed the tank! After I found the spacer, I decided to go check the dirt where I removed the second tank and sure enough, found the other spacer. 

Moral to this story:  Don't be an idiot like me!

Second photo is of the original spacers.

Thanks Jeff for all the help,
Allen

[John Washburn CLC 1067 Sadly deceased.]

Jeff,

As to the "Spacer in Fuel Tank For Outlet Pipe", Group 12.2860, It shows:
1948-49             Part # 145 5530
1950-1957          Part # 145 7033

jw