I am working on a '69 truck and it has copper tubing for the fuel lines from the two tanks to the selector and up to a junction near the pump where it becomes metal. I have heard that copper tubing is NOT good for fuel lines. Is copper tubing legal?? safe?? What problems are there in using it?

Thanks!

 

Copper cracks and should not be used for fuel line. Get some steel tubing and replace it.

 

I am in the process of replacing it, but I still wonder about whether it cracks as I and others have always stated. This tubing is on a 20 foot cattle truck that hauled cattle back and forth from summer to winter range for a number of years, the tubing is original to the installation of the cattle bed/racks. There are no cracks in it although there are a few tight bends(almost kinked), but not any sign of cracking or brittleness.

Anybody know of the "official" info?? Not doubting you Eric, I am just curious as much as anything, I am replacing it!!

 

That's interesting Putt. How many miles a year do you think the truck sees?

I'm trying to remember all the copper crap I've had to replace because of cracks. I have visions of flare fittings that were known good and in service for some time before failing. The commonality I notice is that they were already work-hardened from being flared, and subject to vibration. I'm sure I've replaced steel flares subject to vibration also.

No, that's not anything "official", just some observations from under this shady tree.

 

Well for the last 25 years it has seen ZERO miles total!! The truck has 87950 miles on it and the lines look like they were installed at the time the flatbed was installed which was when it was almost new. It hauled cattle for about 10-12 years, so I guess it got about 7500-8000 miles per year. I just thought of something, the fittings are all compression fittings, not flared. I wonder if that has some significance.

 

I would think so. The flaring tool not only works the tubing, but the bending and shaping should make it thinner. Just for grins, make a single flare and a double flare on same sized scrap, then bend the flare out of round with pliers-pretty stiff.

The only place you have a bend in a compression fitting is fore and aft of the ferrule. Not a very big sharp bend, crimped once only.