Fuel pump fitting

[dgrinnan]

I have a new fuel pump on my 1947 1/2 ton with a 218.  It is a Carter fuel pump.  Should the outflow connection be a standard flare or a double flare.  A mechanic that was helping me said I should do a double flare but it does not seem to seat very well and if I put any stress (wiggle gently) on the line it want to leak.  I am afraid to over tighten it.  Is it designed for a single flare? Did they even have double flare in 1947 or does it even make any difference either way?       

Edited October 18, 2022 by dgrinnan

[Los_Control]

My original line from the pump to the carburetor is a single flare.

All the fittings are for the brakes, vacuum advance, fuel .....  From a quick google search.

 

The single flare is very identical to the double flare. Although they look a lot alike, the double flare is much stronger and can hold more pressure build up inside the braking system. The double flare is a flare that is especially popular in vehicles imported from Europe.

 

And another opinion.

 

Can I use double flare instead of single flare?

 

 

You'll see double flared lines in automotive brakes, usually in American and Asian models. European vehicles use bubble flared lines, which are similar in safety for high pressure hydraulic lines. If you see single flares on your brake system, replace them right away with double flared lines.

 

My opinion is single flare has worked on my truck for 70 years.

Flaring lines can be a bit tricky, you just need to be careful & pay attention .... sometimes no matter how hard you try a flare will still fail.

A double flare is same as making a single flare except twice as tricky.

[Merle Coggins]

I always use double flare on my lines, fuel, brake, or otherwise. 

[ggdad1951]

I double flare everything.

[Dodgeb4ya]

Factory double flare is used as OE on the fuel line.