brake line

I have replaced the complete left side of my spirit brake lines from wheel cylinder to p valve problem is I am using a flared brass fitting and I cannot stop the fitting to stop leaking from the 3/16 line to the fitting people are telling me that I should use the original fitting and flare the 3/16 line. I have changed break lines with all my cars I have never seen anything like this.

Are you using compression fittings that are leaking? What type of line are you using? I've been using CuNi line and it bends and flares really well.

You need double flares. the fitting isn't the seal.

https://www.youtube.com/watch?v=Irmh7B7OnHQ

Napa sells various lengths of straight prefabricated copper/nickel brake line now with double flare/fittings all ready to bend up and install.