Best way,to seal?

[Abodybomber]

Getting rid,of all the rubber transmission line,on the cooler lines. Going to 5/16" hard line,custom bent as needed. Using off the shelf hard lines,hand problems with the inverted flare nuts,leaking at the brass inverted unions before. Was thinking,Permatex no.2. Any suggestions?

 

[daliant]

Cut the flare off and re-do it, there could be a burr on the fitting or on the flared line itself preventing a good seal. permetex wont seal a flared joint.

 

[bad440]

double flare the lines

 

[Woods74]

On top of the above, I'd lube very well before flaring.