I was replacing the rubber lines with steel braided lines. Drivers side went perfectly. When I went to do the passengar's side, the nut was tight and I think I stripped some of it. I was using brake / fuel line wrenches. Even tried vice grips.

And ideas how I can loosen the connection between the hard line and the flex hose?

 

Spray a decent amount of penetrant (WD-40, liquid wrench) on the fitting, let it soak for a while, then clamp on a set of vice grips as tight as you can possibly get them on. I had trouble with quite a few cars in this area due to rust and age/sitting untouched for years.

 

Did that. No luck. Should I use a large vice grip? I used the smallest the store had.

 

Yes, a larger pair will do a better job, more leverage and more grip. You may have to replace the fitting on the steel line, or part of the line itself, which can turn into a pain in the ***..but sometimes there's just some things you have to do...

 

mine were so bad i broke them all, on the whole car except the passenger side front, thank god, or id have to pull the motor to get the old line off.

 

Oy. Well hopefully with a larger vice grip I can loosen the fitting. If not I get to learn about putting on new ends.

 

You shouldn't have to pull the engine. If worse comes to worse, cut off as much of the line as you can, and route a new line somewhere else, as long as it gets the fluid pressure to where it needs to be.