I recently replaced the right front brake line on my '96 with a 72" prefabbed line (flares and fittings) from the auto parts store. Upon replacement, I had a very small leak at the fitting going into the proportional valve. I was able to get the fitting snugged down a little tighter and the leak had stopped. Two weeks later and the leak has reappeared at the same spot, but I cannot get the fitting any tighter without completely rounding it off with a line wrench. Any ideas why this fitting isn't sealing good in the bottom of the proportioning valve?

 

Is it leaking around the line or the threads? Could be the flare isn't thick enough to seal to the surface of the valve. DON"T tighten it any more. First I'd try putting some pipe tape on the fitting threads.

 

It's leaking around the line - not the threads. I need to take the fitting back off and inspect the flare and also inspect the seat in the valve but that's going to be tough to do without completely removing the valve which I really don't want to have to do.

 

If you didn't replace the valve the problem could be the flare or hopefully just some foreign matter in the valve seat. Maybe you can use a small mirror to check the valve seat. If need be I would think you'd be able to clean it somehow without removing it. If it's clean and if you have a flaring tool you may be able to touch up the existing flare. If not cut it and reflare.