I am install a champion three core radiatior Started car to check for leaks. found trans line is leaking. i know on trans side that the treads are 1/2" -20 STRAIGHT THREAD.
but the line side i am not sure. is it possible that they are metric threads and if they are is there adapter avaliable. any help would be appreciated.

Thanks Ralph

 

The line is 5/16" tubing. The fittings are 5/16" inverted flare. That fitting happens to have ½"-20 threads. None of it is metric. Not sure why people specify fittings by the thread size these days, which can be highly ambiguous (after all, 2 different fitting sizes can, AND DO, have the same threads sometimes) rather than the fitting size, but w/e... what do I know about that. It's just common sense to specify by the fitting size which is UNABIGUOUSLY ACCURATE EVERY TIME, but common sense isn't as common as its name implies.

 

that being said do i need a adapter to install lines to radiator

 

Most radiators come with the proper fitting already installed since that's what virtually all cars have for lines.

Eeeeeezy enough to find out though. Look down into the fitting in the rad and see if it looks like an inverted flare. If so, go to a parts store and get a 5/16" inverted flare ANYTHING; adapter, stick of brake line, whatever, whatever is cheeeeeeeepest; and see if it fits. Odds are, it will.