leader line check valve???

On the leader hose do you screw the check valve side into the compressor or into the tank side? Thanks for the help.~Jon~

Which ever floats your boat... as long it is installed to flow the proper direction, otherwise you could damage the compressor. Traditionally, it is placed at the end of the leader hose, however I know many off roaders that run Engine driven comps that run 'em a few feet off the comp into a tee with the pressure switch, then run a line to the tank from there.