What is the proper oil pressure line routing on a TO-30? October 24, 2015.
The female threads in the block are 1/8″ pipe thread. The fitting at the block should be a 90 degree fitting, 1/8″ male thread to 1/4″ female compression fitting. The original line is 1/4″ steel brake tubing with double flares.
The line is routed along the lock, up through the two legs of the air cleaner bracket along the side of the battery, making almost a 90 degree bend to connect to the oil gauge. The oil gauge should have an adapter fitting, 1/8″ female pipe thread to 1/4″ female compression to mate with the flare fitting on the brake line.