I moving the trailer supply and brake lines on a l9000 from back of cab to back of the truck for a tag trailer. This valve is on the brake side goes in and comes out to the blue line? Still gonna use it but wasn't sure what it was.
Looks like a quick release valve, does it have an exhaust port on the bottom? Have someone operate the line apply and release and see if air comes out of it on release.
Yup.