[Richard and Rhonda]

Steve,

Ron is correct, those are DOT spec airline fittings. You can buy push to connecto fittings at Home Depot, but I wouldn't use them on the air brake system.

If you relieve ALL the air pressure, you can press the yellow collar into the fitting and the air line will release. Most times you will see that there is an indented ring on the nylon air tubing. If you have enough tubing to snip that 1/4 inch off, you can simply stick the new end back into the fitting and it should stop leaking.

If you don't have enough tubing to snip, then you have two options. Run a brand new piece of tubing. Of use a DOT spec compression fitting, the kind with the brass sleeve and nut that tightens. You'll have to remove the push to connect fitting and replace with the compression fitting.