Air leak behind panel

Not sure about that KW but I have replaced a few of those switches on my Freightliner. The usually start leaking around the post where the wires plug in.


You should be able to unplug the 2 wires and the sensor should just screw out with a wrench. At least that's how mine work.
Pump your air pressure down before you take it out.

 

Kinda hard to tell but it looks like a pressure switch.

 

Found a picture. This is what mine looks like once you get it out. $15 each. I have 5 or 6 in my truck, I carry a spare just in case.

Yours look different, but should screw out.

 

If it looks like a pressure switch wiggle the line going to it. The seal is probably worn out. Pretty reasonable repair not to hard to do

 

Sometimes the buttons on parking brake leaks, before they go bad. Try moving the buttons back and forth, up and down, after you push them in. Any difference in the leak, Parking brake valves on its way out. As far as the other leaks, welcome to my world. The quick connects on everything seem to go bad. Sometimes a fresh cut on the air lines, and re install, fixes it. Otherwise a perfectly good switch, for fifth wheel, or differential locks,dump valve, has to be replaced. Because of the quick connect. I’d like to do away with them. Thread a fitting into their place, add a compression fitting. Easier/ Quicker to just change the switches.

 

You do know you can change the oring in those quick connects?

 

I

had no idea. Thanks, have to check that out, I got plenty of o rings.

 

Pull the end of the quick connect out with some needle nose pliars. Take a dental pick (paper clip will work) and dig the oring out. Replace with a new one, put end back. I have had real good luck repairing them instead of replacing valve