TRACTOR PROTECTION VALVE

[MoresHeavyHaul]

HELLO
I HAVE A 2016 389 THE TRACTOR PROTECTION VALVE LEAKS THROUGH THE EXHAUST PORT WHEN THE TRAILER BREAK IS RELEAST, SERVICE BREAKS APLYED AND TRUCK BREAKS SET.
ANY IDEA WHATS GOING ON???

[Papa_Buck]

Do you mean... When you pull the valve to set the trailer breaks, it back purges through your cab valve?

If so, your trailer valve has gone bad..

You can check by simply setting your brakes and getting out fast enough to pull the glad hand off... If you hear / feel air moving from the trailer glad hand... bad valve.