What are these hoses?

What are these silver and black air hoses? Lots of air is coming when I apply the brakes. Dont know if it is relevant but I just replaced the tractor protection valve. The reason for that being that air was coming out of the blue trailer hose, causing a honking noise, and the consensus in a truckers forum on Facebook was that the TPV needed to be replaced, so I did that. Before that I had a mechanic replace a fan actuator valve.

 

Dropbox - Hoses.JPG - Simplify your life

There is the photo again. The forum function to insert image did not seem to work.

 

I would start with tracing those lines to there source.
Does it change with the parking brake set. Truck parking brakes released and or trailer parking brakes released?

 

They just appear to be exhaust hoses for some of the valves. Probably have a bad valve somewhere.

 

Thanks! The gray goes to the dash valve. Regardless of the position of the dash valves, lots of air come through the gray hose when pressing the foot brake.

 

What truck?

 

I see DD15 fuel filters so most likely a Cascadia.

Need to see which holes in the manifold they come through so I can compare it to mine.

 

Looks like exhaust.

Anytime you have a back feed situation. Isolate truck from trailer. Identifying which unit is causing the issue. Start by pinching off brake chamber service lines one at a time. Brake chambers can backfeed from Parkside to Service with no audible air leak. This is completely free diagnostics.

 

@jamespmack has your starting point

 

2011 Freightliner Cascadia sleeper.