What do you use the trolley valve for?

I'm putting every gauge I can fit into the dash of my W900A when I start piecing the cab back together. Its not a truck without 20 gauges in the dash lol.

 

You know those timid 4-wheelers that come up to pass but instead hang out next to the trailer tires?
A couple of quick pulls of the trolley valve to produce some tire squealing and smoke will get them moving again.

 

Light a few small fire crackers, and toss them out the window. Not saying that I would do it, but an educated guess is the Craptastic driver that pulls alongside you, then matches your speed, would suddenly drop back.

 

Yeah, I'm sure you wouldn't...

 

Check for air leaks downstream of the relay valves in the trailer brakes.

 

Tailgaters as long as it’s not my trailer…

also I am going to show my age here but the blue valve was for the service brake side

 

And don't forget about the wigwag dropping down.

 

Those were actually kinda cool!

 

Service “blue” has an extra tang off to the side to not allow it to couple onto the emergency “red side”.
The universals do not have the tangs.