Pre-trip ???

This. How I have always done it.

 

You can make up a tool. especially if you can find a cargo jack pad or somthing else flat and with the ability to put a rod into. you measure it out from the bottom of you seat to the pedal when it is down. I have one I made up, it is a piece of 1 inch square tubing, atached to a pad with a 7/8 rod in it and I welded a 1/2 nc nut onto the tubing, then drilled and tapped out the nut on the tubing and put a bolt in it.
I can adjust it to most any length and I also use it to hold down the clutch pedal.
I have seen them made with a rod, they used a couple of cummins push tubes welded together, and a 1/4x4 aluminum plate with a hole drilled thru it about 1/16 bigger than the tube, the plate binds on the rod holding it.
Considering the person in the tuxedo pants is looking for a reason to pull you over, it is a very good idea, to make something even a stick made the right length will work. or a couple of extensions and a socket to get the proper length.
Just a thought!

 

trolley valve

 

I use my tire thumper wedged against the driver's seat and the brake pedal to check the brake lights...

 

During daylight I hook a bungee cord on the trailer brake and the other side under the seat. At night just look for the reflection.

-Steven

 

This was my favorite answer , sounds like something I would say . Hahahah

 

I was waiting for you to say that the owner asked what the pigs tail had to do with trailer lights haha

 

Something as simple as a shoelace will hold the trolley valve open. then simply walk back and look.