Do pranksters/jerks actually pull the pin when the trucker isn't looking?

Yes it happens. JB Hunt had a big problem with that a few years ago.

When your truck has been unattended or you've been sleeping. Always check the fifth wheel before moving the truck. I visually check it and then put the truck in reverse and back against the kingpin to ensure I'm good to go.

 

Why visually check it if you go in reverse and back against it, anyways?

 

Thats the oldest way in the world for somebody to get even for anything you done to aggravate them whether you were aware you did or not. Pretty chicken you know but they do it. Im sure some do it cause its funny but how could maybe getting somebody fired be funny. I'm sure the first time it won't but if you have had any bad luck well maybe.

 

Don't really have to, that's just my own personal policy. Maybe overkill.
I usually kick the tires and check the lights anyway, so I look at the fifth wheel lock also. Pulling tankers I'm looking for leaks at the rear of the trailer before hitting the highway.

 

Yup.

Seen my neighbor at a rest area drop his trailer at a rest area pulled out so far before taking notice.

Got lucky it didn't tip or lean on me.
Would a been po'd

If I were a trainer I would do it to my student after dollying down....maybe a teammate if they could handle the joke.

Never someone else. That'd be bush.

 

In winter I have visually looked at king pin but not backed against it. It had done some wintery mix nothing serious anyway pull out my drive the half mile of gravel road pavement its all cool. I get straight on pavement and go to pumping it up and I feel slip. Hit the brakes hard get a bad look from my wife, qhat was that about? I stopped anyway and rechecked it, pulled the trailer brake handle and tugged on it. It locked that time. I'm sure had I paid better attention I would have seen it. Honestly I thought I did and the jaws were touching, just not locked. So I look every time, bump against it in retreat, then lock the trailer and tug. Had I set the trailer brakes tighter than the tractor as I usually do it would have totaled my cow trailer. Somebody was looking out for me to even feel what I did and realize what it was.

 

My trainer taught me to check everytime but he also told me set trailer brakes then tug tractor forward to put pressure on king pin. That way fifth wheel won't release if someone tries to pull it.