Question:
One of the most easily over looked item(s) when doing a pretrip inspection is forgetting to look for a copy of the trailer registration and to check and see that a current DOT annual inspection has been done on the trailer.
While we are on this topic....be sure that your tractor is up to date on its annual inspection as well. It is so easy to forget about these things.
Only two things I know of are infinite. The universe and human stupidity, and I am not real sure about the universe.
Answer:
Amen Uturn.
Remember boys and girls, the minute your fifth wheel snaps onto the king pin and you leave the lot, DOT considers that trailer and any defects (paper or physical) YOURS.
Take the time to look. The butt you cover will be your own.
"We have met the enemy, and he is us." pogo

Answer:
It is often not only overlooked, but also left for the next driver, to deal with a defective trailer.
It only takes a few minutes out of the day to do a good Pre-Trip on all of your equipment. A pre-trip should always include your registration for your equipment. A few days ago I was pulled over by DOT, All of my paper work was in order, and I was not even inspected. Having your house in order will keep you from working for the DOT and keep your money in your pocket, where it belongs.
Check that registration, and if it is missing, take that trailer number, into shipping and receiving, and get there fax number. Call your company and tell them that the registration is missing. give them the fax number, and tell the clerk, that your expecting a fax. When you get it, take it out and match it to the plate, and restore it to the registration box. DOT requires all companies, to maintain all paper work on every peace of equipment they own, at the companies home office, and must make it available for inspection.
Catch you on the flip.

Answer:
Although I am not what you would consider a senior driver, I do inspect any trailer that I pick up. I already have had 2 incidinces with trailer problems left by other drivers.
I complete a thorough pretrip on all equipment prior to the start of the trip, and during driver changes I inspect all equipments and lights (walkaround). Some of these roads knock those lights out of their sockets or just break them.
Before hookup of trailers document ANY and ALL problems no matter how small, and let your dispacther know to CYA.
John

Answer:
If you're switching trailers alot (large carrier), you've got to take the time to do what has to be done even ,when you could get away with just ignoring it.
I suppose flat tires and lights are most common. No one wants to go through the hassle of fixing a tire on the road. But someone has to do it, and better you NOW - while you can still plan it in advance - than you or someone else LATER when it turns into a call-out emergency.
Pressure-up the trailer (push red button) before completing your inspection to check for hissing sound from a pressure leak.
Then apply trailer brake (trolly handle) to check for a can that leaks under hard service braking. It's surprising how many leak while braking, but you don't know unless you listen by appliying the trailer servic brake, or do a full pressure-loss test from the seat.

Answer:
Make sure the tandem pins are set, especially if you're hauling a preload from where the tandems are always slid back when it goes in a door.
The previous driver may have left the handle out for you.

Answer:
Anytime you latch onto a dropped trailer, better check EVERYTHING including cross members, frame rails, kingpin plate and the things mentioned above.
Few drivers will write up a defect on a trailer they are getting rid of.
The attitude is "it's not my problem now" or "I might get blamed for this."
Catch it before it catchs your wallet.

Answer:
Remembered one more thing, always check the bridge laws of the states you are going through, California comes to mind, and set your sliding tandems to the right lentgh. I have already had one prior bozo slide the tandems all the way back.
John

Answer:
I had to sit in a scale house because a trailer air lines were defective. It wasn't readily apparent and a quick look didn't catch it. The part that attaches to the air lines where the spring is that holds the line off the groound was wearing through. Always check the places where there is anything attached to the air lines. It can wear through the rubber lines and be barely noticeable.
"Life, Liberty and the Pursuit of all who threaten it"

Answer:
Stuffiu-
Good point. Those springs that hold the air line slack by the tandems frequently get stretched-out or become detached. Those lines must be secured with enough distance from the road so they won't get caught on any debris (gator) you may encounter.
I carry a bag of large cable-ties. You can use one to temporarily cinch that spring back up and gt those air lines a couple feet of the ground until a proper repair. It won't be good enough for a DOT inspection, but it may prevent something from catching on those line and yanking them off in the meantime -- which locks your trailer brakes and leaves those big long skid marks.....