Tool Box

Complete socket and wrench set, standard and metric. Screwdrivers of various sizes, straight & philip. Torx and allen set. Hammer, electrical tape, Crescent and vise-grips. Various spare hose clamps, light bulbs for headlights, turn signals and markers. Spare fuel filter in case you gel up during winter. Spare belts, tire gauge, wire ties, wire brush.

...just for starters

 

Along with the above list, I advise a 10 in 1 screwdriver (Klein). It's available at most Home Depot/Lowes in the electrical tools area. Unless I'm prying something, it's my driver of choice.

Also, don't forget channel locks, needle nose, knife, 100 ft soft tape measure and 25 ft stiff tape measure and Duct Tape.

 

In my oppinion it depends on your mechanical skills. Have you worked on big trucks before? Do you have basic mechanical ability?
I personaly carry a lot of tools but im not afraid to crawl under and wrench to get going again. Another thing is all the tools in the world cant get you going with out parts. Im not saying to carry the whole parts dept. with you but things like hose clamps, zip ties, electrical wire and wire conectors, lights, electrical tape, nuts and bolts, a couple gallons of pre mix antifreeze, a tube of rtv silicone, WD40, fuses, and an extra belt.
I think the basics are a good ball pein hammer, a good flash light, several screw drivers of both straigh and philips, vice grips, wire cutters, a razor knife, and a test light. Maby a cresent wrench also. Also check your truck for special fasteners like allen head or torx head bolts, especialy on the dash and other interior panels. Other things I carry to go with the tools are rags, hand cleaner and coveralls or and old jacket to keep your self clean.
I also carry 1/4", 3/8", and 1/2" sockets. Standard and metric, shallow, and deep. A complete combo. wrench set, standard and metric. Extension bars, allen and torx sockets. Allen wrenches, torx drivers. A hack saw, pipe wrench, pry bars, punches and chisles and several different pliers. A large cressent wrench and a 3lb hammer. I also carry never seize and a quart of 90W for the hubs.
The down side is it all weighs a little over 150lbs. and takes up a lot of room but I would be lost not having it. Its also my responsibility to maintain and to fix my truck so I use my tools a lot. If your not able or willing to do more technical repairs to your truck than you dont need all that I carry but I would still have the basics I listed above.
One very important thing to remember, If you are a company driver many companies dont want you to do any thing more then change a light. Its against company policy to work on the trucks. Before you spend to much money on tools be sure your company will let you use them.

 

I carry a cage bolt and a 3/4" box end wrench, in case I need to release an emergency brake with it...also a vise grip to clamp an air hose off if there is an air leak.

Not all mechanics leave the cage bolt on the brake chamber where it is supposed to be, instead of in their tool box, where it does you no good.

Air lines and brakes are two of the most common problems that will get you stranded along the roadside.

Also, a micro-torch to thaw frozen brakes this winter, if needed.

 

A very short mechanic.

 

Wow, covered that well, only thing I'd add is extra glad hand seals. Only a coupla bucks, but when you go pick up that drop trailer and the last driver left it with a bad seal or worse, no #### seal, you can pop one in... otherwise you're runnin to the truckstop for a $2 part. Oh and a lil bit of wire (not sure if that was said?) for those missing door ties/chains. Real PITA when you can't tie your doors back. Oh and stock up on a few bunjee cords and tarp straps. You gotta have trailer air lines 18" off the ground, so if you slide tandems forward, they might drop low and can be a quite invite into the scalehouse. Strap 'em up. You also can't have your air lines touching the catwalk. Not a prob if you have the plastic ones, but if you have the others, you might want to strap them up a bit. Just don't do it too tight or you'll rip a gladhand off on a hard turn. I'm sure someone above mentioned a hammer, probably more than one kind, but you're going to need something (hammer, crow bar) to break frozen brakes. Good luck!!!