Look on your state DMV website. They should have the Commercial Driver Handbook. There is a comprehensive pre-trip inspection in there; it is a required part of the test for Class-A and Class-B commercial drivers test.
Start at the hitch. these are not in any particular order, but I start at the hitch, and walk around till I get to the hitch again. I also look at like my EMT stuff, I am always looking for DCAP-BTLS(Deformities, Contusions, Abrasions, Penetrations, Burns, Tenderness, Lacerations, Swelling). While we check patients for many more things, we are constantly on the lookout for those things.
I look for: cracks, broken or failing welds, broken wire, dangling wires, broken or damaged lighting, missing parts, weather cracking, black widows, etc.
My list looks long, but it only takes a couple of minutes. I do this any time I trailer, new trailer or those that I have had for a long time. This goes for my flatbed, utility, and 5th wheel RV.
I check everything, even if I have a helper(son, Dad, friend) helping with the hookup.
- Before you hitch, check the ball. Is it the correct size, and weight rating(have seen a 2-5/16 hitch on a 2" ball towed over 1000 miles...)
- Hitch up
- Check that the hitch latch is properly latched
- Check that the hitch latch is locked(I use a Masterlock instead of the hairclip)
- Check your safety chains; are they crossed and secure?
- Check the brake-away cable; is it secure to the truck?
- You can check the break-away; pull the pin and try move the truck; the brakes should work on the trailer.
- Check the cable harness and connector; it it properly inserted in the receptacle on the truck, and free of any pinch point, not dragging
- Start down the left side of the trailer...
- Check the trailer jack; is it raised, and if applicable, in a locked position?
- Look at the wiring along the tongue; is it in good condition?
- As you walk around, you are looking at the frame of the trailer, above and below for cracks and broken welds.
- As you get to the left front, are the marker lights working, in good condition, and properly attached?
- Approaching the fender, is it properly attached and covering the wheels?
- Check the tires for wear and proper inflation
- Check lugnuts visually and verify they are torqued properly, and look for cracking of the rim around the lugs
- As you get to the left rear, are the marker lights working, in good condition, and properly attached? Look below to make sure the wiring is in good condition, and nothing is dangling below the trailer
- At the left rear corner, are the brake/tail lights working, in good condition, and properly attached? Are the wires secure, and not and dangling?
- While at the left rear corner, is the left ramp stowed correctly, and secured properly?
- Is the license plate on correctly, has correct tags, and illuminated correctly by tail light or separate light?
- Check and verify operation of any rear marker lights. Verify wiring is secure and not dangling
- Start up the right side...
- at the right rear corner, is the left ramp stowed correctly, and secured properly?
- At the right rear corner, are the brake/tail lights working, in good condition, and properly attached? Are the wires secure, and not and dangling?
- As you work up the right side, are the marker lights working, in good condition, and properly attached? Look below to make sure the wiring is in good condition, and nothing is dangling below the trailer
- Approaching the fender, is it properly attached and covering the wheels?
- Check the tires for wear and proper inflation
- Check lugnuts visually and verify they are torqued properly, and look for cracking of the rim around the lugs
- As you get to the right front, are the marker lights working, in good condition, and properly attached?
- Is the spare tire attached to its mount properly?(Mine is mounted on the right front of the trailer).
- Check the spare tire for wear, proper inflation, and check rim for any cracks, check around lug holes
- Check the jack, lug wrench, and chocks(the jack and lug wrench from your tow vehicle probably do not fit the trailer...)
- Check flares and/or warning triangles(safety markers in case you do break down)
- Now the trailer is verified, check you brakes and controller, per instructions included with your brake controller and/or trailer brake manufacturer.
- Double check everything after the first 25 miles. If new trailer, double check, especially lug nuts, at the manufacturer recommended mileage.
- Don't forget to do a similar walk-around on your tow vehicle.
Edit: I forgot...
- While checking the tires/rims on either side, look underneath at the spring, shackles, ubolts, and perches. Cracks, breaks, loose bolts/nuts, overall condition. You should also be able to see the wires to the brakes on the other side... Are they in good shape, not dangling etc
