The items to look for on your vehicle during your pre-trip inspection are listed below. Visually check for and describe how you would check:

• Lights: All lights (e.g., high and low beam headlights, turn signals, clearance, identification) must be clean and working.
• Windshields: The windshield must be clear and undamaged.
• Mirrors: The mirrors must be secure, properly adjusted, and clean.
• Rims: The rims cannot be damaged or bent. There should be no welding repairs or rust trails to indicate a rim is loose on the wheel.
• Tires: Each tire at every axle must be properly inflated, have evenly worn tread, and have no cuts or other damage.
• Lug nuts: All lug nuts must be present, not loose, and have no cracks radiating from lug bolt holes.
• Brake linings: The linings (where visible) must not be dangerously thin. Check brake drums and linings for oil, grease, etc.
• Oil level, coolant level, and power steering fluids: All must be in the safe operating range.
• Belts: There should be no cracks.
• Hoses: Should not be worn or leaking.
• Fifth-wheel assembly:
  • Mounting bolts: Cannot be loose or missing.
  • Safety latch: Must be engaged, if equipped.
  • Locking jaws: Must be locked around the trailer kingpin.
  • Platform supporting the skid plate: Cannot be cracked or broken.
  • Release arm: Must be in the engaged position and locked in place.
  • Kingpin: Where visible, cannot be bent.
  • Apron: Where visible, cannot be bent, cracked, or broken.
  • No gap between the trailer and the skid plate.
  • Sliding fifth-wheel: If equipped, has no loose or missing parts in the mechanism, the locking pins are engaged, and the fifth-wheel is positioned properly so the towing vehicle clears the landing gear.
• Other coupling systems:
  • Pin/Ball/Coupler: Must be seated properly in the coupler and locked.
  • Equalizing arms: If equipped, must be attached and the chains must be tight.
  • Safety chains: Must be in an “X” pattern.
  • Breakaway switch: If equipped, must be connected to the first link of the safety chain.
  • Air connections: If equipped, must be in good condition and not leaking.
  • Electrical connections: Must be seated and locked in place.
  • Landing gear: If equipped, must be fully raised and have no missing parts. The handle must be secure and the support frame and landing pads cannot be damaged. Check for air or hydraulic leaks if power operated.
  • Frame of trailer: Must have no cracks or bends in longitudinal frame members or cross members.
• Doors and hinges: Must not be damaged and must open and close properly.
• Ties: If equipped with ties, straps, or binders they must be secured.
• Emergency equipment: Identify the location of three red reflective triangles and of the properly charged and rated fire extinguisher.
• Hydraulic brakes: Check them by pumping the brake pedal three times and then applying steady pressure for five seconds. The pedal should not move.
• Air brake system, if equipped – Demonstrate the following:
  • Air governor cut-out: with the engine running and the air gauge rising, demonstrate that the air pressure gauge will not rise above 130 pounds per square inch (psi) by allowing the gauge to rise to its maximum pressure.
  • Air governor cut-in: with the engine running and the air gauge static, demonstrate that the governor will cut-in no lower than 85 psi by depleting the air supply (pumping the brake pedal) to the point that the gauge will begin rising.
  • Air leakage: when the air pressure is in the compressor’s operating range (85-130 psi), shut off the engine and release all air-operated parking brakes. Press down on the brake pedal and when the gauge stabilizes, begin timing for one minute. A single vehicle should not lose more than 3 psi and a combination vehicle should not lose more than 4 psi from the stabilized air pressure reading in that minute.
  • Low air warning device: deplete the air supply by pumping the brake pedal and check that the low-air warning light, buzzer, or both engages between 55-75 psi.