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7.3 – Inspecting Doubles and Triples

Use the seven-step inspection procedure described in Section 2 to inspect your combination vehicle. There are more things to inspect on a combination vehicle than on a single vehicle. Many of these items are simply more of what you would find on a single vehicle. (For example, tires, wheels, lights, reflectors, etc.) However, there are also some new items to check. These are discussed below.

7.3.1 – Additional Checks

Perform these checks in addition to those already listed in "Section 2, Step 5: Do Walk-around Inspection."

Check fifth wheel (lower).

• Securely mounted to frame.
• No missing or damaged parts.
• Enough grease.
• No visible space between upper and lower fifth wheel.
• Locking jaws around the shank, not the head of kingpin.
• Release arm properly seated and safety latch/lock engaged.

Check fifth wheel (upper).

• Glide plate securely mounted to trailer frame.
• Kingpin not damaged.

Air and electric lines to trailer.

• Electrical cord firmly plugged in and secured.
• Air lines properly connected to glad hands, no air leaks, properly secured with enough slack for turns.
• All lines free from damage.

Sliding fifth wheel.

• Slide not damaged or parts missing.
• Properly greased.
• All locking pins present and locked in place.
• If air powered, no air leaks.
• Check that fifth wheel is not so far forward that the tractor frame will hit landing gear or cab will hit the trailer, during turns.

Landing Gear

• Fully raised, no missing parts, not bent or otherwise damaged.
• Crank handle in place and secured.
• If power operated, no air or hydraulic leaks.

Double and Triple Trailers