7.3 Inspecting Doubles and Triples

7.3 Inspecting Doubles and Triples

Use the seven-step inspection procedure 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 things to check. These are discussed below.

Additional Things to Check During a Walkaround Inspection
Do these checks in addition to those already listed in section 2, “Step 5: Do Walkaround Inspection.”

Coupling System Areas• Check fifth wheel (lower)
-Securely mounted to frame
-No missing, 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 safely latch/lock engaged
• Fifth Wheel (upper)
-Apron securely mounted to trailer frame, not bent, cracked or broken
-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 tractor frame will hit landing gear, or cab 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• Shut-off valves (at rear of trailers, in service and emergency lines):
-Rear of front trailers: OPEN
-Rear of last trailers: CLOSED
-Converter dolly air tank drain valve: CLOSED
• Be sure air lines are supported and glad hands are properly connected
• If spare tire is carried on converter gear (dolly), make sure it’s secured
• Be sure pintle-eye of dolly is in place in pintle hook of trailer(s)
• Make sure pintle hook is latched
• Safety chains should be secured to trailers(s)
• Be sure light cords are firmly in sockets on trailers

Do these checks in addition to section 5.3. “Inspecting Air Brake Systems.”

Safety First!