Power steering: With the engine running, check for excessive play by turning the steering wheel back and forth. Play should not exceed 10 degrees (or about 2 inches on a 20-inch wheel) before the front left wheel barely moves.
Trailer (if applicable): With the tractor parking brake released and the trailer parking brake engaged (combination vehicles only), check that the trailer parking brake will hold the vehicle by gently trying to pull forward with the trailer parking brake on.
Look for missing, shifted, cracked or broken leaf springs.
Look for broken or distorted coil springs.
If vehicle is equipped with torsion bars, torque arms or other types of suspension components, check that they are not damaged and are mounted securely.
Air ride suspension should be checked for damage and leaks.
When doing an air brake system leak check, how long do you hold the pedal and what do you check for?
Hold the pedal for one minute. Check the air gauge to see if the air pressure drops more than 3 pounds in one minute (single vehicle) or 4 pounds in one minute (combination vehicle)
Hold the pedal for 10 seconds. Check the air gauge to see if the air pressure drops more than 3 pounds in one minute (single vehicle) or 4 pounds in one minute (combination vehicle)
Hold the pedal for two minutes. Check the air gauge to see if the air pressure drops more than 1 pound in one minute (single vehicle) or 2 pounds in one minute (combination vehicle)
Hold the pedal for one minute. Check the air gauge to see if the air pressure drops more than 6 pounds in one minute (single vehicle) or 8 pounds in one minute (combination vehicle)
System Leak Check. With the air pressure built up to the governor cut-off (120-140 psi), shut off the engine, chock your wheels, (if necessary), release the tractor parking valve and trailer parking valve (combination vehicles), fully apply the foot brake and hold it for one minute. Check the air gauge to see if the air pressure drops more than 3 pounds in one minute (single vehicle) or 4 pounds in one minute (combination vehicle).
The The Pre-Trip Inspectin portion of the CDL Exam is required to obtain your CDL. During the pre-trip inspection, you must show that the vehicle is safe to drive. You may have to walk around the vehicle and point to or touch each item and explain to the examiner what you are checking and why. You will NOT have to crawl under the hood or under the vehicle.
Drivers need to have knowledge of how the actual vehicle(s) that they are conducting the test in operate. The drivers need to be able to explain and demonstrate different checks for the examiner as requested.
Taking the CDL Pre-trip Inspection Test
Class A Pre-trip Inspection Test
If you are applying for a Class A CDL, you will be required to perform a pre-trip inspection in the vehicle you have brought with you for testing. The vehicle must be a combination vehicle, representative of the unit you will be driving and must meet the class weight requirements. If the vehicle is an air brake vehicle, you must first pass the air brake knowledge test. You also must have passed all applicable endorsement knowledge tests that pertain to the vehicle you bring in for testing. Your test will require an inspection of the areas of the vehicle as instructed by your CDL examiner.
Class B and C Pre-trip Inspection Test
If you are applying for a Class B or C CDL, you will be required to perform a pre-trip inspection in the vehicle you have brought with you for testing. The vehicle must be a straight truck, passenger bus or school bus, representative of the vehicle you will be driving and must meet the class weight requirements. If the vehicle is an air brake vehicle, you must first pass the air brake knowledge test. You also must have passed all applicable endorsement knowledge tests that pertain to the vehicle you bring in for testing. Your test will require an inspection of the areas of the vehicle as instructed by your CDL examiner.
TruckingTruth's Pre-Trip Inspection Study Guide
We have an excellent Pre-trip Inspection Study Guide which includes a complete pre-trip inspection with photos and descriptions, numerous pre-trip inspection videos, and a complete vehicle checklist.