CDL PRE-TRIP INSPECTION
WHAT IS A TRUCK PRE-TRIP INSPECTION
|Commercial Drivers License
In essence, a driver will do a thorough check
[inspection] of their tractor, semi-trailer, and load, if
any. This inspection will become an integral part of a
truck-driver's daily job duties to ensure the safety of
the driver and the motoring public. Drivers, by law,
must perform a pre-trip inspection before the start of a
driving shift and once every 24 hours. In addition, a
driver should perform a pre-trip inspection each time a
new trailer is picked up and after every 10 hour break.
For those who perform team driving, its a good habit to
perform the PTI each time the drivers switch.
When preparing for the commercial drivers license, CDL, road exam, a student driver must
demonstrate to a licensed examiner a proficient understanding of the pre-trip inspection (PTI). This
means that the California Commercial Drivers Handbook stipulates the variety of systems and parts a
student driver will have to inspect. To better understand the Pre-Trip Inspection test, student drivers
should look at the PTI as two (2) separate oral exams: The Walk-Around Inspection and the Air
Brake Inspection Tests.
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The Walk-around Inspection, often referred to as the pre-trip, is only a portion of the full Pre-Trip
Inspection (PTI). The walk-around section of the PTI covers a variety of systems throughout the
tractor and trailer to ensure the truck is safe to operate on the road. For example, the driver will
inspect inside the truck (in-cab), all lights, different components of the engine compartment,
suspension system, brake system, and even ensure that the tractor is properly connected to the
trailer. If you are attending a trucking school (California), it is often not a good idea to refer to
Internet references on how to perform this portion of the PTI. Your truck driving school should have a
methodical method, study guides and material, along with sound instruction on how to learn/perform
The Air Brake Inspection, often referred to as the COLAS Test, is the portion that ensures a student
driver understands how to properly inspect the air-brake system for air leaks, faulty, or worn out
parts. Naturally, the braking system for a 80,000 lb vehicle will be an important part of the
inspection, and therefore, student drivers are not allowed to miss any points on this portion of the
PTI exam (yup, it must be perfect). Most, if not all heavy Commercial Motor Vehicles (CMV), utilize
an air-brake system, which is different from your personal vehicle's hydraulic brake system. On the
official Air-Brake Inspection portion of your PTI exam, you will have to perform five (5) pass or fail
tests. These tests will be performed inside the vehicle with a licensed examiner.
In the case of the COLAS acronym, each letter represents a test that a student driver will perform.
Here are the tests: Governor Cut-In Test (C), Governor Cut-Out Test (O), Low Air Warning Test (L),
Applied Leakage Test (A), Spring Pop-Out Test (S). Remember, your truck driving school should
have a methodical method, study guides and materials along with sound instruction on how to learn
the Air Brake Inspections.
If you are struggling and find yourself referencing online sources for your PTI, consider these three tips:
1. Keep to one source. There are different methods that may confuse a new driver
3. Reference your State's CDL manual for all PTI test inquiries
2. Make sure the source you are utilizing is from your State