Vehicle Inspections Part 1 – In Cab Inspections

Vehicle Inspections Part 1 – In Cab Inspections

Here at Eclipse DOT, as many of you know, we conduct a ton of CDL tests and CDL training to ensure you and your drivers can safely and properly inspect a vehicle prior to driving it.

Something we spend a good chunk of time on when training is completing a vehicle inspection.

 A vehicle inspection is made up of several different areas.

When inspecting your vehicle, you look at the front of the truck/ tractor, the engine compartment, the side of the truck, the coupling connection, the trailer, the lights, and an in-cab inspection.

I know it sounds like a lot, but it really is so easy that our COO, Dan Greer, has found a way to do it all in less than 10 minutes.  

First things first, a couple of tips and tricks for completing your inspection before we dive in today’s portion of that inspection.


I know it seems silly, especially to a seasoned driver.

But we all make mistakes even after years on the job!

Heck, even Tom Brady still throws an interception from time to time!

Going slow eliminates room for error and allows you the time to ensure you inspect every aspect of your vehicle so you can be confident you are operating safely!

We like to do things in threes.

It is scientifically proven and backed by studies that when you associate a motor function and/ or a number a task, it is more easily cemented into your central cortex.

And that explains why, on the study sheet we like to use for training, we group items into threes…  And suggest that you put your fingers up 1,2,3 for every part you inspect.

Because a vehicle inspection is as easy as 1,2,3!

Today we are going to discuss the in-cab inspection.

This will cover what we are required to keep in the cab, what we inspect when we first get into our vehicle at the beginning of our day, and what the light inspection consists of.

First things first, when we first step into the vehicle, not just commercial rigs but all vehicles, what is the VERY first thing we look for?

The seatbelt.

You want to ensure that it is mounted and secured properly. Additionally, you will want to examine the seat belt itself and confirm there are no tears or abrasions in that seat belt that it is roadworthy and that it will save your life if the unimaginable happened.

The next thing you are going to verify is that you have the proper safety equipment in your cab.

You are going to be looking for a fire extinguisher that is mounted and charged.

You will ensure that there are three (3) reflector triangles and they are in good working condition

Lastly, you will want to ensure you have some spare fuses.

The next thing I like to check is the horns. Do they function properly? Are they mounted and secured? 

All of these items are essential, and you can be penalized for not having them readily available if you were to be “invited” to do a roadside inspection with an officer.

Moving forward, what is the next thing you look for during the in-cab inspection?

The keyword here is “look”.

I like to examine the glass of the vehicle – i.e., the windshield, the windows, the mirrors, etc.

Visibility is an absolute must. If you have a big crack in your windshield that has “spidered” its way across the glass, chances are you cannot see your surroundings well enough to operate the vehicle safely.

And to see out your windshield, it should be clean, right?

It’s a great idea to clean your windshield daily. I hate it when mine is splattered with bugs and I can’t see anything, especially at sunrise or sunset.  That’s why I clean it every morning.

Now you’ll inspect the windshield wipers and washers to make sure if someone hits you with some muddy water spray from a puddle or it starts raining cats and dogs while you are out on the road, you will still be able to keep that windshield clean!

The final item to inspect regarding your visibility is the heater/ defroster.

I would venture to say many of you reading this life in an area where winters get FREAKING’ COLD!

Let me ask you a question. What is the one thing I hate most about my truck in the wintertime?

I’ll give you a hint!

Imagine you’re running a few minutes late for work, the kids are late for school… And… you forgot to warm the car this morning!

Now, you aren’t 10 minutes late for work, you’re 20 minutes late for work! The kids went from being 5 minutes late to school to 15 minutes late to school!

Why do you ask?

Because you must defrost the windshield! You can’t drive safely staring through a cloudy sheet of ice!

We’ve all seen that car with a small part of the windshield cleared off.  You know what I’m talking about, it’s about 2” high and 6” wide.  Then the driver is crouching down so they can see out of that little hole they scraped clean.

Don’t be that person.

When conducting your in-cab inspection, you always want to make sure the heater and defroster functions of your climate control work properly.

Because we have all been in the car when you’re driving down the highway and your windshield starts to fog up, simply because temperature changes.

Do you know what else we might be looking for?

Bingo! Lights! A good deal of drivers operates at night.

There are lights in numerous places on our tractor and our trailer, so we need to be sure we check the lens condition and light function at every applicable point.

For the in-cab inspection, we are going to check the brightness of the dashboard lights, because we need to be able to see the readings of all our meters and gauges. Ensure the lens and lighting of your oil pressure gauge, your air pressure gauge, your voltameter, and your speedometer are all in good working condition, and that they are secured properly in the correct place.

Next, you want to look at the hazard lights and ensure they are functioning properly. Nobody wants a situation progressing from bad to worse because another roadway user couldn’t see you pulled off to the side of the road due to faulty hazards, causing a collision and endangering your life and the lives of others!

As we approach the completion of our in-cab inspection, there are still a few items we need to inspect/ test to complete this inspection properly and in its entirety.

We are going to complete a ‘safe start’.

What does this mean?

It means we start the vehicle in a way that ensures the safety of ourselves and our surroundings. We will depress the clutch, ensure the vehicle is in neutral start the engine, and then slowly release the clutch.

Have you ever got into someone else’s vehicle, or even your own, and depressed the clutch, started the car, released the clutch rapidly, and the vehicle violently jolted back and forth before stalling out?

I, personally, have almost sent the front end of a sports car through my mother’s garage door by not completing a safe start.

I know we can be in a hurry sometimes but being 2 minutes late because you chose to complete a safe start and follow procedure is way better than never getting where you are headed because you did not start the vehicle safely and are now stuck dealing with insurance, repairs, and, in my case, explaining to my mother why there was the front end of Porsche sticking into her garage door!

Don’t forget to check your ABS light to ensure that it comes and goes out as you turn the key on.

Then after your safe start check all of your gauges so you know that they are working properly.

Next, you are going to conduct brake tests, for obvious reasons (LOL).

First, you can do a “tug test”.

To do this, engage your tractor (truck) parking brake, and with the truck in first gear, let off slowly on the clutch until you can feel the brake engaging and holding your vehicle in place.

Do this with your tractor brake and your trailer brake.

You are going to complete a service brake test as well. For this you will release the parking brake, start moving forward at about 5 mph then press the service brake (foot pedal). 

You should come to a complete stop and the vehicle shouldn’t pull to one side or the other.

Does your vehicle have air brakes?

If so, then next you will conduct an airbrake inspection!

The first step is to test the compressor.

To be up to regulation, it needs to build air from 85-100 psi within 45 seconds at normal operating engine RPM.

Next, the compressor should cut out (Stop Building Air) around 125 psi.

The next step is to conduct a system leaks check.

To do this, turn the engine off and then turn the key back to the on position without starting the engine. 

Make sure you have plenty of air in your tanks.

Release all the parking brakes by pushing in both brake buttons.

After the initial drop in pressure, watch and listen to the air gauge on the instrument panel.

The first one is called a static pressure test. 

This is where you watch the pressure for one minute and make sure you don’t lose more than 2PSI for a straight truck (Class B), or 3PSI for a combination (truck / Tractor, Trailer combination rig, Class A).

Did your truck make the cut?


Next, you are going to press the brake pedal hold it down for 1 minute, and watch for air leaks on the gauge.

The goal here is to NOT lose more than 4 psi per minute for tractor/ trailer (Class A) rigs, & no more than 3 psi for straight trucks (Class B).

Make sure you have a stopwatch or a timer to ensure you wait out the entire minute and that you keep that pedal depressed for the entire minute time requirement.

Now, you are going to conduct the low alarm test.

For this, you will pump the brake pedal until the low alarm sounds. It should engage at approximately 60 psi.

If this alarm does not sound you might not have the key on.  In some trucks the alarm won’t sound unless the truck is running, so make sure you at least see the light comes on.  Then you can check the buzzer or audible alarm after you start the truck.

Continue bleeding the brakes (pressing the brake pedal) until the parking brakes set, or the brake buttons pop out. This should happen between 20 and 40 psi and if they don’t…

You guessed it…

You’ve got a problem and need to get it fixed. 

The next thing to do is start your truck and build the air back up.

If you have hydraulic brakes instead of the airbrake test you should conduct the hydraulic brake test.

Don’t stress, it’s super simple.

Pump the pedal 3 times and hold it for 5 seconds to make sure it doesn’t squish to the floor like you’re stepping on a plumb.

The other hydraulic brake test is for vehicles with electric boosters (not all trucks with hydraulic brakes have these).  You’ll know you have an electronic booster if you turn the key on press the brake pedal and hear an electric pump under the hood kick on.

If you have reached this point with no hang-ups or issues, then you have successfully completed your in-cab inspection and can move on with the remainder of your daily vehicle inspection.

Remember when doing this during your CDL skills test, be sure to talk about everything you do and touch everything you talk about! Your tester cannot read your mind!

Do you need some practice on your vehicle inspections?

Please email for more information on training options available to you!







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