Pre-Trip Question

So, I went to take the skills test to get my CDL. The instructor told me that I aced the pretrip with plenty of points, but I failed because of the air brake portion. However, he told me I got all of the test done for the airbrakes, I did not miss any. But I did it in an incorrect order, so I failed.

My question, should I have been failed because I did it out of order, even though I did not miss anything? I am looking for opinions.

Yes, on the in-cab air brake test the order is critical. The order must be right to pass.

Yes it's fair that you failed due to doing it out of order regardless if you knew all the steps. It's important to follow the air brakes test as explained. It's the only part of the pre-trip that needs to be done in a certain order, everything else you can really do it however you want.

Micah, are you attending a school?

If you think about what you're testing for on that test, then you'll realize why it has to be done in the proper order.

Well that is good to know. Does it matter if I check the service brake before or after the air brake check?

And should the order go as follows:

1. With the truck running, run the air brake pressure to 90psi, and let it rebuild to 120-140psi to test the governer. 2. Shut the truck off, fan the brake to 60psi to test the low air warning light 3. Fan the brakes to 20-40 psi to test that the spring brakes are working correctly and the knobs pop out

I am not attending school, a older gentleman at work has taken me under his wing. I suppose I do not know why the order matters, so I'd anyone would be so kind to explain, I'm just curious.

Would the correct be as follows?

1. Test the service/emergency brake 2. Leak test by holding brake with brakes released and losing no more than 4 psi 3. Truck running, fan air to 90psi and make sure the governor kicks on between 120-140psi 4. Truck off, fan brake to 60psi to test low air warning 5. Fan brakes to 20-40 psi to make sure spring brakes push the knows out

The way Arkansas required and the way Schneider taught us when I got there, they required us to do the service brake test last.

Texas we were taught the applied for 1 minute test with our watch timing it, no more than 4psi for combination vehicle or 3 for single, then the alarm/signal at 60psi, then the valve pop out test at 40psi, it had to be in that order and 3 different steps, then we had the park/ trailer brake test then the 5 mph service brake test

Here's the air brake order taught at Swift, who use the Third Party testing which is theoretically good for all started.

(Engine running, get air pressure to maximum (120-140).)

1. Check PARKING BRAKE, push red button in, try to move forward.

2. Check TRAILER BRAKE, pull out red button, push yellow button in, try to move forward.

3. Check SERVICE BRAKE, push in both brake buttons. In gear, move forward a bit, both hands on the wheel, slowly press brake pedal. Report that brakes stopped smoothly and did not pull to left or right.

(Engine running, build pressure to maximum, remember, no feet on the brake pedal! Manual transmission: stay in gear, clutch in. Turn engine off but turn key back to ignition on without starting the engine. (some students will not turn on the ignition - instant fail - or will re-start the engine - instant fail too.)

Be ready to time by a clock - your wrist watch or the examiner should help you with timing. Not using a clock is an instant fail.

4. Press and hold the brake pedal for 60 seconds. Maximum president lots is 4 psi for a combination vehicle or 3 osi for a single vehicle.

Low pressure warnings: begin to fan the brakes. Hint: pressing about once every 2-3 seconds is better than quick pump-pump-pumps.

5. Low pressure warning (dashboard lights and sound buzzing) around 60psi. Keep having the brakes.

6. No pressure automatic brake (both buttons pop out) at about 20psi.

Tests completed!

Thank you all for the replies! I did everything in order apparently, except I checked the governor after I did the low and no air test instead of checking the governor first. I suppose he said I also forgot to mention that the cutoff for the governor should be 120-140psi.

Can anyone explain why the order is so pertinent? I didn't go to CDL school and have not been able to find anything as of yet as to why.