Pre Trip In Cab Air Brake Test

My first question to tt. I start cdl class in 2 weeks, and have been studying my air brake test. Question is, how many actual air brake test are there?? I have seen 5 to 7 test. It's a little confusing. Second question, do the air brake test go in a set sequence as a standard, or do they jump them around? Hope this does not sound like stupid questions. Just trying to get everything down pat. Overall, i have the air brake procedures down. Thank you for any and all input.

Welcome to the forum Gary! Daniel B. has a great post called Pre-Trip Inspection - My Way! A must see! It has a section that explains in detail the air brake test.

Air Brake Test

There are three stages to an Air Brake Test

#1: Applied Pressure Test

#2: Warning Light and Buzzer

#3 Tractor/Trailer Protection Valve Pop Out

Applied Pressure Test-

Build the air pressure to governor cut out. Put the truck in the lowest gear. Then turn off the engine Immediately turn the engine back on. Push in both the tractor and trailer valves. (This will release the parking brakes.) Push and hold the Brake pedal fully. Allow the gauges to stabilize. Announce the gauges have stabilized and the Primary and Secondary PSI. With the Brakes fully pressed, you should not lose more than 4 PSI in one minute. Announce that you are listening for air leaks during that minute.

Announce:

This test was successful because I did not lose more than 4 PSI in this tractor trailer combination vehicle.

Warning Light and Buzzer Test-

Pump down on the Brake pedal until the warning light and buzzer comes on, at or before 60 PSI.

Announce:

This test was successful because my warning light and buzzer both came on at or before 60 PSI.

Tractor/Trailer Protection Valve Pop Out Test-

Pump down on the brake pedal until both the tractor and trailer protection valves pop out. They should both pop out between 40 and 20 PSI.

Announce:

This test was successful because my tractor and trailer valves popped out between 40 and 20 PSI.

Also take a look at our High Road Training Program for more information on air brakes and pre-trip inspections.

...please notice how many times anchorman said "announce." That was not by mistake, and giving specifics is crucial. You got this!

And oops...props to Daniel! also.

Anchorman forgot one, the static test.

First you run the engine until you hear the brakes pop off at their max pressure (usually around 120psi). Then you turn the engine off and turn the key to the on position. You should lose no more than 3 psi in one minute. (Static test)

Then you apply the brakes to approximately 90 psi on the brake application gauge if the vehicle has one, if not use about half pedal. You should lose no more than 4psi in one minute. (Application test)

Then you fan (pump) the brakes down until you get a warning buzzer/light as the pressure falls below 60 psi.

Then you continue to fan the brakes until the tractor protection knob pops out, between 20 and 45 psi.

Then you start the engine and in low gear gently pull against the spring brakes to verify they are engaged.

This is how I learned it anyway.

Phil

Welcome to the forum Gary! Daniel B. has a great post called Pre-Trip Inspection - My Way! A must see! It has a section that explains in detail the air brake test.

Air Brake Test

There are three stages to an Air Brake Test

#1: Applied Pressure Test

#2: Warning Light and Buzzer

#3 Tractor/Trailer Protection Valve Pop Out

Applied Pressure Test-

Build the air pressure to governor cut out. Put the truck in the lowest gear. Then turn off the engine Immediately turn the engine back on. Push in both the tractor and trailer valves. (This will release the parking brakes.) Push and hold the Brake pedal fully. Allow the gauges to stabilize. Announce the gauges have stabilized and the Primary and Secondary PSI. With the Brakes fully pressed, you should not lose more than 4 PSI in one minute. Announce that you are listening for air leaks during that minute.

Announce:

This test was successful because I did not lose more than 4 PSI in this tractor trailer combination vehicle.

Warning Light and Buzzer Test-

Pump down on the Brake pedal until the warning light and buzzer comes on, at or before 60 PSI.

Announce:

This test was successful because my warning light and buzzer both came on at or before 60 PSI.

Tractor/Trailer Protection Valve Pop Out Test-

Pump down on the brake pedal until both the tractor and trailer protection valves pop out. They should both pop out between 40 and 20 PSI.

Announce:

This test was successful because my tractor and trailer valves popped out between 40 and 20 PSI.

Also take a look at our High Road Training Program for more information on air brakes and pre-trip inspections.

Should the key be on and engine off for this test?

...please notice how many times anchorman said "announce."

Anchorman forgot one, the static test.

Just to be clear, the quote and links in my first post were a reference to a previous topic by Daniel B. I did not say or forget anything as stated in the quotes above. All credit goes to Daniel B. Thank you!

This is what t is in VA

put truck in gear turn off engine turn on the switch push in both tractor and trailer valves

Static Check - lose no more than 3 psi in 1 min

Applied Check - put full pressure on service brake and AFTER initial pressure loss (from putting pressure on brake) you cannot lose more than 4 psi in 1 minute

Low pressure warning light/ buzzer check - fan the breaks BEFORE you get below 60 psi the warning light and buzzer should activate

Spring brake check - continue to fan service brake until pressure is between 20 - 40 psi and the trailer and tractor ales should pop ot (both ca be at same time or trailer first NEVER the tractor valve first)

Air Compressor and Governor check - take truck out of gear then start the engine, raise the RPMs to 1500 once at 85 PSI you hve no more then 45 seconds to get to 100 psi, after 100psi keep RMS at 1500 until the govenor cuts the air compressor off it should be between 120 and 125 PSI

Trailer Brake Check - put truck n low gear and push in the tractor valve, slowly release the clutch until you feel the tractor pulling against the trailor brakes the push clutch back in and pull the tractor valve

Tractor brake check - push in the trailer valve and release clutch until you feel the tractor pull against the brakes push clutch back in.

Service Brake Check - push in both tractor and trailer release clutch until you start to roll the gently push the service brake and you should come to a controlled and straight stop.

Well that is how i have to do at DMV in the morning or i instantly fail. It must be done in that order exactly.

Welcome to the forum Gary! Daniel B. has a great post called Pre-Trip Inspection - My Way! A must see! It has a section that explains in detail the air brake test.

Air Brake Test

There are three stages to an Air Brake Test

#1: Applied Pressure Test

#2: Warning Light and Buzzer

#3 Tractor/Trailer Protection Valve Pop Out

Applied Pressure Test-

Build the air pressure to governor cut out. Put the truck in the lowest gear. Then turn off the engine Immediately turn the engine back on. Push in both the tractor and trailer valves. (This will release the parking brakes.) Push and hold the Brake pedal fully. Allow the gauges to stabilize. Announce the gauges have stabilized and the Primary and Secondary PSI. With the Brakes fully pressed, you should not lose more than 4 PSI in one minute. Announce that you are listening for air leaks during that minute.

Announce:

This test was successful because I did not lose more than 4 PSI in this tractor trailer combination vehicle.

Warning Light and Buzzer Test-

Pump down on the Brake pedal until the warning light and buzzer comes on, at or before 60 PSI.

Announce:

This test was successful because my warning light and buzzer both came on at or before 60 PSI.

Tractor/Trailer Protection Valve Pop Out Test-

Pump down on the brake pedal until both the tractor and trailer protection valves pop out. They should both pop out between 40 and 20 PSI.

Announce:

This test was successful because my tractor and trailer valves popped out between 40 and 20 PSI.

Also take a look at our High Road Training Program for more information on air brakes and pre-trip inspections.

Should the key be on and engine off for this test?

Yes.. There will be a time when you start the truck to build the pressure and the turn off the truck, good habit is to turn the key back to on so you can hear the low warning buzzer.. Read Daniels post that anchorman posted. It'll help you a ton.

Gary, there are no stupid questions! Never hesitate to ask about anything that's on your mind.

There are indeed a bunch of different tests you'll be doing and it's awesome that you're getting a head start on all of this. But rest assured the school is going to teach you everything you'll need to know to pass the CDL exam, including the air brake tests.

The most important thing you can do right now to prepare yourself for schooling is to go through our High Road Training Program. Here's how the program breaks down:

To Get Your CDL Permit:

• Rules & Regulations
• Driving Safely
• Transporting Cargo Safely
• Air Brakes
• Combination Vehicles
• Pre-Trip Inspection
• Driving Exam

To get your CDL endorsements which are optional but we highly recommend you get:

• Transporting Passengers
• Doubles And Triples
• Tankers
• Hazardous Materials

And two sections we've built ourselves with info you'll need for everyday life on the road but the manual doesn't really cover it:

• Logbook
• Weight & Balance

I would recommend going to the DMV and taking your CDL permit test and all of the endorsement tests before you even begin your schooling. That's what a lot of people do and it puts them way ahead of the rest of the class. You'll have a solid grasp on the classroom stuff so you'll be able to focus on learning the driving portion while everyone else is trying to cram the classroom materials at the same time.

So I wouldn't stress too much on the air brake procedures. Instead, get through as much of the High Road as you can. And also, read through our Truck Driver's Career Guide from beginning to end and follow all of the links you come across if you haven't already. You'll learn a ton about what to expect during your schooling and through the first few months on the road.