Lessons in School Bus Air brakes

[MrWill1985]

I notice sometimes when a commercial vehicle is parked you can hear the sound of air releasing from the vehicle. Now days I learned that is from the air brakes. What is happening when the air brakes make a releasing sound when the vehicle is parked?

[DawnFoxworth]

Thanks, just what I was looking for! You will part of my success when I pass my air brakes test for school bus.

[OttovonEarth]

Whoa! Still making this system.. I thought the electronically controlled brakes have replaced this ancient system everywhere which is just a back-up system of the ECB.

The system has significant advantages over this old-school system the more axles a vehicle has, such as the brake blending (jakebrake+retarder+service brakes together), ABS works faster, The ESP wouldn't be even possible without it, no lag between the front- and rearmost axles, equal wearing with disc- or drum systems etc.

[paccioli1]

thanks very nice!

[theblacklincoln]

This is one amazing presentation. Very helpful to new drivers.

[JohnxWaynexGacy]

Air rushes through relays?

[CapitanBluebeard]

this was very helpful

[binlod]

very informative videos!!! tnks a lot!!!!

[RadioMaster08]

Very good information and detail.

[roadwolf2]

and if your emergency or "maxi" brakes come on your in for quite a quick stop as they dont come on slowly they actually come on quite quickly. this comes from the son of a truck driver whos been in an air loss situation a few times

[svalesphoto]

Do you have a video for a complete pre-trip inspection suitable for use to train new drivers for their CDL Skills Test?

[gtuani]

but this apply only to heavy motor vehicles right>?

[montyloree]

Good video.... thanks!!

[PokemonMasterSammy]

hmmmm... good video! however they didnt mention much about when the air pressure drops below 30-45 psi, systems with spring brakes will lock up on you while in motion unless you pull over

[hondarider100r]

ok how does the pressure from braking move the rod back out if there is already pressure in the chamber keeping the spring from moving ??

[adr1974tony]

@hondarider100r The brake booster has 2 separate halves. The rear section (Parking/emergency brakes) has spring force holding the brakes on and requires air from a spring brake valve to work against this spring to release the brakes. The front section (service/foot brakes) works in reverse and requires air to apply the brakes. This was not shown in this video. This air for the service brakes comes from your foot valve by driver demand. I hope this helps.

[websterv8]

@hondarider100r

The rod is cut in half. So when the spring is pushing down the rod, the half of the service brakes is pushed down as well. But when the half of the parking brake is pulled back by air pressure (in the rear chamber), applying the footbrake will pressurize the front chamber en push down the front part of the rod. The back half of the rod stays in place because the front half cannot pull on it due to the cut.

[HYPHYDUM408]

Superb video, 10/10. always wondered how the air brake system on vehicles worked.

[papollonia]

Very Informative.. Thank you

[XdragonxalliX]

This is a very inmformative video. Is there any way to get a copy of this for training school bus drivers. I am a driver trainer and a State Instructor for the State of Illinois.

[michaelheiland123654]

How old you must be to become a school bus driver?

[Allison4220]

@michaelheiland123654 You should be 21 years old depends on what state you are in.

[khettabi]

A very informative video for truck driving students like myself! Thank you.

[lawnside82]

wow!! i learned sooo much!!

[LEMR9]

Very nice presentation, good for drivers and new hire mechanics.

[STNMagazine]

We're glad to share this kind of info. All thanks to Jefferson County. Since our video service is relatively new, what kinds of videos would you like to see in the future?

[bullpricko]

Would you have videos that cover retarders? (it's not a joke). All I know is that they help prevent wear and tear on brake pads by slowing down the engine.

[STNMagazine]

will look into this and see if we have a video for you. thanks for watching.

[RattlingMurdock]

I have seen a short video here on youtube about the principle usage of the Telma Retarder.

[studpuppy69]

Go search for Jake brake.

[RattlingMurdock]

A Jake brake involves using the engine as stopping power, a retarder uses the drive train.

[studpuppy69]

Correct. But, retard = slow, jake brake slows the vehicle it is considered a retarder, although it is in an engine brake(jake brake). The transmission retarder, is just called a retarder. If someone is looking for a demo on a retarder, the jake you can hear it gives people a small understanding, the hydraulic retarder on a transmission you won't really hear it. He was just curious about retarders, jake brake is a good demonstration is what im saying.