| Author |
Message |
Dale MC8 (66.81.128.36)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 22, 2004 - 12:12 pm: | |
I have been reading these boards for quite some time and the question of air brake endorsement comes up regularly. My question is: why? This is not me being a wise guy, I really want to know. So far I have driven my bus very little, have read the California CDL booklet and don't see what the big deal is. Brake systems seem to me to be basicly the same. Step on the pedal to slow down or stop. What am I missing?
Dale MC8 |
Jim-Bob (12.46.52.74)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 22, 2004 - 3:02 pm: | |
I'm not in CA, I'm in FL and not to be a wise guy, but the CDL manual explains why it is different better than I could. Stopping distances, leaks, air brake lag, etc.
I have had my bus for 4 years & although I understand the systems very well, I went & got my Class B CDL (with passenger endorsement). I learned a very great deal and I know it has made me a safer, better operator of such a large vehicle. |
Nick Morris (Nick3751) (65.117.139.135)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 22, 2004 - 6:37 pm: | |
Dale,
I don't really think that just reading the book and getting your CDL's will gain you much either. However, I do think you will gain a great deal of knowledge of basic "large vehicle" operation and systems as well as getting a better understanding of what other drivers on the road with commercial rigs "see" so that we can all be safer on the road by taking a CDL class offered by a local tech school.
I had drive a small truck(3/4 ton) and horse trailer in 35 of the 50 states before I got out of college but still learned a lot about handling a truck and trailer as well as what the big rigs have to deal with on the road when I took my class in GA. The class I took also went into how to adjust your brakes, trouble shoot minor problems, and how and why the system works which will help you if you have any repairs to do.
I would highly recommed taking a CDL class and not just going to the driver license place and getting the piece of plastic. |
Tim Jones (Torquester) (12.73.177.201)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 22, 2004 - 11:29 pm: | |
Hi Dale,
I think that your question is a good one. I'm not too sure that an endorsement is really a necessary item, but the knowledge to be certain that your air brake system is functioning as it should is. You should also be aware that vehicles equipped with air brakes are usually heavy and require that the operator be aware of the physics associated with the weight.
Here are a few questions for you:
1. What happens to your stopping distance when your speed doubles ?
2. What is the maximum safe brake stroke for your vehicle ?
3. You are traveling down the road and you notice that the air pressure is at 60 psi. What should be happening in the cockpit ?
I feel that if you don't know the answers to these questions (these are just a few of many), you can not safely operate the vehicle.
HTH, Tim
p.s. answers....
1. it quadruples
2. varies with brake chamber size and type, you should know it for your application and check it.
3. you should be seeing and hearing warning devices that are alerting you to low air pressure as you are pulling off the road to stop. |
mel 4104 (208.181.100.58)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 23, 2004 - 10:50 am: | |
in Canada it is the law that if you operate a vehicleof any type ; truck, tractor, hd.eq., farm eq., etc. you must have an air brake endorsement on your lic. this means offroad included such as logging roads. the training course is very good and a great help to every one that uses air brakes. |
Ian Giffin (Admin) (64.228.43.94)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 23, 2004 - 12:16 pm: | |
For the vehicles listed, Mel4104 meant vehicles of any type that are equipped with air brakes, including obtaining at least a GZ license if you drive an air brake equipped bus conversion motorhome.
Ian
www.busnut.com |
Bob (Bobb) (69.19.4.131)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 23, 2004 - 12:34 pm: | |
and to add to Tims list above:
4. What are slack adjusters? Do they need adjustment?
5. How much slack should they have? What if I don't adjust them?
6. What is an s-cam? What happens if it no longer looks like an s?
7. When that air gauge says my pressure is dropping at a rather fast rate, what should I be thinking?
8. When the air pressure drops, should I blow the air horn, or save that pressure for a brake application?
9. Why do my wheels smoke, and the bus stops without me putting on the brake, just because I have no air pressure?
While air brakes and hydraulic brakes are common in that they both stop your vehicle, one needs more attention from you, the operator. Guess which one. You need to be able to do this maintainence with some authority, or you will be nothing more than a menace to the public around you when you are driving the bus. Hence, the need for an air brake endorsement.
I once saw a family burned alive by hot ashpalt while waiting for a ferry at the bottom of a long hill. Turns out the driver had no training in air brake maintenance. He did not check his brakes at the top of the hill. (actually didn't have a license at all)
His unstoppable dump truck full of hot ashpalt careened into the ferry terminal and came to an abrupt stop when it pushed the mini van the family was in, into the line of cars in front of them. Needless to say, the ashpalt didn't stop as quick. |
Tom Caffrey (Pvcces) (65.74.65.65)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 23, 2004 - 11:48 pm: | |
I notice many of the posts on this subject seem to be slanted towards the idea that air brakes are more dangerous or demanding than hydraulic brakes.
What's more dangerous or demanding is driving heavy equipment because too many people do not have a good handle on the energy that is stored up in these moving rigs.
For the most part, I think the air brakes are heavy duty brakes capable of stopping enormous loads when they are working properly.
If they don't work properly or if the driver doesn't understand the requirements of stopping a heavy rig, accidents can go far beyond the ordinary fender benders in cars.
End of rant.
Tom Caffrey PD4106-2576
Suncatcher |
Buswarrior (Buswarrior) (64.229.209.241)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 24, 2004 - 8:50 am: | |
Hello all.
The primary reason for the need to have some knowledge of how airbrakes work, is so one does not continue to drive the vehicle in blissful ignorance when there is something wrong with it.
Most drivers end up learning a whole bunch about brakes in general, since where would they have had any training in that before? Much of an airbrake class is "brake" class and can be useful for all the vehicles one drives.
Our cars have been made relatively idiot proof, and are expected to be in the scrap yard before they suffer some of the problems that our high mileage former commercial vehicles might have.
For instance: How often do cars suffer a brake line failure? Most commercial vehicles will see a change of hoses at some point in their useful life, and for sure in their non-profitable use as converted coaches.
There have been countless accidents that would have been prevented if the driver had known a little more about the brakes.
For instance: the brake stroke will need periodic adjustment, (and regular checking if equipped with auto slacks)
you, the driver, do not "push on the brake", you are only opening a valve, the air in the tanks is pushing on the brakes. No air, means no brakes, means you don't stop.
The low air warning is NOT a foolish irritant that can be ignored, required to be installed by an unknowing government. Just get out on the road, or I've got someone else here who wants to work...
You do not see how fast you can "make 'r go" down the mountain pass.
Can you imagine what weird things might happen if you just got in the seat and went, knowing nothing about how the braking system worked?
happy coaching!
buswarrior |
Jay Smith (198.81.26.45)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 24, 2004 - 9:42 am: | |
>you, the driver, do not "push on the brake", you >are only opening a valve, the air in the tanks >is pushing on the brakes. No air, means no >brakes, means you don't stop.
On my Thomas SafTliner, 'no air' means "all brakes", and that I'm not moving until I build up some air pressure. |
BrianMCI96A3 (69.68.205.231)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 24, 2004 - 6:03 pm: | |
Jay, while that might be true that you are not moving in your SafTliner if you lose air when you are stopped, that may not be the case if you lose air pressure on the far side of a mountain and your brakes were already begining to fade...
Brian |
mel 4104 (208.181.100.108)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, April 24, 2004 - 9:29 pm: | |
Jay the brakes on your SAftliner only come on the rear wheels, that is because youhave an air operated emergancy -park brake system. some vec. have a mechanical hand brake or foot pedal to apply the park brake and on this type of vec. if you loose the air you have no way to stop fast or even slow by the use of your brakes. |
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