Air Brake Simulation Errors [29002]

[dsevigny]

Actually the requirement would have it come on between 80 and 55 psi depending on the truck. At the school that I'm attending for my AZ (CDL) license, there are two trucks. The Freightliner Columbia I'm not sure of because I haven't played with it yet, but the Mack Vision comes on at 70 PSI.


We have a separate endorsement for air brakes in Ontario which requires that I perform a variety of checks to verify their correct functionality.

1. Mark and Measure. We do not have enough detail in the simulator to worry about this as we can't open the hood and the parts of the brakes aren't animated anyways. This is a good thing as it allows a wider range of computers to run the program. If each piece of the system was animated, and you could open the hood up and verify fluid levels, and part movement, most computers would choke and be unable to run the program.

2. Secure the vehicle. This is modeled in the sim by applying the parking breaks. In the cab, you can see the buttons extend to the out position.

3. Test the low-air warning device. This is modeled in the 1.4 beta. The horn sound is different for every truck and in some cases even by year, so I'm happy with how it was handled for the 1.4

4. Test the air-pressure build up time. Our standards here allow for 120 seconds to charge the tanks from 85-100 psi. In case of a compressor malfunction or weakness you'd see this. I don't usually get my trucks busted up enough to know if this is modeled or not.

5. Confirm the governor settings. There is a bug here. The governor should cut-in (or turn the compressor on) by 80 PSI. It appears to do so in the program. The governor should cut-out not below 100 and not above 135 psi (again by Ontario standards) and can vary from truck to truck. In the program the bug is that the compressor never turns off. It will pin the needle to 150 psi as that's the highest display but I don't think the governor is accurately modeled.

6. Test the air loss rate. You do this by applying and holding the brake pedal. Over a span of 1 minute you should see less than 4 psi lost, over 1 minute. Again I haven't verified this y damaging my truck enough.

7. Test the automatic application function of the trailer brakes (apply the RED BUTTON ONLY). In the program I have not figured out how to apply only the red button. I'm assuming the trailer brakes command is for the "spike".

8. Test the tractor protection valve. We can't do this until we have cable hookups modeled.

9. Test the spring brakes. Apply the parking brake and then try to pull forward. You shouldn't move.


So as of 1.4 the bugs that I've found all relate to only being able to operate both parking brake controls (they are one input as far as I know) and the compressor is always on. Neither of these is a major issue. It's just something to note if you are using the program to "drill" for your CDL training.

[room217au]

The compressor is always running. When the air pressure reaches maximum a valve opens and the compressor "free-pumps" until such time as the airpressure falls below a certain point. Usually from foot brake use, but other things (airhorns, gear shifts) use air. At least that's how it is with older trucks. Newer trucks have a 'blow-off' valve meaning the compressor is always filling the tanks but at regular intervals you hear a rush of air for a short period from the tanks when they reach max psi.
The retarder is your best friend

[PW4056]

Part of a pre-trip inspection is to verify the correct function and safety of a truck's braking system. Typically when you dump the air from the tanks (pump the brakes) there should be an audible warning above 60psi to accompany the visual warning (on the dash in most cases now). Many trucks will activate as high as 80psi. If you continue to dump the air, the spring brakes should activate between 20 and 45 psi. The buttons on the dash should automatically pop out. They do not do so.

Not a huge issue but it was something that I noticed. Maybe a future feature?

This was one that I had actually brought up to them way back in either February or March. In 1.4, they did add the warning. I'm not sure if they got around to getting the valves to pop out, as I haven't had time to really test it out.

We have a separate endorsement for air brakes in Ontario

That's the same here in the United States.

[dsevigny]

No. They have not gotten around to getting the buttons to pop below 45. Which is kind of too bad but w/e. It is not really a bug. It's just an un-added feature.

Side note.... Freightliner Columbia today... Low air warning, primary tank at 60 PSI. Go to release the parking brakes as I'm working on a different part of my pre-trip with my instructor and we decide not to worry about the low air warning as we aren't going to be moving the vehicle.... Buttons won't stay in, even at 60 PSI, as there isn't enough available pressure to cage the brakes.

[room217au]

I suspect in the game the buttons' animation is triggered only by the parking brake key. It's visual only.
I don't think it would be too much work to 'connect' the low-air-pressure trigger to the animation?

[PW4056]

No. They have not gotten around to getting the buttons to pop below 45. Which is kind of too bad but w/e. It is not really a bug. It's just an un-added feature.

What you have to understand is SCS is a European development team, so their experience is primarily with European trucks. Until I brought it up, they had no idea that it worked the way it did here in the United States. Apparently in Europe, when the air pressure gets that low, the brakes are electronically applied, hence if you tried to drive the truck whilst your air pressure was that low, you'd get the GPS pop-up telling you your air pressure was low. Obviously not the case with an American truck, and this was one they were supposed to get fixed, which they have not done yet, and I don't know when they're going to.

[Max]

rather than when is how as we need both functionalities. as such is more work and as its rather gimmick than game feature so it has lower priority. but have hope, its still on todo list and working the way up ...

[dsevigny]

Regardless of gimicky or not I successfully used the program to practice for my CDL. Big road here I come! Thanks SCS for a great app that only gets better over time!