I ran into this on the cat forum and thought it might be of interest to those who have air brakes.


Air Brake System Pre-trip Check


1. Be on reasonably level ground. Block wheels so the coach can not move even with the parking brake off.

2. Start engine and run until full air pressure is reached. Listen for the dryer to purge (about 120 PSI).

3. Shut off the engine.

4. Release the parking brake by pushing in the yellow button (make sure you don't roll, and do NOT apply the brake pedal).

5. After the initial pressure drop, the system should not loose more than 2 PSI per minute.

6. Apply the brake pedal firmly (still with the parking brake OFF).

7. After the initial pressure drop, the system should not loose any more than 3 PSI per minute.

8. With the engine off and parking brake off, rapidly pump the brake pedal to bleed down the air supply. During this stage you should watch for the warning light and buzzer at about 60 PSI and then the yellow button (parking brake) should pop out at about 30 PSI.

9. Restart the engine and build up air pressure again. While building up pressure, check how long it takes for pressure to go from 85 to 100 PSI at “cruising RPM”. It should be less than 45 seconds.