| To verify they meet pressure requirements | |
| To release oil and water buildup | |
| So they can be inspected | |
| To check for leaks |
| Immediately fail | |
| Cannot be used | |
| Can be used indefinitely | |
| Can still be used several times |
| Air brakes | |
| Cab brakes | |
| Trailer brakes | |
| Emergency and parking brakes |