Show greater stopping power when lightly loaded | |
Show greater stopping power in bad weather | |
Operate poorly when under load | |
Vary with |
When air pressure is at its maximum | |
During routine operation | |
While parked | |
During emergencies |
Apply the spring and air brakes together | |
Apply the air brakes gradually | |
Apply the spring brakes gradually | |
Switch between spring and air brakes |