| When more than one of the trailers you`re pulling has brakes | |
| When pulling more than two trailers | |
| Never | |
| When driving in snowy weather |
| To convert an axle into an additional fifth wheel | |
| To couple an axle and a fifth wheel | |
| To convert a fifth wheel into an additional axle | |
| To convert a fifth wheel into a dolly |
| Open the emergency line shut off on the rear trailer | |
| Open the service line shut off on the rear trailer | |
| Use a calibrated air pressure gauge | |
| Pull forward slowly then apply the brakes and watch for a drop in air tank psi |