After releasing the parking brake, how can you tell whether the trailer emergency valve is working (air tank filled) ?
When uncoupling the supply line (red coupling head), the pistons of the trailer's brake cylinders go into braking position
If the supply and brake lines are coupled, the pistons of the trailer's brake cylinders go into braking position when the brake pedal is pressed
When the brake line is uncoupled (yellow coupling head), the pistons of the trailer's brake cylinders go into the braking position without pressing the brake pedal
Correct answer :a
Driving license test
