When should you test the stopping action of your service brakes?

Testing the stopping action of your service brakes should be done when moving at approximately 5 mph because this speed allows for a safe and controlled evaluation of how effectively the brakes respond without compromising safety or vehicle control. At this slower speed, you can gauge the braking performance without the risks associated with stopping at higher speeds.

Additionally, performing this test while in motion ensures that the brakes can effectively respond under conditions similar to those you would experience during normal driving. Testing the brakes when driving downhill would not be advisable, as the increased momentum can lead to a dangerous situation if the brakes do not function properly. Parking or being stationary does not provide an accurate representation of the brakes' performance under real driving conditions, as the test requires movement to assess the stopping power accurately.