1995 GMC Yukon Owner's Manual - Page 193

Braking Braking action involves perception time and reaction time. First, you have to decideto push on the brake pedal. That's perception time. Then you have to bring up your foot and do it. That'sreaction time. Average reaction time is about 314 of a second. But that's only an average. It might be less with one driver and as long as two or three seconds or more with another. Age, physical condition, alertness, coordination,and eyesight all play a part. So do alcohol, drugs and frustration. But even in 314 of a second, a vehicle moving at 60 mph (100 km1h) travels 66 feet (20 m). That could be a lot of distance in an emergency, so keeping enough space between your vehicle and others is important. And, of course, actual stopping distances vary greatly with the surface of the road (whether it's pavement or gravel); the condition of the road (wet, dry, icy); tire tread; and the condition of your brakes. Avoid needless heavy braking. Some people drive in spurts - heavy acceleration followed by heavy braking - rather than keeping pace with traffic. This is a mistake. Your brakes may not have time to cool between hard stops. Your brakes will wear out much faster if you do a lot of heavy braking. If you keep pace with the traffic and allow realistic following distances, you will eliminate a lot of unnecessary braking. That means better braking and longer brake life. If your engine ever stopswhile you're driving, brake normally but don't pump your brakes.If you do, the pedal may get harder to push down. If your engine stops, you will still have some power brake assist. But you will use it when you brake. Once the power assist is used up, it may take longer to stop and the brake pedal will be harder to push. Anfi-Lock Brakes (ABS) Your vehicle has an advanced electronicbraking system that can help you keep it under control. When you start your vehicle and begin to drive away, you may hear a momentary motor or clicking noise. This is the ABS system testing itself. 4-5