Rick Johnson has enjoyed tremendous success in racing.
Earlier in his career, Rick was a champion motorcycle motocross racer.
Since moving to truck racing, Rick was named 1992 Rookie of the Year for the Mickey Thompson
Stadium Off-Road Racing Series.
And due to his Class 8 win in the Baja 500, 1993 score International Rookie of the Year
for Desert Racing.
Hi, I'm Rick Johnson.
This video isn't going to teach you how to be an off-road racing champion.
Rather, it's going to help you understand one of the latest technologies in safety,
four-wheel analog brakes.
I've asked a couple of friends of mine to join me.
Dave, Cindy, come on over.
Just like you, they've recently purchased a new GM truck and they want to learn more
about the new analog brake system on their vehicles.
Ready to get started?
Go ahead and get into your vehicle so you can experience the benefits of ABS for yourself.
We have some other ABS equipped vehicles for them to drive as well.
ABS uses wheel speed sensors, a hydraulic control unit, and a computer control module
to greatly reduce the possibility of skidding during hard braking.
ABS also lets the driver steer the vehicle to help you avoid an accident.
Before we look at how ABS works and what it can do, let's talk about what ABS doesn't
do.
Analog brakes do not necessarily make stopping distances shorter.
You need to maintain the same distance from the vehicle ahead as you do with conventional
brakes.
Also, you still need to firmly apply the same amount of pressure on the pedal in enough
time to stop the vehicle.
You must keep constant pressure on the pedal to accommodate any brake pedal travel that
may occur while ABS is working.
Now let's take a look at what analog brakes do for you.
In a hard braking situation without analog brakes, the wheels may skid, losing traction
between the tires and the road.
As you can see with analog brakes, wheel lockup is kept to a minimum.
Four-wheel analog brakes also improve steering control throughout the braking situation.
Since the front wheels don't lock up, traction with the road is maintained, helping the driver
to steer around any obstacles.
On the other hand, without ABS, the vehicle goes into a skid and directional control may
be lost until the driver lets up on the brakes and the wheels start to roll again.
You may also think analog brakes only work when you slam on the pedal.
That's not true.
Analog brakes will begin to work as soon as a wheel starts to skid, which can happen even
with a slight application of the brakes, especially if the road is slippery or bumpy.
Antilock brakes will activate on wet, rain-slick pavement, on roads that are snow covered,
or on ice, braking on gravel roads, sand covered roads, and other loose surfaces may also activate
the antilock brakes, as could braking while going over bumps and elevations such as railroad
tracks.
And even if the road surfaces dry smooth concrete, such as a highway, the antilock brakes will
activate if the brake application is hard enough.
So no matter what the road surface or driving conditions, you can be assured that your four-wheel
antilock brake system can help you get safer, more controlled stops.
But to maximize the effectiveness of this system, there are several things to remember.
With antilock, you should not pump the brakes.
Just apply constant, firm pressure to the brake pedal and let the antilock system do
the rest.
Also, like a conventional brake system, ABS is most effective when the tires are in good
operating condition with good tread and the correct tire pressure is maintained.
Like any vehicle, whether equipped with ABS or not, proper seat adjustment is important.
Position the seat so the driver's foot can be placed on the pedal with a moderate bend
in the knee.
Even when the pedal is fully depressed, the legs should still be able to push the pedal
further.
And for commercial applications, the load should be evenly distributed over the rear
axle for maximum effectiveness of the antilock brakes.
Now let's review some of what you may experience when the ABS is operating normally.
When the brake pedal is applied and the antilock brakes activate, the brake pedal may feel
hard.
It may also seem to ratchet or pulsate, or there could even be a combination of these
sensations.
Inferm constant pressure on the pedal and be ready to push it further if it travels
closer to the floor.
You may also hear a sound like this.
As I said earlier, this four-wheel antilock brake system, or four-wall for short, is one
of the most advanced braking systems on the market today.
You've probably asked yourself, how does it work and what makes it so sophisticated?
Let's take a look.
The antilock brake system consists of several major components.
Wheel sensors, a hydraulic control unit, and an electronic control unit, which is essentially
the brain of the system.
The system works like this.
When the brake pedal is applied, the electronic control unit monitors information from the
wheel speed sensors.
When the control unit detects that a wheel or wheels are about to lock, the module signals
the hydraulic control unit to reduce brake pressure to those wheels.
The system holds the wheels near lock while keeping the wheels rolling to help the driver
steer.
Sound pretty complicated?
It is.
However, you can be assured of proper operation due to the various self-checks that the system
goes through.
Some of them are noticeable, some are not.
The first self-check occurs when you turn the ignition key to the on position.
The antilock and brake warning lights will illuminate momentarily.
This is called a bulb check and is normal operation.
The next self-check occurs when the vehicle accelerates to approximately eight miles per
hour.
During this self-check, the antilock system may make a sound like this.
And if your foot is on the brake pedal, you may feel some vibration.
The antilock system goes through other self-checks while you are driving.
However, these checks are unnoticeable.
In addition to those self-checks, there are also indicators to let you know if there is
a problem and your antilock brake system needs servicing.
If the yellow antilock or red brake warning lights do not illuminate during the bulb check,
the warning light system requires servicing.
If the yellow antilock warning light does not go out after the bulb check or if it comes
on during vehicle operation, have your antilock brake system checked and serviced.
This is an indication that you do not have the benefit of ABS.
However, the conventional brake system is fully functional.
If the red brake warning light doesn't go out after the bulb check or illuminates during
vehicle operation, bring your vehicle to a stop and have the entire brake system serviced
immediately.
Welcome back.
So what did you think?
We covered an awful lot in a short period of time.
Can you tell me what you've learned about antilock brakes?
Well, one thing for sure, my new antilock brake system greatly reduces wheel lock, which
can help me to steer the vehicle.
The thing I learned that I didn't know is that antilock brakes can activate on many different
road surfaces.
Oh, and also that tire inflation and quality as well as proper seating position are just
as important with ABS as they are with a conventional brake system.
But you know, the most important thing I learned is that ABS gives me improved steering control
during hard braking, which can help me stay out of accidents.
That's absolutely right, Cindy.
Also keep in mind that sometimes the brake pedal may vibrate or pulsate.
As the ABS works, you may hear some sounds and noises that are all normal in antilock
brake system operation.
Well, as you can see, my friends learned a lot and I hope you have too.
GM's commitment to safety provides us with one of the most advanced braking systems on
the market today, four-wheel antilock brake system.
Ready for stops, controlled steering, peace of mind.