Folck: The biggest misconception that they have is that the car [with ABS] is capable of stopping in a shorter distance. On slippery surfaces ABS is usually advantageous. In wet weather it is advantageous. But a few systems, even on dry asphalt, if you energize the ABS is takes longer to stop. Usually it doesn’t stop you faster and that’s the big misconception.

And the second biggest misconception is, somehow they think they’ll always have control of the car. Even with the best of antilock brake systems there can be irregularities in the road surface and the vehicle can go into a violent spin.

Sidebar: What are the most common complaints you hear regarding ABS?

Folck: The most common complaint I get is that the brake pedal is pulsating or vibrating. Motorists are not expecting this pedal pulsation. On the Delphi 6 (ABS system), the pedal doesn’t pulsate. On some systems, it pulsates so slightly you barely perceive it. And some systems pulsate a lot. The salespeople won’t take you out and demonstrate how the ABS works because they know a lot of people will object to the way the pedal feels.

Sidebar: An article I read seemed to support the idea that when they came out with ABS it was in a laboratory type of environment and they really didn’t look at the way it would behave, and how people would react to it, in real-life situations.

Folck: You want a good one? The domestic trucks and vans that use the Kelsey-Hayes rear-wheel ntilock brake system. In those systems, when the ABS activates, the brake pedal will go to the floor, and nobody expects it to go to the floor.

Sidebar: So when that happens people think there is something wrong with the brakes?

Folck: Yeah. On the Kelsey-Hayes rear-wheel system [RWAL] (1) the pedal will go to the floor and (2) the rear brakes stop working. And simultaneously, the driver will feel that the vehicle is accelerating. So the brake pedal is on the floor, they feel the vehicle’s accelerating and they "know" the brakes have failed. And that’s how the Kelsey-Hayes rear-wheel system works.

Sidebar: They’ll "know" in quotes that the brakes have failed?

Folck: Yeah, their heart is in their throat. I mean, the brake pedal has gone to the floor, the rear brakes are released and they "know" the brakes have failed. It’s an, "Oh my God? What do I do now?"

Sidebar: And it feels like it’s accelerating because –

Folck: It’s got the rear brakes released. You don’t have the usual deceleration rate. What’s happening is, instead of four brakes working, only the front two are working. So you feel a lessening of the deceleration.

Sidebar: Do you think drivers are generally mis-educated about ABS?

Folck: Absolutely. They really don’t understand how the brake pedal will behave.

Sidebar: And you feel that the reason they are not shown how the ABS works is because the potential customer would object to it?

Folck: Right. The objections by the customer – they’ll go look for another vehicle that doesn’t have an ABS where you don’t get the pedal pulsation or the pedal doesn’t go to the floor.

Sidebar: What are the most common failures with ABS that you have detected from your vehicle inspections?

Folck: Well, in the General Motors trucks and vans, the 4-wheel Kelsey-Hayes antilock brake system. The brake pedal is supposed to just pulsate a little bit and stay in position, but sometimes it goes to the floor.

Sidebar: What does that indicate when it goes to the floor?

Folck: That there is a failure in the ABS. They have a problem with their algorithm, and it won’t set a failure code in the Kelsey-Hayes 4-wheel. In laymen’s terms, an algorithm is a sequence of functions the computer is supposed to take. There are glitches in the algorithm, and GM has acknowledged the algorithm failures. (Eds. Note: See the article in the Money Section of USA Today, "GM: Computer glitch could affect brakes", 05/22/98.)

Sidebar: The Haynes Automotive Brake Manual says ABS is a failsafe system, that even if the ABS malfunctions, it will just revert back to the normal brakes.

Folck: Okay, yes, they’re supposed to work like that, and the vast majority of them do; but there’s always the problem children where the ABS will fail and the pedal will go to the floor.

Sidebar: What might a driver feel during an ABS malfunction?

Folck: Some sensations are: a high, hard brake pedal that won’t go down; pedal to the floor; heart jumps in the throat – you’re coasting when the ABS malfunctions. Sometimes you’re freefalling – no brakes at all.

Sidebar: Would you briefly describe the components of an antilock brake system?

Folck: The wheel speed sensor monitors the speed of the wheels; it’s a magnet. The ECU (electronic control unit) is the electronic brains – it monitors the signals coming in and decides which course of action to take and, if it’s malfunctioning, it might produce a fault code if it’s been programmed to monitor that function. The brake pressure modulator is the hydro-mechanical unit, the working mechanism of the apply and release of the pressure at the wheel – "the pumper".

Sidebar: How fast does an ABS pump?

Folck: Faster than a human being can.

Sidebar: Do you think ABS was designed with the typical driver response to a panic situation in mind?

Folck: No, driver education is badly needed. An ABS driver definitely needs to go to a high performance school and learn how to use them.

Sidebar: What do you think the future holds for ABS?

Folck: More standardizing of the industry, of the systems. Eventually the electrical glitches will be corrected. I think there will be a recall in the Kelsey-Hayes systems in GM trucks.