I purchased a used 2003 Ford Taurus from a local dealer. The first time I hit the brakes on wet pavement it scared the devil out of me! The pedal bounced back and there was a loud noise coming from the front of the vehicle that sounded like a motorboat. What is wrong with my vehicle? It doesn't do it on dry pavement. Should I take it back to the dealer? Sharon from Dallas, TX
There is nothing wrong, Sharon, with your Ford Taurus. As a matter of fact, that's exactly how the system is supposed to operate. This car is equipped with ABS brakes. You can take it back to the dealer just to give you peace of mind, but I think you will find that nothing is wrong. Tom
This is a common concern so let's take a closer look at how ABS brakes work, to both enlighten you and put your fears to rest.
A Brief Explanation of How ABS Operates
ABS uses wheel speed sensors, a hydraulic control unit, and a computerized electronic control module, which is the brain of the system. When the brake pedal is applied, the electronic control module monitors the speed of the wheels through the wheel speed sensors. If the control module detects that one or more wheels are about to lock up, the module signals the hydraulic unit to control hydraulic pressure to that wheel(s). This varying of pressure is much like pumping the brake, only with the ABS system the wheel that is locking up (which creates a potential loss of control) is the only one being controlled, the rest of the wheels are free to roll. This maximizes vehicle steerability.
Why Does This Happen On Wet Pavement Only?
Wet pavement can cause one or more of the wheels to slip and lock up. The ABS system senses this action and is activated to stop it. There is no need for the system to operate on dry pavement unless the wheels are slipping when stopping, which can happen when we drive on a gravel-covered road or apply the brakes very aggressively.
If you have never driven a vehicle with ABS brakes you may notice some marked differences from vehicles with conventional braking systems. These are:
- When the pedal is applied and ABS is activated, the pedal may feel harder than usual. This condition is normal.
- The pedal may seem to ratchet or pulsate (vibrate) or there could be a combination of these sensations. This action is also normal.
- Finally, you may hear a noise that sounds like a motorboat engine. This sound is the hydraulic control unit operating; again, normal.
Remember two important things when driving a car with ABS brakes:
- Maintain the same safe stopping distance from the vehicle ahead as with conventional brakes. ABS will not make the vehicle "stop on a dime."
- Do not pump the brake. Just apply firm, constant pressure and let ABS do the work for you. You may feel – as noted above – a slight vibration or hear noise as the hydraulic control unit functions. Be ready to push the pedal further if it travels closer to the floor.
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