1996 Mercury Sable Owner's Manual - Page 231

Occasional brake squeal during light to moderate stops does not affect the function of the brake system and is normal. However, if the squeal becomes louder or more frequent, have your brakes inspected by your dealer or a qualified service technician. Anti-lock Brake System (ABS) (If equipped) If your vehicle is equipped with the anti-lock brake system (ABS), the wheels will not lock and slide when you press down hard on the brake pedal. The ABS automatically starts releasing and reapplying the front brakes independently and the rear brakes together whenever your vehicle's wheels start to lock. When this happens, you will feel the brake pedal pulsate. This is an indication that the ABS is working correctly and is normal. If the brake pedal is applied while the vehicle is driven over uneven road surfaces, the ABS may cycle and the driver may sense a pulsation in the brake pedal, accompanied by a slight up and down movement of the pedal height and a clicking sound. This may also happen when driving on an inclined surface such as a driveway while making a sharp turn. This is a normal condition. Each time you turn the ignition key to the ON position, the ABS will function through one test cycle. When this happens, the ABS light will come on for up to five seconds. If the light stays on longer than five seconds, shut off the engine and restart. If it remains on, it means the ABS is disabled and should be serviced immediately to restore the benefits of the anti-lock feature. Normal braking is not affected unless the red BRAKE system warning light is also lit. 204