Front Brakes

GENERAL
All models feature ventilated front disc brakes. The 4.4L models use the same twin piston sliding calipers and brake discs. The 4.2L models use 4 piston, opposed piston Brembo calipers and larger brake discs. The 4.2L models also have a mass damper attached to the top of each front suspension strut to improve NVH (noise, vibration and harshness) when braking.

On all models the brake caliper is attached to the rear of the hub. The brake pads are made from an asbestos free material. The inboard brake pad of the left front brake incorporates a wear sensor.

With the sliding calipers, when hydraulic pressure is supplied to the caliper, the pistons extend and force the inner pad against the brake disc. The caliper body reacts and slides on the guide pins to bring the outer pad into contact with the brake disc.

With the Brembo calipers, when hydraulic pressure is supplied to the caliper, the two pairs of opposed pistons extend in the caliper. The two pistons in each side of the caliper force their related brake pads against the brake disc.

The front brake pad wear sensor is connected in series with the rear brake pad wear sensor, in a circuit connected to the instrument cluster. When a brake pad incorporating a brake pad wear sensor is approximately 75% worn, the brake pad wear sensor goes open circuit. When the instrument cluster detects the open circuit, it illuminates the brake warning indicator (red), displays an appropriate warning in the message center and sounds a warning chime.

At the beginning of each ignition cycle, the instrument cluster performs a 2 second bulb check of the brake warning indicator. The indicator is illuminated amber for 1 second then red for 1 second.