Published: 11-May-2011

2007.0 Range Rover Sport (LS), 206-03

Front Disc Brake (G427409)

DESCRIPTION AND OPERATION
COMPONENT LOCATIONS - 4.4L and 2.7L DIESEL
E52024
 
ItemDescription
1Hub bearing assembly bolt (x 4)
2Caliper bolt (x 2)
3Wheel speed sensor
4Brake pad wear sensor lead
5Wheel speed sensor bolt
6Guide pin (x 2)
7Guide pin dust cover (x 2)
8Guide pin bolt (x 2)
9Caliper body
10Bleed screw dust cap
11Bleed screw
12Piston seal (x 2)
13Piston (x 2)
14Piston dust cover (x 2)
15Brake pad
16Brake pad retainers
17Caliper carrier
18Brake disc retaining bolt
19Brake disc
20Hub bearing assembly
21Dust shield screw (x 5)
22Dust shield
23Front knuckle
COMPONENT LOCATIONS - 4.2L
E52025
 
ItemDescription
1Wheel speed sensor
2Brake pad wear sensor lead
3Guide pin (x 2)
4Wheel speed sensor bolt
5Bleed screw dust cap (x 2)
6Bleed screw (x 2)
7Caliper clamping bolt (x 4)
8Damper weight
9Brake pad
10Brake pad retainer
11Caliper body half, inboard
12Piston (x 4)
13Piston dust cover (x 4)
14Piston seal (x 4)
15Caliper body half, outboard
16Brake disc retaining bolt
17Brake disc
18Hub bearing assembly
19Dust shield screw (x 5)
20Dust shield
21Front knuckle
22Hub bearing assembly bolt (x 4)
23Caliper retaining bolt (x 2)
GENERAL

The front brakes on all models feature ventilated brake discs, with different diameter brake discs for each model. The 4.4L and 2.7L diesel models feature twin piston sliding calipers. Although similar in appearance, the sliding calipers on 4.4L and 2.7L diesel are not interchangeable. On 4.2L models, 4 piston, opposed piston Brembo calipers are installed. The dust shields are common on 4.4L and 2.7L diesel models, and unique on 4.2L models.

Two steel damper weights are installed on the inboard side of the Brembo calipers to reduce noise, vibration and harshness (NVH).

On all models the brake caliper is attached to the rear of the front knuckle. 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, between the instrument cluster and ground. 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 amber light emitting diode (LED) in the brake warning indicator, displays an appropriate warning in the message center and sounds a warning chime. For additional information, refer to: Instrument Cluster (413-01 Instrument Cluster, Description and Operation).

At the beginning of each ignition cycle, the instrument cluster performs a bulb check on the brake warning indicator: the indicator is illuminated amber for 1.5 seconds, red for 1.5 seconds, then goes off.