Replacing rear disc brakes
Rear brake discs wear, calipers seize and the pads bind. Trevor Cuthbert explains how to put it all right
Discs wear, calipers seize and pads bind. Here’s how to put it right
DISC brakes are found on the front axle of all coil sprung Land Rovers, and on the rear axle from around 1994 onwards. The calipers are hydraulically actuated – when you press the brake pedal with your foot, the brake master cylinder pressurises the fluid, which pushes the caliper pistons out to press the pads against the brake disc.
Disc brakes have superior performance over drum brakes and are generally considered to be easier to service and require less maintenance. However, they do need to be inspected as part of routine servicing to check for various issues that can arise with the system.
The brake discs can become damaged in several ways, including scarring, cracking, warping or excessive rusting. Scarring occurs when the brake pads are not changed before they reach the end of their service life and the pad’s steel backing plate meets the brake disc after the friction material has worn away. This metal-to-metal contact ruins the surface of the disc and is dangerous. Cracking is mostly limited to drilled discs, which are not fitted to Land Rovers as standard, where small cracks may develop around the edges of the holes due to the disc’s uneven rate of expansion in severe conditions.
Excessive rusting can occur when the Land Rover is not used for an extended period of time. The contact area of the disc is usually kept clean by the action of the pads, clearing the small amount of surface rust that accumulates when parked for relatively short periods of time. However, excessive rusting can damage the pads when the brakes are reactivated.
The main problems that can arise with brake calipers is that one or more of the pistons can become seized due to corrosion. This will cause uneven pad wear and reduced braking efficiency. It can also help promote rusting and warping issues.
Note the wheel bearings on this vehicle are of the later type with end float set by a spacer, and the hub held with a single stake nut.