Renewing brake discs

Ed Evans suspects a classic problem with his Range Rover Sport’s front brakes – and finds plenty more reasons to replace them

Ed Evans transforms the stopping power of his Range Rover Sport

REPLACING THE front disc brakes on Discovery 2, 3 and Range Rover P38 and Sport is a much simpler job than on the earlier beam-axled models, but the braking problems and their symptoms are similar, whichever Land Rover you drive. Later brake discs are easier to change because they are located onto the front of the hub, sliding over the wheel studs. They have a single locating screw, but are further held by the road wheel and wheel nuts. Early brake discs on beam-axled Land Rovers are bolted onto the back of the hub, so the complete hub needs to be removed to reach the discs’ multiple securing bolts.

In this feature we’ll also see what happens to all brake discs and pads after an extensive period of use.

My Range Rover Sport has always braked incredibly well. Under emergency braking it does exactly what it should – it stops dead, and quickly, with no skidding and, importantly, it stops in a straight line with no directional veering. That all suggests the brakes are working properly and are well balanced across the axles, with both sides exerting similar force. But a slight vibration developed in the steering

wheel when braking, noticeable only on dual carriageways when slowing from 70 mph into a roundabout.

There are several possible reasons for this, including abnormal tyre wear, suspension joint or bush wear, wheel balance, wear in the steering joints or loose components. But the fact that this slight vibration occurred only rarely, and only when braking, pointed towards a brake problem. On the other hand, perhaps a problem in one of those other areas was simply being exaggerated during braking, when much of the car’s mass is handled by the front wheels. The condition worsened until even during slow-speed gentle braking when steering vibration was absent I could feel the brake pedal pulsing. I dismissed the idea of an ABS problem because the pulse was only felt at around 10 mph. This was almost certainly a warped brake disc.

I booked the car in with Land Rover specialist, Kevin Chadwick (07779 081388), at his 4x4 country garage at Clapham in North Yorkshire to have a new set of front discs fitted, and to ascertain exactly what was causing the problem. The pictures initially show the left side front brake being replaced (which has the brake pad wear sensor), though it wasn’t until we tackled the right-hand side that the cause of the problem was confirmed.

Repair and maintenance should always be carried out equally to the brake on each side of the axle in order to maintain safe braking balance. This applies to new pads, discs, seals, calipers and guide pin repairs.