Why replacing rotors and pads together is the better option

For most vehicle owners, spending money at the mechanics is a ‘grudge purchase’, especially with cost of living pressures biting, so at first glance the thought of replacing worn brake pads and rotors at once, may not appeal.

There are several good reasons why replacing these two braking components together makes sense through. Wear rates of both pads and rotors will largely depend on driving style, road conditions, how the vehicle is used and the quality of the parts fitted. As a general guide, pads could last between 50,000 and 100,000 kilometres, while the wear life of rotors can be longer, perhaps an extra 10,000 kilometres.

Why then wouldn’t you hold off replacing the rotors at a future service to save a few dollars? Here’s some food for thought.

Firstly, for the sake of safety, stretching out an extra few thousand kilometres from the rotors isn’t worth the risk; the rotor thickness or quality of the rotor surface may not hold up until the next service, meaning you could be driving with a less effective braking system.

Over time, grooves or scoring on the rotor surface, and Disc Thickness Variation (DVT), can result in a compromised surface, so fitting new pads to these older rotors will result in the pads wearing prematurely. Owners then have a situation where the upfront cost saving of not changing rotors for a while longer is negated by the likely need to replace pads sooner.

There’s also the likelihood that the owner will need to return to the workshop between scheduled vehicle services to get the job done, meaning inconvenience and downtime. In terms of efficiency, it’s going to be less intrusive to do both rotors and pads in the one visit.

Replacing rotors and pads together ensures the braking system is operating at its best and may even save vehicle owners money in the longer term.

What about rotor matching?
Rotor machining – where the surface is refinished to remove grooves and restore a smooth finish by removing a thin layer of metal with a lathe – used to be a more common practice. Now the higher cost of labour, especially if the rotors need to leave the workshop to a specialist service provider, compared to the relative cost effectiveness of new components, means that replacing the rotor with a new one is cheaper and more efficient.

For owners using high performance rotors that feature slots and dimples, while machining is still possible, the process will reduce the heat, gas and dirt and water-dissipating qualities of the rotors.

Mismatched components
Replacing brake pads and rotors at different times also increases the likelihood of having mismatched brake components fitted. There can be small differences between the braking components produced by different brands, and mixing these may lead to reduced braking performance, reliability and longevity issues compared to fitting components from a single manufacturer.

The driver should also consider how well individual brake parts will work together such as in the case of some components having previously been upgraded. Certain brake parts are designed to provide better day-to-day driving performance, while other parts may be geared for the racetrack or to provide heavy-duty stopping power for towing.

In the case of Bendix products, all have been designed, engineered and tested to function 100 per cent in unison with each other and safely within optimum system tolerances.

While receiving a bill from the mechanic covering both pad and rotor replacement might initially not be welcomed, their recommendation will likely save you money and time in the long run, and of course, keep you safer behind the wheel.

For optimal performance, it's also recommended to fit rotors and pads from the same manufacturer.