I personally swap out my brakes every 3-4 years. However, what works for me could be totally different for you. Bear in mind that for the brakes, this is actually two components; the brake pads and the brake discs. There are a few things that you need to consider.
The first is how much mileage you’re doing every year. On the face of it, you may feel that since you’re only doing a few thousand miles per year that you don’t need to swap out the brakes. However, one thing to bear in mind is that the structural integrity of the breaks will start to break down as the years go on. Therefore, even though you may not be doing a lot of miles on them, they’re no longer stable and will need replaced.
It could be the situation that you haven’t had a lot of miles out of the brakes, but they’re no longer as efficient as they once were due to their age.
There is a legal minimum tread depth that must be adhered to. In the UK this is 1.5mm but I always swap them out at 3mm. This is there for not only your safety, but also the safety of others. Once your brakes get down to this minimum level, it is time to replace them.
When the car is having it’s annual MOT and service, the garage will advise you on this. Also, depending on what your wheels are like, it may be possible to inspect the brake pads yourself. It can be tough to gauge the exact amount of friction material left on the brake pad, but you should be able to eyeball it and get a fairly good idea about it.
On some brake pads, they have a section added onto them so that when the pad starts to wear down past the acceptable level, you’ll be able to hear this every time you apply the brake. On newer cars, there are even sensors present on the brake system that will alert you when the time has come for them to be swapped out.
Generally speaking, when you notice that they are not as efficient anymore, or they are squeaking, that is a clear sign that it is time to replace your brakes.
Do I need to replace the discs as well as the brake pads at the same time?
The good news is that the brake discs/rotors generally last a lot longer than brake pads. Due to this, they do not need to be swapped out when the brake pads are replaced. The exception to this is when of course the disc thickness is below the legal minimum level. In addition to this, if there are large score marks, pitting, or corrosion on the brake discs, these should be replaced. The reason for this is that the surface of them has been compromised. As such, they will not be as efficient at stopping the vehicle, making it a safety hazard.
Do I need to swap out the brakes on both sides of the car at the same time?
The answer is yes. With pad and disc brakes, there are two pads attached to one disc and two attached to the other. All 4 are used in order to bring the car to a stable stop on that axle.
If it was the case that the pads were swapped out on the left hand side, but not on the right hand side, this would cause some issues.
The first is that the efficiency of the breaking system would be reduced. At the best of times, this can cause issues, but in the winter especially this can be extremely dangerous. It can mean that the car does not stop in time, thereby causing an accident.
Due to the lopsided breaking, this can also impact the suspension on the car. It will make the car pull to one side, thereby putting additional pressure on the components on that side of the car. This can result in steering issues if left to continue, which can also be an expensive fix.
Lastly, due to the car pulling to one side, it can also cause uneven wear on the tyres. The end result of this is that the tyres will need to be replaced sooner. This can also impact the gripping ability of the tyres on the road, making the situation unsafe. Due to this, it’s really important to swap the brake pads out in pairs!