The rear disc brakes on a Peugeot 306 should be replaced every 60,000 miles or 6 years, whichever comes first.
These are general guidelines only, and the actual frequency with which you need to change your disc brakes will depend on a number of factors, including your driving habits and the conditions in which you drive.
If you drive in a lot of stop-and-go traffic, you will need to change your brake pads more often than if you drive mostly on the highway. If you live in an area with a lot of snow and ice, you will also need to change your brake pads more often.
