The short answer
Get your brakes checked the same day if you hear grinding, the pedal feels soft or sinks, the vehicle pulls to one side, or the handbrake does not hold. Squealing usually means it is time for an inspection soon.
What you might notice
Squealing
Often worn linings or dust. Book a check soon.
Grinding
Metal on metal. Stop driving and get it checked today.
Soft or sinking pedal
Air or a leak in the system. Do not carry passengers.
Pulling to one side
One brake working harder than the other, or a sticking part.
Test them every morning
Roll forward at walking pace and brake firmly. The vehicle should stop straight and the pedal should feel firm. Park on a slope and check the handbrake holds.
What makes brakes wear faster
✓Heavy loads and overloading
✓Stop-start town driving
✓Riding the brake down long hills instead of using a lower gear
✓Mud and water, especially in the rainy season
Worth knowing. Using a lower gear on long descents lets the engine slow the vehicle and stops the brakes overheating.
Getting them fixed
Brake parts are checked and adjusted at every service. If you notice any of the signs above between services, do not wait.
Hearing a noise? Describe it on the phone. Advice costs nothing.