Why 3mm Matters
Once brake pad material wears below 3mm, heat transfer to the backing plate increases sharply. This can cause brake fade, vibration, and accelerated rotor wear.
How to Check Pad Thickness
Visually inspect through the wheel spokes, or remove the wheel for an accurate measurement. Many pads have wear indicators that squeal when nearing replacement.
When to Replace Both Sides
Always replace pads on both sides of the same axle to maintain even braking force. Uneven pads can pull the vehicle to one side during braking.
Bonus Tip
After installing new pads, perform a proper bedding-in process to transfer a thin layer of friction material onto the rotors for smoother stops.