You should not replace just one brake pad. Brake pads are always replaced in pairs on the same axle. Replacing only one pad creates safety and performance problems.
Why Not One Pad
Brake pads wear together on both sides of an axle. If you replace only one pad, the new pad will be thicker than the old one on the other side. This causes uneven braking. The side with the new pad grips harder, making the car pull to one side when you brake. In an emergency stop, this can be dangerous.
Both Sides of the Same Axle
Always replace brake pads on both the left and right sides of the same axle. If you are replacing the front pads, replace both front pads. If you are replacing the rear pads, replace both rear pads. This ensures balanced braking force on both wheels.
Front and Rear Are Separate
You can replace front pads without replacing rear pads. Front and rear brakes wear at different rates and are not related. Replacing front pads only is perfectly safe as long as the rear pads still have enough material.
What About the Rotors
If the rotor is worn, damaged, or warped, replace it together with the pads. Installing new pads on a damaged rotor causes poor braking performance and noise. Many shops recommend replacing rotors with every other pad change to maintain optimal braking.
