How to Distinguish the Inner and Outer Sides of Brake Pads?
2 Answers
The inner side of the brake pad has a friction block, while the outer side does not. Here is some related information about brake pads: 1. Description: Brake pads are important components in a car's braking system and are also wear-and-tear parts that need regular replacement. 2. Function: When the driver presses the brake pedal, the vacuum booster provides assistance, helping the driver to press the pedal. After pressing the brake pedal, the master cylinder pushes the brake fluid to activate the wheel cylinders, which then push the brake pads to clamp the brake disc. 3. Precautions: Brake pads, brake discs, and brake fluid need to be replaced regularly. Many car owners overlook brake fluid during maintenance. Brake fluid is a liquid that easily absorbs moisture. If the moisture content in the brake fluid is too high, it can lead to reduced braking force and longer stopping distances. When the moisture content in the brake fluid reaches 3%, it should be replaced immediately.
Distinguishing the inner and outer brake pads is crucial. Installing them backwards will cause squeaking and unstable braking. Having changed pads five or six times myself, I've found the most straightforward method is to check the letter markings on the backplate. Many pads are stamped with 'IN' and 'OUT' or labeled 'L/R' for left/right sides—just match them to the caliper and you can't go wrong. Some designs are even more obvious, like inner pads having an anti-rattle shim or spring clip while the outer one is smooth. For older models without any markings, you'll need to check if the pad's curvature matches the brake disc—inner pads usually fit better against the axle side. When in doubt, compare the sides facing the caliper piston since it always pushes against the inner pad, making that backplate thicker. Never install them backwards, or you'll wear the disc unevenly and end up spending big on replacements—this isn't money you should try to save.
