How to Check the Thickness of Car Brake Pads?
3 Answers
There are several ways to check the thickness of car brake pads: 1. Directly observe the thickness of the brake pads: When the brake pads become very thin, braking performance will significantly decrease, affecting driving safety. Generally, new brake pads are about 1.5cm thick. When the brake pads wear down to only 0.5cm, the frequency of self-inspection should be increased. 2. The car's onboard computer will prompt for replacement after a certain period: Most car dashboards have a brake warning light. When the warning light comes on, it's time to check the brake pads. However, the warning light indicates that the brake pads have reached the replacement limit and must be inspected immediately. 3. Listen to the sound of the brake pads: Brake discs are mostly made of iron and can easily rust after prolonged parking, especially in rainy weather. At this time, stepping on the brakes may be accompanied by a hissing sound, which will disappear after driving for a while and applying the brakes a few times. However, if the situation does not improve after some time, the brake pads must be replaced immediately. 4. Observe the brake response and travel distance: When the brake pads become thin, the car's braking response will also become sluggish. We need to press the brake pedal deeper and harder to achieve the previous braking effect.
As a car enthusiast, I often check the brake pad thickness myself because it directly relates to driving safety. My method is to first park on a level surface and engage the handbrake for safety. Then, I look through the wheel hub gap into the brake disc area - if the gap is large enough, I can visually inspect it directly. When brake pads are new, the friction material is quite thick, around 10mm, and gradually wears thinner. I usually use a small mirror or my phone's camera with flash from below to observe clearly. The standard is that if the friction material wears down to below 3mm, replacement is mandatory, otherwise braking distance increases significantly and becomes more dangerous in rainy conditions. I recommend doing a quick check at least monthly, especially before long trips. Last time I neglected self-inspection and only replaced them when hearing squeaking sounds at 2mm thickness, which nearly caused an accident. During maintenance, I'll have mechanics confirm it too, but DIY checking is simple and cost-effective.
One of the keys to safe driving is maintaining proper brake pad thickness. I check when the vehicle is cold by turning the steering wheel to fully expose the wheels for inspection. Through the wheel hub gaps, observe the brake caliper area - new pads have thick, noticeable friction material that thins with wear, eventually exposing metal. Many vehicles have built-in wear indicators where metal contact creates noise to signal replacement. If visual assessment is difficult, I use finger measurement by comparing thickness with adjacent components; normal thickness shouldn't fall below 3mm. I perform monthly checks during car washes, tracking mileage to predict replacement intervals (typically every 20,000 km). Worn pads not only reduce braking efficiency and increase rear-end collision risks but also damage rotors. To ensure family travel safety, I always encourage household members to adopt this maintenance habit.
