What Are the Reasons for Stiff Car Brakes?
2 Answers
Car brakes becoming stiff mainly due to the following reasons: 1. Brake pads thinning, poor quality of brake pads, foreign objects in the brake pads, or rust on the brake discs, etc. In general cases, pressing the brakes a few more times can alleviate the abnormal noise. 2. Increased pedal travel during braking. The main reasons for increased brake travel are air entering the brake system, insufficient brake fluid, possible leaks, or severe wear of the brake pads. 3. Braking deviation. Mainly caused by uneven wear of the brake pads or issues with the brake calipers. 4. Brakes becoming hard. Primarily due to a failure of the vacuum booster, resulting in no power assistance for the brakes, or caused by frequent braking. 5. Rebound when pressing the brakes. Mostly due to uneven surfaces of the brake discs or pads, or deformation of the wheel rims.
Recently, my old car also ran into the issue of stiff brakes. After some troubleshooting, I found out it was due to a leaking vacuum booster. This component is like the power source for the brakes—once it leaks, it can't help you press the brakes effectively, and you'll need to replace the seals or vacuum hose. Another time during inspection, I noticed the brake fluid hadn't been changed in two years, and moisture had mixed in, forming bubbles under high temperatures, causing the brakes to feel spongy or stiff. If you're tinkering with it yourself, remember to check by pressing the brake pedal a few times after turning off the engine. If the pedal gets harder with each press, it's likely a vacuum hose issue. Also, worn-out brake pads can make the pedal stiff, and that metal grinding noise is heartbreaking to hear. It's recommended to check the brake fluid condition every 20,000 kilometers—don't wait until you can't brake on the road to regret it.
