Will Water on Brake Discs Affect Braking Performance?
2 Answers
Generally, water on the brake discs will not significantly affect braking performance. The daily maintenance of brake discs is as follows: 1. Pay attention to protecting the brake discs when washing the car: Before washing the car, it is recommended to let the car cool down naturally first, and then proceed with the washing and maintenance. During daily braking, the brake discs generate a large amount of heat due to friction when the vehicle slows down, causing the temperature to rise significantly. If the car is washed at this time, the brake discs have not had time to cool down, and the cold water sprayed on them can cause the steel brake discs to warp or deform due to thermal expansion and contraction. In severe cases, cracks may even appear. 2. Minimize brake disc wear: Although brake discs wear out more slowly than brake pads, mechanics at most auto shops usually only recommend replacing the brake pads and brake fluid. However, after a certain mileage, the brake discs will also show signs of wear. If the surface of the brake discs becomes uneven or the thickness falls below the standard, it can seriously affect braking performance over time. 3. Avoid brake noise: Performance-grade brake pads are suitable for long-term use under extreme high-temperature conditions. Due to differences in material composition and usage conditions, a 'hissing' sound is normal. However, if a 'hissing' noise occurs in regular passenger vehicles, it should be taken seriously. Car owners should regularly clean the brake pads and discs to reduce the entry of foreign objects into the braking system and replace them with qualified brake pads.
With over a decade of driving experience, I can confirm that water on brake discs does affect braking performance. I remember one time after heavy rain, when I stepped on the brakes, the car glided much farther than usual, almost causing a rear-end collision. This happens because water forms a thin film between the brake disc and pads, reducing friction—much like how it's easy to slip when walking on ice. This is particularly common after rain or car washes, and if not careful, the braking distance can double. I've since developed the habit of gently tapping the brakes a few times after driving through water to generate friction heat and evaporate the moisture. During regular maintenance, it's also important to check if the brake system's drainage holes are blocked to prevent water accumulation. Safe driving is crucial—avoid sudden braking when the brakes are wet; instead, slow down in advance and maintain a safe distance.
