Why Do Car Brakes Squeak After Passing Over Wet Roads?

Have you ever heard a squeaking or grinding noise from the wheels when pressing the brake pedal after passing through a puddle or a road that has just been rained on? The condition of car brakes making noise on wet roads is indeed quite often experienced by drivers, especially during the rainy season. It's natural to be concerned, especially since brakes are a component that relates to safety.

The good news is that in many cases, this noise is not a sign of damage. However, there are also situations when the noise becomes a signal that the brakes need to be checked. Let's identify the causes, how to distinguish between normal and dangerous sounds, and the steps to address them.

Causes of Noisy Car Brakes on Wet Roads

The braking system works through friction between the brake pads and the disc (or drum). When water enters this system, the friction condition changes. Here are some of the most common causes:

1. Thin Layer of Water on the Brake Disc

After the wheels pass through a puddle, the surface of the brake disc is coated with water. When the brake pedal is pressed, the pads must first wipe away this layer of water before gripping the metal surface. This wiping process often produces hissing, squeaking, or fine friction sounds, which usually disappear after a few braking actions.

2. Thin Rust on the Brake Disc

Brake discs are generally made of cast iron, which can rust easily when exposed to water. After being exposed to rain or puddles, a thin layer of rust can appear in a short time, even within hours if the car is parked. When the brakes are applied, the pads scrape off the rust, producing a rough grinding sound. This thin rust will be completely worn away after the car is driven and the brakes are used several times.

3. Brake Dust and Dirt Mixed with Water

Wet roads carry sand, mud, and fine gravel. These particles can get lodged between the pads and the disc, mixing with the damp brake dust. The result is a squeaking or creaking sound that is heard every time the brake pedal is pressed. If the particles are trapped for too long, the disc surface can become scratched.

4. Pads and Discs in Cold and Damp Conditions

Brake pads work optimally at certain temperatures. When the component temperature drops due to water exposure, the pad material temporarily becomes harder, and its friction coefficient changes. As a result, the brakes feel slightly less responsive and make some noise during initial braking. Once the temperature returns to normal due to friction, this noise and the feeling of reduced responsiveness generally disappear. However, the material of the brake pads can also affect this condition, so ensure your car uses quality brake pads.

5. Water Inside the Drum on the Rear Brakes

In cars that use drum brakes on the rear wheels, water can enter and accumulate inside the drum. While still wet, the friction between the brake shoes and the drum feels rough and can produce different sounds or sensations until the water evaporates.

Normal or Not? Recognize the Differences

To avoid misjudgment, pay attention to the following comparisons:

It is generally still normal if:

• The noise only occurs shortly after passing through a puddle or heavy rain.
• The noise disappears on its own after pressing the brakes a few times.
• The brake pedal still feels normal, not deeper and not vibrating.

Be cautious if:

• A grinding noise or metal-on-metal sound continues to appear even when the road is dry.
• The brake pedal feels deeper, vibrates, or the car feels less responsive.
• A burning smell appears after braking.
• The brake warning light illuminates on the dashboard.

If these second symptoms occur, it is likely that the brake pads are worn out. Learn more about signs of worn brake pads so you can take action before damage spreads to the brake disc and other components.

How to Address Noisy Brakes After Passing Wet Roads

You can take the following simple steps to dry the brakes and reduce the noise:

1. Lightly press the brakes a few times. After exiting the puddle, gently press the brake pedal repeatedly for a few seconds at low speed. This friction helps evaporate the water and clean the surface of the disc.
2. Reduce speed and maintain distance. While the brakes are not completely dry, their braking power may be slightly reduced. Increase the distance from the vehicle in front.
3. Avoid sudden braking. Hard braking in wet conditions makes the wheels more prone to slipping and puts more load on the pads.
4. Do not drive through puddles after prolonged braking. Hot discs suddenly exposed to cold water risk experiencing extreme temperature changes that are not good for the components.
5. Clean the undercarriage and wheels. Wash the car after passing through muddy or flooded roads to prevent sand and dirt from accumulating in the brake area.

When to Have Your Brakes Checked at a Workshop?

Immediately have your brakes checked at an official workshop if the noise does not go away after driving on dry roads, if the sound resembles metal grinding, or if the brake pedal feels different. Delaying inspection can cause the brake disc to become scratched and extend the braking distance, increasing the risk of accidents.

Ensure Safe Driving with Daihatsu

Noisy car brakes on wet roads are often just a temporary reaction to water, thin rust, or dirt, and will disappear on their own. However, you still need to be sensitive to changes in sound and feel of the brake pedal, as brakes are key to your and your family's safety on the road, especially during the rainy season.

Trust the inspection of your car's brakes to experienced technicians at an official Daihatsu workshop. Visit daihatsu.co.id now for information on regular service and keep your brake performance optimal on every journey.