Brakes potentially getting wet just a fact of life. Unless you only drive your car indoors, you don’t have a choice but to drive through the rain when the weather gets wet – and this means driving through water whether you like it or not.
So, can brakes get wet? Yes, they absolutely can, and it’s generally not a problem, especially with most modern cars. Getting wet brakes while you’re driving can typically be resolved with some light braking, though it often isn’t something that needs to be “solved” at all.
There may be some misinformation about the severity of getting wet brakes, and this is most likely from issues experienced by cars from earlier years, which were more likely to have different types of brakes.
Different Types of Wet Brakes
To understand what situations are and aren’t problems, it helps to know the differences between the two most common types of brakes: disc brakes and drum brakes.
Drum brakes have two braking pads that press on the inside of a drum or cylinder that rotates with your wheel. The important thing to remember when talking about wet brakes is that these brakes are on the inside of a container.
Drum brakes were commonly used in the front and back of older vehicles. They can still be found in less expensive modern vehicles, but typically only for the back wheels, while disc brakes will be used in the front.
Disc brakes have a rotor (or disc) that rotates with your wheel, and is stopped by two brake pads that squeeze the disc to slow down your car. These are the most common brakes, which you can see on the majority of modern cars – especially in the front.
These two types of brakes, unfortunately, respond differently to wet environments. When drum brakes get wet, water can sometimes get trapped on the inside of the drum. While the drum is spinning, the water will spin on the inside and work its way between the brake pads.
This will decrease the car’s braking ability for a few seconds, until the water is released. This is why anyone who had spent more of their time driving older cars may advise you to use your brakes for a few seconds after driving through a puddle.
When disc brakes get wet, the water isn’t trapped inside of a rotating container, and can easily fall away from the brakes. This is why braking for a few seconds after driving through a sizable puddle is less necessary with newer cars.
But wait! We did say that drum brakes are still commonly used in the back of modern vehicles, right? This is true, but the majority of your braking power comes from the front of the car (the disc brakes).
So what’s the verdict? If you have an older vehicle with drum brakes on the front and rear wheels, it is always wise to test the brakes for a few seconds after driving through any considerable puddle on the ground.
If you have a modern vehicle, you have much less to worry about, but some light braking won’t hurt, if you choose to do it. You do, however, need to take care to avoid driving though extremely large puddles, especially if you don’t know how deep they are.
While this still shouldn’t cause any significant issues with disc brakes, your car could take a nasty hit if the water is deeper than you think, and there’s a hidden pothole or heavy object under the surface.
In dry weather, there’s no need to worry about these things, but slipping brakes in this weather could indicate a much more serious issue, like worn down brake pads or leaking brake fluid, so take any slippage seriously in that regard.
Rusty Rotors
Don’t be surprised when your rotors (metal exposed to abundant water and air) get rusty. This can happen in a short amount of time and is generally nothing to worry about.
The majority of rotors used by the average consumer are made from cast iron, but the exposure of the brake pads and rotors on most cars is actually a good thing, as this allows the owner to monitor the surfaces and find any visible issues.
Brake pads, when being used, will constantly wear at the the rotor surfaces. This means that every time you stop and park your car, the exposed surface is almost completely new and at the mercy of the weather. Cast iron will rust quite quickly in this situation.
This won’t take long – more than a few hours, but definitely less than a day. However, this only forms on the surface boundary of the recently used rotors. This is called surface rust.
Fortunately, this isn’t a problem. It happens all the time to almost all rotors, excluding the ceramic ones. If you see this and want it gone, just drive normally and apply the brakes. The brake pads will shave off the surface rust and leave behind shiny new surfaces again.
Rotor rust is normal – not something to worry about if it isn’t excessive and doesn’t compromise the uniformity of the rotor surfaces. Some normal driving and braking is all you need.
With that being said, some drivers complain about having sticky brakes after being stopped, particularly in the rain.
After trying to move, a driver may hear what could be described as a “noticeable bang” This does seem to affect some vehicles while not happening on others. Some drivers have always had this happen without an issue, while others worry about damage being done.
It is possible for pads to become stuck to rotors with a bit of rust after sitting for a while, and this may occasionally be the issue, but brakes are not something to guess with. Repeated damage could lead to compromised rotors and harmful vibrations, depending on what the issue is.
If you have any issues with your brakes, even some slight sticking, bring it up with a trusted mechanic to get an experienced opinion the next time you send your car for some work.
Maybe try using a different brand of brake pads, to see if the specific material is the issue. Take any issues seriously, because rotors aren’t something you want to be compromised.
Excessive Rotor Rust
Again, you probably won’t have any serious issues if your car goes through a couple of rain storms, but if you’re leaving your car out in the elements for a few weeks or months, you will want to keep your rotors in mind when you get back to your car, and check them before you drive.
Minor surface rust may be normal, but anything more than that will be more likely to damage your rotors over time. If this is left unchecked, it can lead to pitting and severely damaged rotor surfaces.
If a car continues to be driven without having compromised rotors serviced, braking will lead to vibrations, and vibrations lead to possible suspension issues. Don’t forget the several hundred dollars needed for a rotor replacement if it can’t be resurfaced.
The Verdict
Overall, wet brakes are rarely, if ever, going to be an issue for the average driver. Rain and puddles (as long as they’re not deep enough to hide something) aren’t likely to destroy anything.
Time and immobility tends to be a larger cause for concern. If you’re going to leave your car immobile for a long period of time, make sure to store it properly, in as a dry an environment as possible.