Water sound in front when braking in slow traffic

Never ever heard this before so I gotta ask for some help. Had new front brake pads and rotors put in about a month ago. Just the other day while in slow traffic, creeping up a bit here and there, I began noticing what I can only describe as a watery/sloshing sound when braking. It takes hitting the brakes a little harder to do but it’s there and it’s one of the most bizarre noises I’ve ever heard from a car. I can say it is very possible its not fluid of some sort but instead is something wrong with the actual brakes going against the rotors, but I must say it definitely at least SOUNDS like water.

One key note: The noise does NOT happen right after starting the car up. It takes a good 20-30 minutes I’ve realized, to begin. I also have a feeling it may have something to do with the heat being on in the car as it’s only been very recent where I turned that on in my car. Cold weather really just started to kick in here in NY.

Any thoughts??

just to rule it out . shake the car doors by open and closing part of the way quickly when your parked. sometimes the vent holes in the bottom of the door can get clogged. when it rains the water has nowhere to go but stay at the bottom of your door. and you will get that sloshing sound.


If there were water in the doors I would hear the water rushing back when I started accelerating which I don’t. Also it takes a good 20 mins for the sound to start anyway.

It might take that long for the water to thaw. Could also be a blocked HVAC drain, again possible the water freezes and you don’t hear it until it thaws.

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True, but this noise definitely seems to be coming from under the dash area and not to the side of me in the door. I can also hear some friction when braking. The pad against the rotor I’d say. Again I don’t know if its actual water for certain, but instead could just be something mimicking that type of sound. Really it could just be a very strange squealing noise while braking, but then again if it were the brakes themselves wouldn’t that sound start happening when braking right away as opposed to after a half an hour of driving?

The cooling system is low on coolant.

And what you’re hearing is the coolant running through the heater core when the water pump slows down.



Thank you. I will check the coolant tomorrow.

Coolant looks a bit low from what I can see. But wouldn’t a dash light warning come on if it were too low??

By the time a temperature light comes on, it might be to late.


Just something I left out though I didn’t think it could have anything to do with this…

Just two weeks ago this car was in a body shop having a new front bumper put on. I’m assuming most of the front end was taken apart. I wonder if some sort of drain wasn’t properly put back in its right place maybe…

In most cars, no. Your owners manual will describe this feature, if your car has it. Also how check coolant level.

On my 1999 Honda, with engine cold, open the radiator. Coolant should be right up to the cap. Close radiator and look at the overflow tank. Level should be between the Cold and Hot line.

I have yet to see a car with a coolant level light. I suppose it is possible, but the coolant level in the reservoir is easily visible when you do your weekly oil level check.

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My guess is you’re hearing the engine coolant sloshing around in the dash, like Tester says. Has nothing to do with your brakes.

Check the coolant level and top it off as needed. If the coolant gets low again, you’ve got a leak somewhere.

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why was the front bumper replaced? Accident? if so, how severe?
did the front bumper replacement have anything to do with the brakes needing replaced?

probably non-related (as this sounds like a low coolant situation or clogged HVAC drain to me,) but it is possible something else is going on if this vehicle was recently in a wreck.

No accident at all actually. Just wanted to replace a scuffed up / scratched bumper

So upon closer inspection the coolant level was right around the minimum mark. I topped it off with some coolant and that’s all I can do right now. Will have to wait and see if this was a fix. I still find it very strange how I’ve been driving for over 20 years now and never once had this problem/sound before.

In some cars, you need to have the heater set on Hot to get the heater core fully open to the rest of the cooling system. That can make a diff when you are draining, or topping up or refilling

the system might need to be bled to get the air out. like Tester said it might be air in the heater core.

Make sure the coolant level ok, but also that the coolant has enough freeze protection for your area. Sometimes a cooling system problem during the summer will be corrected by simply adding water, which will raise the freezing point. If the coolant’s freeze protection isn’t down to the freezing point required, there may be slush forming in the coolant, which could cause this sort of symptom.

However, my first guess is the AC system’s drain is blocked. You might wonder why the AC would be on in the winter, but whenever you turn on the windshield defroster the AC turns on. It helps remove moisture from the passenger compartment. Perhaps you’ve discovered where that moisture is going. Unblocking that drain is usually pretty easy using compressed air, done from the under-side of the vehicle.

If the AC drain was clogged up with water, it would be heard during every single brake back and forth swishing. This sound of water I am hearing does not appear until a good while after driving.