Creaking Sound from Front of Prius While Braking

I am trying to troubleshoot a sound that I've begun to notice coming from the front of my '08 Prius. I've had this car since new, and it now has a little over 40,000 miles on it. (Please note the sound I'm referring to is not the brake pump electric "whirring" noise that happens evey so often, it's definitely something new/different.) I first noticed it maybe a year ago, but it seems to be happening progressively more often.

It's best described as a "creaking" sound, which is to say it sounds a lot like the noise that an old creaky staircase makes. The sound appears to be linked to when I am applying the brakes and the car is coming to a stop (perhaps from 15MPH down to 0). If while I am hearing it, I lift my foot off the brake pedal, the sound goes away. It seems to also go away if I press down harder on the brake pedal.

Also, after driving for a little while, the sound sometimes will go away, and I might not hear it again until the next time I take the car out, although sometimes it does come back a little later in the same drive, again always while slowing to a stop.

It almost sounds like it could be creaky suspension, but since it seems tied to the use of the brakes, I'm wondering if perhaps it could be the brake pads? I have yet to replace the pads on the car, but at my last inspection at the dealer a few thousand miles ago, they reported the pads were still good.

So...with that, does anyone have any ideas what this sound could be? If not the brake pads, perhaps there is a part of the brake assembly that needs adjusting and/or lubricating?

Hoping that a Prius guru can help point me in the right direction!

Thanks in advance for your sage advice.

 

Thanks everyone for the replies. I think we're on the right track here. I am going to take the car in to my local mechanic tomorrow for a front suspension and brake inspection. I'll have him look for a worn suspension component (such as a rubber bushing), or perhaps a worn brake rotor. I peered through the wheel covers to look at the rotors and I did not see rust. There are radial lines visible, like those of a vinyl record, but even so, the metal is clean and smooth to the touch.

It's true I don't drive much, averaging only about 5K per year, but the car never sits for long periods without being driven. The low mileage is mostly due to the fact that I work from home and do only local driving. The car is garaged. I have tried the brake cleaning method that EdTheFox suggested a few times in the past, but it did not fix the problem.

The idea that it could be the suspension making noise as the momentum (and weight) of the car shifts forward while braking makes a lot of sense to me. Especially since I often hear the noise while braking on a downhill (as we live at the top of a hill). It certainly sounds like a creaking suspension, but as mentioned since it appears tied to the brakes that was my first thought. Other than a rubber bushing, are there other specific suspension parts I should have them look at?

By the way, I found this video on YouTube of a Prius with creaking struts. This sound is fairly similar to what I'm hearing (though the cause may be different). However, I don't hear the creaking when going over speed bumps, or turning the steering wheel while the car is stationary...only when coming to a stop.

-Kizzy

 

I appreciate the good info. Will report back here tomorrow after the inspection. Keeping my fingers crossed it's something simple...and inexpensive.

No plans to sell the car, as she's been super reliable (thus far), and this has been the first issue I've had to deal with in 8 years....but thank you!

-Kizzy

 

I only posted that video link as an example of the sound I'm hearing....that's not actually my car.

 

Just a quick update. I went to my mechanic this morning for an inspection of the front suspension and brakes to see if we could determine the source of the intermittent creaking noise. When I first arrived we took the car for a road test, and of couse (Murphy's Law) I couldn't reproduce it. So I did my best to describe the sound, and where it was coming from, and also gave them the information I was provided here on PriusChat (i.e. told them to look for worn bushings or other rubber components, perhaps a worn or cracked rotor, etc.). They put the car up on the lift and looked at he complete brake and suspension systems....and couldn't find a thing wrong with either. Everything looked in fine shape as far as they were concerned, the car is tip top. And this is a very reputable mechanic who has been in our community for 40+ years.

And of course the whole way home I didn't hear it at all either...I only heard it just as I was leaving the house to drive there. They said that if it gets to the point where it's doing more often and is easily repeatable, so they can actually hear it, to bring it back, but otherwise not to worry about it for now. So...I'm just going to happily take their advice and move on.

-Kizzy

 

In my case, the creaking only usually occurs if the car hasn't been driven for several hours. Then I will hear the creaking noise as I am coming to the first few stops. After that, it goes away. Sometimes it will come back a few miles down the road, until disappearing for good -- that is, until the next time the car sits for a few hours. Then, repeat.

I live at the top of the hill, so when the car is parked at my house and sitting for a while, those first few stops are on the way down the hill. As exstudent suggested above, perhaps this is an additional factor in the momentum of the car shifting to the front while braking, causing the front suspension to depress a little bit, producing the creaking sound.

I am beginning to think the problem could be a strut that is beginning to be faulty. It does appear that the drivers' side strut (which is the side the creaking seems to be coming from) has experienced some very mild seepage, so that could be an indication.

Another possibility from what I've read is that creaking sounds can also be caused by a caliper sliding pin that needs lubrication. Maybe what is happening, is that after the first few creaks, the part in question is becoming sufficiently lubricated (with whatever lube remains) to not make the creaking noise any more.

The mystery continues.

 

A few months have passed and the creaking sound while braking persists. Now that I've had more time to observe it, I've realized that the creaking noise only actually happens when I am am braking to a stop AND turning the steering wheel to the right, like when I'm slowing down to make a right turn around a corner, or braking down a hill that is veering to the right. I do not hear the creaking sound while going over speed bumps (braking or not), nor do I hear it if I'm slowing down with the steering wheel pointed straight ahead or to the left.

I've also been able to determine that the sound is coming specifically from the front left side of the car (i.e. the driver's side).

Even though my mechanic did a visual inspection of the suspension and brakes and didn't find anything wrong, I am still wondering if the problem could be that a suspension bushing, and/or the front-left brake caliper slide pin needs lubrication. (My mechanic did not lubricate anything last time, only did a visual inspection). I'm also wondering if perhaps the problem could be the front-left strut or strut mount.

Now that I know how to reproduce the noise, I am going to go back to my mechanic again and see if we can pinpoint the problem this time. Will report back after I do. In the meantime, if anyone has any other suggestions of what I should have them look for, please let me know.

Thanks,
Kizzy

 

Will do. That's interesting that your '08 makes the same noise.

 

Just a quick update to this thread. While waiting for the chance to take my car back to the mechanic, the mystery creaking noise has disappeared! It has been about 3 weeks now since I last heard it. Not sure what changed, or what could have fixed it, but I'm happy it's gone. We did have some unusually hot weather here in Los Angeles the second half of June (around the time I first noticed that it went away), not sure if that had anything to do with it or not. Perhaps the heat (one day was over 110 degrees), could have re-activated some dried-up lube on a bushing somewhere? Seems doubtful, but who knows. Anyway, I'll will report back here if the noise returns. Thanks to all who have followed and chimed in with advice.