Saturn Sky Forum banner

Odd sound after brake install

371 Views 13 Replies 6 Participants Last post by  LAC Sky
I recently replaced both pads(semi-metallic) and rotors on all 4 corners with some drilled and slotted ones I bought from brakeperformance. I've noticed the brakes make a weird noise, they make a sort of zeeeeeeee noise when driving. Constantly, at anything over 20mph and it gets more pronounced the faster I go. If I have just started driving(cold rotors) when I barely give brake pressure the noise goes away. However after about 5 minutes of driving pressing the brakes makes the sound louder.(If the radio was on at regular volume the sound is unhearable, but with no radio and after you hear it once its very easy to catch even to passengers) The install was done by a family friend who is an ex GM master tech and now teaches automotive at a local college. And he did the setting procedure so I don't have any thoughts that installation error could play a role here. It might be nothing or even wind noises as it goes in and out of the slots/holes but I wanted to know if anyone else has ever done slotted and drilled rotors and has come across anything like this?
1 - 14 of 14 Posts
Define the odd sound you are hearing? Zeeee noise is puzzling.
Maybe a audio recording from your phone might
help our owners with their suggestions about this issue?

Since the install was done by a former GM master tech- I doubt there was an install issue.
It might be a parts defect- but the GM guy would have noticed it.
New brakes & pads need a bedding in process. It might go away- then again maybe not.
Imo- you can never go wrong with new stopping power for your ride.
I was never a fan of crossed drilled rotors- but that's just me.

One of our owners will chime in with some clues to help you out.
I would ask the GM guy who installed them- what he thinks this sound is.

Luck with it.

See less See more
I have not heard of that being anything normally associated with slotted or drilled rotors, and am not a fan of them so I have no personal experience, but it does not seem normal.

A call to the seller may be helpful as they can certainly tell you if it is normal. What does your friend think? He would be the first one I would ask, since he can presumably listen to it in person.
  • Like
Reactions: 2
Slotted rotors are mostly bling today and drilled can be a negative, but people still do it mostly for looks while pretending they are doing it for performance. You can actually get cracking starting at the drilled holes, so I tend to avoid them unless they are OEM as they are on one of my cars.

Having said all that, I don't recall the drillings causing any particular noise and have a hard time figuring out how that could happen unless there is something touching something else that it shouldn't, all things being normal. I'd be tempted to take it either to the guy that did it or to someone else and ask them to diagnose the noise (they can do things like apply an on car wheel balancer that spins a wheel up, and then watch/listen as the brake is lightly applied.

Frankly, I think you are right to be bugged by this - bits making sound is often caused by bits not supposed to be in contact which on a braking system can be bad news.

BTW, I have zero noise associated with the car that has drilled discs nor with another one that has slotted rotors.
See less See more
  • Like
Reactions: 1
Difference in sound while braking could just be the sound of the new and different pads rubbing against the new and different rotors - nothing wrong, just different and not familiar. As for noise while NOT braking...did the tech change the caliper hardware? Lubricate properly? If the calipers aren't sliding smoothly, one pad may be making light contact with the rotor at all times. The noise might diminish in time, but you may never have optimal braking.
I would follow up with the installer but it could be a dust shield rubbing on a rotor. Very easy to bend these slightly and cause odd noises like you mention. Happens to the best of us.
  • Like
Reactions: 1
I'm going to have him diagnoise it for me. I went with them for the astectic but I was unsure whether they were supposed to make noise. I'm working on getting an audio clip, since it won't let me attach just an audio file here
I'm going to have him diagnoise it for me. I went with them for the astectic but I was unsure whether they were supposed to make noise. I'm working on getting an audio clip, since it won't let me attach just an audio file here
They should not make noise.

Audio files are not attachable, so most people post them to YouTube (or something) and attach a link.
I had a loose brake shield on my front driver side rotor that made an odd noise once.
This sound was not constant however, only while turning to the right.
Dealer, tighten all screws to both shields, and I have never heard the sound again.
My brakes are due for an over haul soon, but you shouldn't be getting a constant sound
from them during operation.

Let us know what the GM guy says it might be- just so our community can take note of it.
New brakes cost money, they can save your life, you get what you pay for- but you shouldn't
have any noise coming from them at any time. If it was an install error, it should be fixed at no charge.
If on the other hand- there is a problem with a new part- that should be replaced the mfg.

A little bit of an update. I haven't driven the car in a few days since I'm off work. But I will have a video on Monday that will have the sound. He took it on an extensive test drive on the highway and city streets. He noted that he does hear the sound, but sometimes it sounds almost off-beat. When i hear it, it was a constant zeeeeee noise. However he noted a pulsing sound. The sound comes in, dies off and comes back. But happening about 5 times a second, zee.... zeee... zee... etc he said that he noticed it on the orignal install and it didn't seem to be something to be concerned of but did say hat he had seen slotted rotors make a hiss sound during rotation in the past. So this was a possibility. I will note that i had the rear diff fluid done by the same guy. He took it on a test drive after that and noted that there we're no odd noises coming from the rear diff, specifically noting nothing during slow tight turns. This was echoed after the most recent test drive stating that he doesn't believe it's anything diff related. I just worry about it since I've heard many people here with rear diff issues. Dad who also works along side this tech suspects it could be something drivetrain related but is unsure otherwise and doesn't think it has anything to do with the brakes. Tech said if it got worse we would happily dig deeper but that it doesn't appear to be anything to be concerned off since it's very unnoticeable. But I will upload a video Monday and hopefully I can get to the bottom of this
See less See more
Well it is good that you had the installer look it over- take it for a test drive for his evaluation in different scenarios to ascertain what it might be- to this noise.
Off beat... he noted a "pulsing" noise.
He noticed it before- but was not concerned about it. Slotted rotors making a "hissing" noise.

It is not drivetrain related. That's a good thing. Not the brakes. It is very unnoticeable to him but not to you, cause you hear it all the time if I interrupt this description correctly?
It the noise- hisses and pulses.
If it gets worse- a deeper dive into the world of hissing & pulsing.
Sounds like something from Hollywood if ask me.

I've been known to make hissing and pulsing noises during the love making process but.. that is another story.

Brake booster? Proportioning valve?
We've all heard a power steering pump whine when low on fluid.
There is no vibration from the new rotors. There is no brake fade.
Is it enough time- for the new pads to be bedding in to the new rotors?

Maybe the video on Monday will tell us more about this problem.

See less See more
It is noticeable to me, and to him. But you have to listen for it. Radio at normal volume and you can't hear it. The sound is noticeable at all speeds above 20mph, when off the brakes. He believes it could be drivetrain related, but is confident it's not the rear diff. Possibly a brake hub rubing? They both believe its nothing to be concerned about, i would just hate for it to be an actual problem down the line. It's present in the rear of the car only and on both sides. I also noticed this substance. The picture makes it look blue but it's actually white. Not sure that that coul be or if its related.

See less See more
Here is the video. The sound is somewhat noticeable at points and other times it's hard to hear so I recommend full volume. In the video sometimes I am on the brakes other times I am not. It appears that being on the brakes only amplifies the sound. I put the car on jack stands and ran it to about 40 just to have someone else hear it and they determined it was most likely just air going through the spaces in the rotors.
I do hear the humming sound- very slight but noticeable.
What it is- I'm not sure, so the GM guy might just be right
in his opinion that it is air flowing-through the drilled holes in the rotors.

Since there is no other odd sounds related to this new brake set up,
grinding or rubbing noises, no fade to the pedal, no pulsing of fluid,
no warning lights flashing in the DIC- I think you might be ok here.

IF it were something else besides the new brakes- you would know it.
The hub bolts should be checked- for torque specs on occasion.
Brake shield backing plates attachments points should be tightened.

Look for signs of any new wear, or shinning metal rubbing the new parts.
Brake fluid level checked often, hoses/fitments, caliper squeal, any pulling
to one side or the other, when applying the brakes.

After they have been bedding in some maybe a good old fashion panic stop-
just to see how they do stop the car under different conditions.
If you don't run into any new issues- you should be ok I think.
Then again- if do you notice something abnormal in the future
with their performance level or lack thereof- have the GM guy look them over again.

If your brakes don't stop you- while you're out & about something else will.
The neighbor's car, his trash bins, his wife's new flower garden, the odd
tree, concrete barrier, cement truck- you know normal obstacles.


* Not really an edit on my part- just an additional thought of mine.
The only time I've heard this humming type noise or read about it here on
the forum was that for some of our owners- is from the rubber seal, above
the plastic cowl to our windshield. If yours has a gap between the glass or
the cowl itself- this could be a source for this humming sound- maybe.
Just my 2 cents worth.
See less See more
1 - 14 of 14 Posts