2000 Alero - Humming Noise, Brake Problem?

[silverhulk]

Initially, the problem I had was a rubbing noise coming from the front wheels I could only hear at low speeds, 10-15 mph. Also, when I would depress the brake pedal I would hear a squeaking noise, even in a stopped position. I took it to a mechanic and he said it was the front rotors and pads. I had them replaced and the rubbing noise remained but the squeak went away. When I got the car up to 60 mph after the work was done I got a humming noise when I depressed the brakes and it remains even after I stop braking. I have to stop the car completely and it goes away after that. It only onsets when braking at high speeds, 50-70mph, not at low speeds. Also after the first time that happened the squeak came back. Could it be related to the rubbing noise? If not, what could it be?

[ctesla]

hey Jason,
welcome to AF.
how many miles on your Alero?

but would you say it is a rubbing hum, or a low rumble, and is it only once at the high speeds, or steering at the higher speeds?

might be your hub bearing going bad?
you could put it up on jack stands, have someone inside put it in drive, and be out by the wheels and listen while other person applies brakes, revs a little, brakes and steers, etc.
if the squeek has come back, might be the dust plate got bent a little when the mechanic was in there, and is rubbing the rotor, or it might be the mechanic used inferior pads and/or did not apply any anti-squeel or caliper lube...
post back if you isolate that noise,
chris
nrt racing

[silverhulk]

Thanks for the reply.

It has 55,000 miles on it.

After driving a little more with the problem it starts as a hum but when I slow to stop it starts to sound like a low rumble, as if something is shaking around. When I hit the brake pedal, the pedal vibrates and the noise becomes more prominent.

Turning the steering wheel doesn't affect it in any way. I can drive at high speed no problem then once I hit the brake the noise starts. Also the noise remains even when I come off the brakes. It fades in and out then comes back completely when I hit the brakes to stop.

I was thinking the caliper might be sticking, but then why would it be only at higher speeds and why would the noise intensify when I fully apply the brakes?

Any other ideas as to what it might be will be helpful. I'm going to get it to a mechanic sometime this week. I'll be sure to update if I find out what it is.

Thanks.

[kymagred]

I replaced the front pads on my Daughters 2003 about 3 months ago. (her car has drums on the back) Now I hear the low hum also. Could not hear it when I first started my trip today but after 30 miles its easyto hear. Sounds to me its from the right side of the car. After stoping I can let off the brake and let it coast and can still hear it hum. The right wheel does ot feel any hotter than the left. What do you guys think?? Thanks T

[vamc]

The humming is when when the brakes and roter heat up. remember, the roter can reach a temp of 1500-2000 digrees. i think its the roter(s) and brakes together. i beleve the sloted roters will not do this because it will disapate the heat, which will cause less heat and better breaking. now i m not saying this wil end the problem, but something to look and think about. My 2 cents.

[Chevy454man]

this humm noise is common on these vehicles when the rotors are resurfaced-it creates a harmonic vibration from the circular cutting of the rotor-only solution is new rotors and good pads-the squeak is the seal on the piston in the calipers-new caliper time!

[kymagred]

Originally Posted by Chevy454man

this humm noise is common on these vehicles when the rotors are resurfaced-it creates a harmonic vibration from the circular cutting of the rotor-only solution is new rotors and good pads-the squeak is the seal on the piston in the calipers-new caliper time!

Thanks for the reply. I didnt resurface the rotors I just replaced the pads. But I may replace the rotors. Do they make drilled/ sloted rotors for these cars? T

[silverhulk]

Originally Posted by kymagred

Thanks for the reply. I didnt resurface the rotors I just replaced the pads. But I may replace the rotors. Do they make drilled/ sloted rotors for these cars? T

I actually fixed my problem, just didn't get around to replying. I pulled off my front brakes and saw there was uneven wear on the front left side. I didn't want to fuss around replacing part by part so I bought OEM calipers, rotors, and pads.

The one thing I noticed was that the OEM rotors were much thinner than the after market ones I had originally purchased. Also the OEM pads were semi metallic, I had replaced them prior with low grade ceramic, not the good ceramic pads.

Anyhow the calipers were obviously the issue due to the uneven pad wear. After replacing everything, it works great, no more problems. After bringing it to 3 different mechanics, even the dealership, I took care of it myself. I actually got the OEM parts off ebay for less than $100, from a car that was totalled at 25 miles.

Though the calipers were the main issue, the fact the OEM rotors were almost half the thickness of the aftermarket ones may have had something to do with the pads coming into contact with the rotors more easily when not braking.

Hope this helps. Good Luck. Any questions just reply.