Question About 1992 Corolla Brakes - Pre-1997 Toyota Corolla and Geo Prizm

How audible should brakes for the front and rear of a 92 Corolla be when they are still in good condition?

Probably a month ago I started to hear a terrible scraping noise from an undiscernable area of my car. In addition, my brakes pulsated as if I could FEEL the scraping through the brake pedal. This prompted me to go to the mechanic where I was then told my front brakes were fine, yet my rear brakes needed to be replaced. This sounded right to me since the person I purchased this car from had the front pads changed around 3 months ago, but had no recored of the rear ones. So, I paid the guys and had them replace my rear pads and turn the rotors with the belief that this was the issue.

I guess this was only a half right assumption though. Less than a week after the repair, I heard and felt the EXACT same scraping noises again. I then took it back to my mechanic and I was told that while it sounded bad, there was no real issue and that if it was metal to metal it would sound much more worse. In addition, I was told that what I'm hearing is normal for cars of this size and type.

I didn't believe it, so I had them replace my front pads regardless. Now, the pulsations are a little less pronounced, but the scraping is still apparent when I brake and it's just driving me nuts trying to wrap my head around the fact I should "normally" hear this from a completely new set of pads. I mean, how is it possible that I would all of a sudden hear and feel this when I never noticed it before??

Could be from a number of things - brakes being the most likely place to start. Need a bit more information.

- How often do you drive the car - is it driven daily or sits for any extended length of time (days)?

- Did they say how thick the front brakes were before they turned them down?

- Did they turn them on the car or off the car (ie. used a portable cutting machine on the car, or pulled the rotor off and tossed it on a brake lathe)?

- Assuming with the brake inspection, they also looked at the suspension and axle, did they note anything unusual (may not apply, some shops won't look at them unless you ask)?

- Scraping noise changes with road speed (ie., faster you are rolling before you hit the brakes, the faster the scraping noise)?

- Anything happened or changed on the car prior to the scraping noise first presenting itself?

- Scraping noise only happens when you brake? Worse when brakes are cold or hot or same? Any conditions that make the noise worse?

- After they performed the brake fix of replacing the rear drums and shoes and turning down the front rotors (should have replaced the pads anyway, unless the pads were that "clean") - did the noise completely stop for a short time or was it still there, just not as noticeable?

- Do you know what brand/type of pad they used to replace the old pads with?

- Scraping noise constant or has periods where it is silent - ie, constant scraping or chirping?

First thoughts - pulsation when stepping on the brake pedal could come from non-use of the brakes, i.e., car sits overnight in the rain or for a couple of days, rotors will quickly form surface corrosion. Will "pulse" the pedal for some time until the pads clean the face of the rotor. Also, after installing new brakes components, there is generally a bedding in phase, where you bring the brakes up to temperature slowly and evenly, then put some more heat into the system to "cook off" any manufacturing byproducts and to ensure that you have a good brake transfer layer on the rotors. If that brake transfer layer is not even, the brakes will "grab" unevenly, causing a pulling / pulsing sensation in the pedal and steering wheel under braking. Could be anything from a shim that is out of place, wire spring that has popped off the brakes, or caliper slides that are not lubricated enough. Could be not even related to the brakes - could be the suspension or wheels making contact with some other component, axle dust shield, etc.

fish basically covered all the possibilities.

There was one issue I had with my front brakes, they kept on going prematurely.

Do you notice any humming or rumbling sound on the highway ??

In my case , the bearings were starting to go and cause micro vibrations during braking and

the rotors would go bad..... tarnish, warp prematurely.

Could be from a number of things - brakes being the most likely place to start. Need a bit more information. - How often do you drive the car - is it driven daily or sits for any extended length of time (days)? - Did they say how thick the front brakes were before they turned them down? - Did they turn them on the car or off the car (ie. used a portable cutting machine on the car, or pulled the rotor off and tossed it on a brake lathe)? - Assuming with the brake inspection, they also looked at the suspension and axle, did they note anything unusual (may not apply, some shops won't look at them unless you ask)? - Scraping noise changes with road speed (ie., faster you are rolling before you hit the brakes, the faster the scraping noise)? - Anything happened or changed on the car prior to the scraping noise first presenting itself? - Scraping noise only happens when you brake? Worse when brakes are cold or hot or same? Any conditions that make the noise worse? - After they performed the brake fix of replacing the rear drums and shoes and turning down the front rotors (should have replaced the pads anyway, unless the pads were that "clean") - did the noise completely stop for a short time or was it still there, just not as noticeable? - Do you know what brand/type of pad they used to replace the old pads with? - Scraping noise constant or has periods where it is silent - ie, constant scraping or chirping? First thoughts - pulsation when stepping on the brake pedal could come from non-use of the brakes, i.e., car sits overnight in the rain or for a couple of days, rotors will quickly form surface corrosion. Will "pulse" the pedal for some time until the pads clean the face of the rotor. Also, after installing new brakes components, there is generally a bedding in phase, where you bring the brakes up to temperature slowly and evenly, then put some more heat into the system to "cook off" any manufacturing byproducts and to ensure that you have a good brake transfer layer on the rotors. If that brake transfer layer is not even, the brakes will "grab" unevenly, causing a pulling / pulsing sensation in the pedal and steering wheel under braking. Could be anything from a shim that is out of place, wire spring that has popped off the brakes, or caliper slides that are not lubricated enough. Could be not even related to the brakes - could be the suspension or wheels making contact with some other component, axle dust shield, etc.

1. I drive the car about 20miles a day

2. I should've asked them that...

3. I think they turned them on the car since I noticed one of the guys grinding the rotors by hand with a

machine.

4. Exactly, the faster I'm rolling before I hit the brakes, the faster and more pronounced the scraping noise

is.

5. Nothing I'm aware of, BUT potholes have been extremely bad in my city lately and I may have forgotten that I hit a particularly bad one.

6. Hmm, lets follow a scale of 0-5 with 5 sounding practically like metal to metal. Before the front pads were replaced, the scraping noise would start out 0 but as I drove more and more, the scraping would escalate to a 4 at it's worst. Then, after the front pads were replaced, the scraping would start out at 0 but escalate to lets say 3 at the worst.

I also notice that the scraping is most noticeable in it's less intense stages when I go downhill. Course, once they get bad enough, I notice the scraping clearly one way or another.

7. The noise is definitely still there. Just a little bit less noticeable.

8. Instinct told me to ask after they were done, but I failed to do it.

9.The noise is constant

fish basically covered all the possibilities. There was one issue I had with my front brakes, they kept on going prematurely. Do you notice any humming or rumbling sound on the highway ?? In my case , the bearings were starting to go and cause micro vibrations during braking and the rotors would go bad..... tarnish, warp prematurely.

Hmm, I'll have to pay closer attention next time I get on the highway. I mostly stick to driving on the city streets.

This is also a dumb question, but is it a bad idea to take this car to a non-import mechanic? The man who originally put the front pads on WAS an advertised import mechanic, but this one wasn't....

Though better to stick with a mechanic that specializes in imports, that is not a prerequisite for good service / proper diagnosing of symptoms. The issue you are seeing, the diagnostic steps needed to be followed, would be the same regardless of what make and model of car it is. Now finding a "competent" mechanic is a whole other ball of wax.

The impact event with the pothole might be significant - as it could have bent a dust shield or forced another component to "touch" some rolling stock. Could be even a rock or other debris jammed in between the dust shields and the rotor/drum. Since the noise decreased slightly after work was done on the front brakes, I would concentrate on that area. Pulsing brake pedal is slightly worrisome, as turning the brake rotor down and replacing the pads should have greatly fixed that.

Since the noise is more or less constant - should be a very short time before you can visually see some damage being done. Look for clean sections of metal, where two parts have ground next to each other. Also, if you can localize the noise, that would greatly help shorten the diagnosing process.

Quick things that can be done - jack up the front of the car, both wheels off the ground, rear wheels blocked and parking brake set to prevent the car from rolling back. Car in neutral, turn the front wheels (car has an open differential, so as you are turning one, the other will be turning the opposite way). Note any grinding/scraping noise - see if you can localize to a side. If you can definitely pinpoint which side it is coming from - remove that wheel (drop the car to prevent the wheel from turning as you try and loosen the lugnuts - unless you have an impact gun) - and carefully inspect the rotating bits as you slowly turn the wheel (can have a helper rotate the other wheel as you listen). Check the inside of the wheels too - see if something is making contact with the inside of the wheel. If there is no noise detected in the front, move to the rear and repeat the above steps.