Brakes Acting Up

[zabcd]

Hi,

My apologies if this has already been addressed. I searched through the forms, and could find nothing which could help.

My brakes on my 2005 Camry LE make horrible metal on metal scraping sound when applying the brakes only under a specific scenario (and that too intermittently): when there is a change in the elevation of the road, for instance going over a bumpy road, or going over a speed bump, or speeding down a steep slope. In every other situation the brakes are absolutely alright, and there is no such sound. I had the car checked by my regular mechanic, who is very good in general, and he couldn't help. He inspected the brakes and told me they are as good as new.

My own research has thrown up a few possible reasons:

1. Bent rotor shield (inspected and ruled out)
2. Worn out brakes pads (can be ruled out based on an inspection by the mechanic)
3. Struts are shot (unlikely as the car has only 30 K on it, and is practically new)

Any advice, or sources for investigation will be appreciated.

Thanks

[JACK_FROST]

have you tried resurfacing the rotors? did you buy cheap pads?

[zabcd]

Originally Posted by JACK_FROST

have you tried resurfacing the rotors? did you buy cheap pads?

Haven't done the former, and I am guessing (hoping?) that with a car at 28 K, that shouldn't be an issue? Re. the brake pads-this was a toyota cpo car and has been driven only 3 K since then, so the brake pads shouldn't be cheap, rather, they should be toyota OEM components.

[gdanaher]

Is it making the sound only when you are applying the brakes over a rough or difficult surface? Does it sound like solid thick metal to metal or thin sheet metal as you mentioned with reference to the shield? There are a couple spring clips in there with the pads. They might be loose or installed incorrectly, or absent. Any pulsation from warped rotors? Are the rotors original or replacements? There was one year (87?) where they changed the rotor and caliper and if you had the wrong combination they would interfere. Perhaps the rotor is the wrong part and it is touching when under certain stress factors. Wheel bearing solid and not much slop? Bearing might be loose and allow the rotor to touch a bit under the right circumstances.

[zabcd]

Originally Posted by gdanaher

Is it making the sound only when you are applying the brakes over a rough or difficult surface? Does it sound like solid thick metal to metal or thin sheet metal as you mentioned with reference to the shield? There are a couple spring clips in there with the pads. They might be loose or installed incorrectly, or absent. Any pulsation from warped rotors? Are the rotors original or replacements? There was one year (87?) where they changed the rotor and caliper and if you had the wrong combination they would interfere. Perhaps the rotor is the wrong part and it is touching when under certain stress factors. Wheel bearing solid and not much slop? Bearing might be loose and allow the rotor to touch a bit under the right circumstances.

Indeed, it's the case only when going over rough and difficult surfaces, otherwise the brake performance is completely fine. It sounds like a solid thick metal to mteal. If my mechanic had not told me the brake pads are okay, I'd have said the brake pads needed to be replaced. There is no pulsation whatsoever, and the rotors should be original.

The other ideas are interesting-thanks for those, I will need to check on those.

[gdanaher]

One additional thought. It might not be the brakes as such. Jack the car and pull the tire. Place a second jack under the steering knuckle and force the strut upwards about to the point where it is supporting the full weight but not quite. Make sure the car is on a jack stand. At that point, see if it is fully clear of the spring and everything else.

[somick]

Ask your mechanic to retorque the axle nut.

Just a thought though...

Sam

[gdanaher]

Do you get this sound only when touching the brakes, or do you get the sound without braking?

[jayrguidaben]

it might be a dirty caliper.
i had the same problem when i install a new oem brake pads after 80k and forgot to put brake caliper grease.
when i apply brakes hard i had the grinding noise. what i did clean all bolts, bushings, holes, pins, insert and anchors. lubricate all parts with a light coat of grease including bolts which mount caliper to vehicle.
after that its all gone.
just my o2.

[zabcd]

Originally Posted by gdanaher

Do you get this sound only when touching the brakes, or do you get the sound without braking?

Hi, Only when touching the brakes, and not otherwise.

[zabcd]

Originally Posted by jayrguidaben

it might be a dirty caliper.
i had the same problem when i install a new oem brake pads after 80k and forgot to put brake caliper grease.
when i apply brakes hard i had the grinding noise. what i did clean all bolts, bushings, holes, pins, insert and anchors. lubricate all parts with a light coat of grease including bolts which mount caliper to vehicle.
after that its all gone.
just my o2.

This is quite possibly what is happening here as well. Most likely the bozos who prepped the car as CPO just forgot to apply the grease. I am wondering though, if this were in deed the case, then why would the sound come up only intermittently and over rough roads/ slopes

[jayrguidaben]

it might be when your applying brakes hard on down slopes and rough roads causing to grind. i noticed mine when going to a stop sign and brake hard. just do that first (grease the caliper parts). or clean the brakes pads it self with sand paper.

[sniper34]

Did your mech pull ALL four wheels? Sounds to me that you have a pad hitting somewhere.

[gdanaher]

Find someone with gray hair to drive your car a little and give an opinion.

[dorman68]

My car did the same thing. I had cheap ass brake pads on the car, I replaced them with thermo quiet pads and problem solved.