Vibrations while braking. can't seem to get rid of it!!

[ashwinhj]

Hi,
I have a 1999 Camry 4 cylinder w/ 142,000 miles. Since last year I noticed a grinding sound while braking at high speeds but there were no vibrations. over the period of next 2 months, I felt vibrations in the steering wheel and brake pedal along with the noise. My local mechanic recommended replacing the front rotors as he noticed them to be uneven. That did not solve the problem completely so he again took a look and this time replaced the left rear rotor.

There is less vibration but it is significant enough that even my wife mentioned it while riding in the passenger seat. The local toyota dealer suggested replacing front rotors as well as front pads even though the front pads measured at 9/32. Any suggestions on what could be causing the vibrations and noise?
Thanks.

[mail2_jb]

I had horrible vibration after maineke did a brake job with rotor machining. Turned out, the sob mechanic took too much of the rotor or unevenly machined it. Anyhow, it got to a point that I couldn't take it any more. Took it to another mechanic, he replaced both rotors (kept the pad as is, because it was almost new) and the problem went away. No vib even after 4 years on the same economy rotor (don't know which brand he put, but he charged $200 that time for parts and labor. I bet he put some generic from azone, advanced or oriely). If you are DIY-er, you can get rotors from advanced for $20 (use P20, Visa etc coupon codes to see the price), don't know the quality of the rotors, other can give a better answer on them and change it yourself. I just replaced two with these cheapos and hopefully it will hold up.

[JohnGD]

Poor workmanship gives the whole trade a bad rap.

But yeah there are plenty of ~$20 rotors (Centric, Raybestos, Wagner etc) that are double-disc ground with non-directional finish that work very well, so go with these and not the headaches.

(For these cars IMO Akebono ProAct and Centric C-Tek is a good value combo.)

[ashwinhj]

Since the vibrations didn't go away, my mechanic ( which is a NAPA repair shop) replaced the newly installed front rotors with new one's since he thought the 1st one's were defective. with the new one's it still drives the same so he suggested it was not the front rotors.
I am thinking of replacing the front pads based on the dealers recommendations but don't want to spend anymore money if that is the the root cause. do you guys have any other suggestions on what else could I ask my local mechanic to check?

[BMR]

Just a couple of thoughts:

Check the calipers to make sure they're floating properly. If they're jammed up, even the slightest rotor runout can cause pulsing.

Have them look closely at the wheel bearings. You mentioned a "grinding sound while braking at high speeds"; that could be bearings.

[fenixus]

I would sand the pads down a bit to remove old glaze and possible grooves from old rotors and such.

as above, make sure your calipers piston and slide pins are moving freely and not pressing the pads at an angle or unevenly?

flush or at least bleed the brake fluid too while at it.

[Mister_Perkins]

i would say it sounds like you might have a problem with your caliper(s).

I recently changed the passenger caliper on my 95 Camry because it was sticking pretty bad. Caused extreme vibration when braking

[Nark]

Same as above. One thing I've learned after I got screwed by the dealer. Properly working caliper or wheel cylinder will compensate for the disk or drum unevenness. That's a $540 learning curve for me. Another thing is, if one caliper defective, all others will soon follow and the entire system need to be flush. Dealer did my rear brake and I did the front. Both front brake are dragging the wheel and slow the car down a bit.

[julyaric720]

Poor workmanship gives the whole trade a bad rap.

[JohnGD]

Yeah if the rotors aren't the problem then check the anchor pins and the caliper pistons. If there aren't rust problems I'd just rebuild them.

The rebuilt calipers these days no longer come with anti rust coatings.