recurring brake problem

[matta46]

I replaced my front brakes and rotors about 1.5 years ago, and after several months, I got vibration when I applied the brakes. After living with it for a while, it progressively got worse, so this past September I replaced the front rotors, and that corrected the problem until about December. Now the vibration is back as bad as it was before the 2nd replacement. I used Napa premium ceramic pads and first I used Napa Premium Rotors. But after thinking the rotors were the problem, the 2nd time I used AC Delco rotors. This was also my first attempt at doing a brake job myself. I did make sure to clean the surface of the hub thoroughly before putting the rotor on, and bedded in the rotors by doing a series of 30mph-0 stops. Could it be bad pads causing deposits on the rotors? Some underlying cause like a worn out hub or steering component? Something else? Car is a 2003 SE with 200,000 miles.

[maxi426]

I know you said that you cleaned the hubs, but still thinking that. Be sure that you've cleaned the entire surface down to bare metal. Some get pretty crusty, and the rotors wont run true.

[crash93ssei]

I don't think 30 - 0 stops is helping. Typically I find a back road and do two or three hard slow downs from 70 - 10 then a couple more easy normal slow downs from 70 - 10 then I drive around for a while letting the brakes cool down good, I have never had an issue doing it that way. Of course 60 MPH will work too, I just do 70 as its pretty open around here.

[MKMike]

You've mentioned a number things--all of which are possibilities.

Vibration when applying the brakes can have causes other than the brakes themselves.
If there is a worn steering component, you can get a vibration when the brakes are applied.

Heat is an enemy of good braking.
Heat builds up due to repeated application of the brakes with little/no cool off in between.
Sudden, hard stops. (Better to get a pedal pulsation than a wrecked car,though.)
Riding the brake. Some people have a habit of driving with one foot lightly applying the brakes.
Other people brake much more often than average (tailgaters and very anxious drivers).

Sticking brakes due to caliper pins sticking, parking brake not fully releasing, faulty brake hose not allowing fluid to leave the caliper, even grooved mounting hardware that fails to allow the pads to go back when the brakes are released can cause heat buildup and other issues.

In addition to using quality rotors, quality pads are essential.
Ceramic pads are harder and can be more prone to pedal pulsation issues.

Since this was your first brake job, I'll outline where things commonly go wrong during the job.
Failure to do things this way often leads to problems:
1) Clean and lubricate the caliper slide pins with a caliper slide pin lubricant (such as Sil-Glyde)--not just grease.
Grease will not suffice, since it swells seals and can't withstand the high heat of brakes.
2) Replace any pin that is pitted or grooved
3) Replace any torn slide pin dust boots
4) Clean or replace the brake pad mounting hardware. (Discard if any grooves are worn in.)
5) Clean the hub surface of rust (Also clean the rotor's hub of rust if reusing rotor.)
6) Replace any shims on the backing plate and use an anti-squeal compound
7) Properly torque the lug nuts



If you feel a brake pedal pulsation when the brakes are applied, that would usually narrow it down to the brakes themselves.
AC Delco rotors come in different qualities. The best is OE, the second best is Professional and their bottom of the line is Advantage (no better than any other Chinese made parts).
A sudden hard stop when the brakes are already hot, can cause a pedal pulsation because a large amount of friction material gets deposited onto the rotors.

More info on that here http://www.powerstop.com/what-causes-brake-pulsation/
http://www.brakeandfrontend.com/10-of-y ... questions/
http://www.hendonpub.com/resources/arti ... ls?id=1787

[96 SSEi]

if your brake vibration is only when you apply brakes, I would assume warped rottor - be sure to torque all lug nuts to 100 foot/lbs and you wont have a problem with rotors again

[jradke61]

Never been a fan of ceramic pads. I'll replace pads more often rather than deal with warped rotors from excess heat.
Not saying this is your problem.

[bobc997615]

I'll agree with "sticking" caliper pins. It causes the caliper/pad assembly not to "center" on the rotor, thus causing hot spots that warp the rotor.