ajg617

Just reading StopTech's article on the Hawk Blue pads and uneven brake pad deposit. My brakes developed a vibration (Audi rotors and pads) under moderate and heavy braking, particularly at high speeds. I know I'm hard on brakes, the continuous high speed stops (65 to 0 repeatedly each day) has taken a toll on any of the front brakes I've installed. But I was surprised that the Audi parts started shaking after only about 20K miles. They now vibrate on braking even when cold.

So, can you visually see if you have additional deposits on the rotor? I can't see any markings on the rotors as they appear uniformly shiny and no sings of brake pad outlines (though I did see that on the prior non-Audi rotors).

jcman

Yep been there done that with ATE rotors before, I've found out that the best rotor for everyday driving is the Zimmerman Z coated ones and they don't rust on the non contact areas after 36k miles.

Sounds like your rotors are warped.

rallymarty

Just playing devil's advocate here, but I seriously doubt actual warping of the rotor. It's cast iron, it melts at 2100*F. You can pick up a cheap dial indicator and magnetic base from Hazard Fraught Tools and get an idea of how bad it is. Might be able to see some deposits in the form of a pad outline. Saw pad outlines with the rear rotors on my WRX.

You stated hard stops from 65 to 0. I think that is the cause for the high probability of pad deposits being the problem. Perform high speed (70 mph) hard stops, but DO NOT come to a complete stop. Release the pedal around 10-20 mph and repeat a few times. Probably best to do this on a desolate road or large parking lot. Give the rotor and pads a rest for a minute while driving, as this will aid rotor cooling. Repeat 5-10 times. Be careful of fade, don't endanger yourself or others. If the pedal gets soft, give it 5-10 minutes of drive time to cool down. Scared myself ****less one time by brake fade in my Corrado having fun on my parent's rural road when I was a young buck.

Just my .02. Good luck.

SloopJohnB@mac.com

That's called bedding the pads/rotors…the stoptech article on the blue pads refers to using the highly abrasive pads to remove uneven pad deposits. Use the blue pads to remove the deposits and then switch back to street pads and rebed the street pads onto the now clean rotors.

SloopJohnB@mac.com

No..you won't generally see the uneven pad deposits…the stoptech article on the blue pads refers to using the highly abrasive pads to remove uneven pad deposits. Use the blue pads to remove the deposits and then switch back to street pads and rebed the street pads onto the now clean rotors.

However, as RallyMarty says, you may be able to clean up the vibration by attempting to rebed the pads…the key is not to stop the car while the rotors are really hot which can cause uneven pad transfer. Driving on the street such that you have to go 65-0 frequently seems a little outré. If that's the case you should probably upgrade to a better/more aggressive pad such as Hawk HP+ and live with the dust. Or find a less taxing commute.

ajg617

Maybe when I retire, I'll be able to find a less taxing commute. Those who drive around Boston probably know the highway I'm referring to (but you can pick any one as they are all the same). There's a stretch of about 10 miles where you turn directly into the sun on at least three occasions, on the way to and from work and combined with all the merges, you can be cruising at 70 plus, come up to a curve or hill and see traffic at a dead stop in front. Because of the hills and curves, you can't see far enough ahead to begin to slow down before you are on the brakes hard. Between merges all lanes are up to 70 only to dead stop at the next merge a couple of miles down the highway. Average number of high speed dead stops is 5 depending upon sun and time of day. Unfortunately, there is no less taxing route without adding an hour to drive time. In other words, you can't get there from here