Front Brake Vibration
09-06-07, 08:32 AM
#1
Pole Position
Thread Starter
Front Brake Vibration
I mentioned to my service advisor about Front Brake Vibration as my RX brake pedal would shudder during stop and go driving, mostly on streets with stop signs. I also mentioned to him about TSIB BR004-04 (which falls in-between my VIN #), but yesterday he called me back and said "Brakes are healthy, rotors are warped - some noise are normal". But Lexus did the following: "Performed rolling deglaze to help with short trip brake squeal".
Lexus did not perform the above TSIB. Last year, I had the same issue and they resurface the rotors and the problem went away for a while.
Any suggestion or advise is greatly appreciated. thanks
Lexus did not perform the above TSIB. Last year, I had the same issue and they resurface the rotors and the problem went away for a while.
Any suggestion or advise is greatly appreciated. thanks
Last edited by Dinomon; 09-06-07 at 11:51 AM.
09-06-07, 04:11 PM
#2
Dinomon,
Rotors do wear out and need to be turned regularly. Usually one would turn rotors each 30-50k, depending on the driving style. There is no TSIB needed, this is a part of a regular maintenance.
- Andrey
Rotors do wear out and need to be turned regularly. Usually one would turn rotors each 30-50k, depending on the driving style. There is no TSIB needed, this is a part of a regular maintenance.
- Andrey
09-06-07, 06:07 PM
#5
Exactly right. Modern rotors are so thin that usually they can not be turned safely. If they can be turned, it is only once and the thinner the rotors are the more apt they are to warp again.
Lexus replaced my rotors and pads under a TSIB.
Lexus replaced my rotors and pads under a TSIB.
Last edited by jfelbab; 09-06-07 at 06:13 PM.
09-06-07, 06:54 PM
#7
I also question the cutting the rotor practice. It is commonly used but IMHO is an inferior solution as the thread starter had a warped rotor and cutting the rotor did little to prevent further warping in his driving style/condition. The more one cut, the less heat storing metal the rotor has to prevent further warping.
Lexus typically charge more on labor charge, even for simple procedures. As previous poster mentioned, I also prefer getting a new pair of new rotors and use an independent but trusted mechanic to do the installation.
Lexus typically charge more on labor charge, even for simple procedures. As previous poster mentioned, I also prefer getting a new pair of new rotors and use an independent but trusted mechanic to do the installation.
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09-06-07, 08:34 PM
#8
That is absolutely not true. Rotors can be turned until they reach the specified width. Under normal driving conditions, rotors should last for a long time and if they wrap too often, than there is might be a defect with braking system or rotors themselves, and only in that case rotoros can be replaced.
09-07-07, 05:07 AM
#9
That is absolutely not true. Rotors can be turned until they reach the specified width. Under normal driving conditions, rotors should last for a long time and if they wrap too often, than there is might be a defect with braking system or rotors themselves, and only in that case rotoros can be replaced.
If I remember correctly, most rotors even have the minimum diameter cast into them so that the person doing the lathe work doesn't have to look anything up.
Gary
09-07-07, 06:03 AM
#10
No, guys, what I sad was absolutely true. From someone who has miced a lot of of rotors you can cut a new rotor until you don't have enough material left. With newer vehicles, that usually means ONCE, if you have no scoring or significant warpage or parallelism issues.
New rotors have much less material thickness today than in prior years. If you have no scoring and no significant thickness variation you might get by with cutting a rotor but I've found them to only support one turning at best. If you check, the minimum thickness is stamped into the rotor. This minimum thickness is only a few hundreds of an inch less than the thickness of a new rotor.
At any rate rotors are much less expensive these days, You could count on paying $200+ a rotor in the old days. Now you can get high performance drilled and slotted rotors for around $200 a pair. OEM rotors usually can be had for around $100-$150 a pair. It will cost you $40-$50 a rotor just to have them turned. Many independent shops don't do a very good job turning rotors. They are too often cut with an old tool on a bench lathe that has seen better days and likely has it's own runout issues. These shops also seldom machine the rotors to the smoothness they should have. Many don't even compensate for runout. If you find a shop that has an on-car lathe you can up the prices to over the cost of new OEM rotors. New rotors are now so inexpensive that it's really a better solution to just replace them. For just a bit more than turning your old rotors you can replace them with new rotors and remember turned rotors are indeed more prone to warping.
Some manufacturers stamp a "machine to" thickness on the rotor. This allows for one and only one turning.
New rotors have much less material thickness today than in prior years. If you have no scoring and no significant thickness variation you might get by with cutting a rotor but I've found them to only support one turning at best. If you check, the minimum thickness is stamped into the rotor. This minimum thickness is only a few hundreds of an inch less than the thickness of a new rotor.
At any rate rotors are much less expensive these days, You could count on paying $200+ a rotor in the old days. Now you can get high performance drilled and slotted rotors for around $200 a pair. OEM rotors usually can be had for around $100-$150 a pair. It will cost you $40-$50 a rotor just to have them turned. Many independent shops don't do a very good job turning rotors. They are too often cut with an old tool on a bench lathe that has seen better days and likely has it's own runout issues. These shops also seldom machine the rotors to the smoothness they should have. Many don't even compensate for runout. If you find a shop that has an on-car lathe you can up the prices to over the cost of new OEM rotors. New rotors are now so inexpensive that it's really a better solution to just replace them. For just a bit more than turning your old rotors you can replace them with new rotors and remember turned rotors are indeed more prone to warping.
Some manufacturers stamp a "machine to" thickness on the rotor. This allows for one and only one turning.
09-07-07, 06:09 AM
#11
Out of Warranty
Last year after the TSB came out on the rotors, mine which had been pulsing badly for some time, but only on hard application at speeds over 50 mph finally started displaying the problem at lower speeds with regularity. The dealer replaced the front rotors (and pads) at 35K under warranty.
Now, a year later all is well, but I'm noticing the rotors don't LOOK like the older ones (and those in the rear). When they were installed they appeared to be a lighter color, and I thought that they would darken with use and age, but they really haven't. I wonder if there has been some change in the metallurgy somewhere between '03 and '06 that might account for this.
Anyone else notice this difference after having your rotors changed? My OEM's were sort of a dark gray-brown, where the new fronts are still sort of a silver-gray, both on the machined friction surface and the outer rim where the finish is "as cast".
Now, a year later all is well, but I'm noticing the rotors don't LOOK like the older ones (and those in the rear). When they were installed they appeared to be a lighter color, and I thought that they would darken with use and age, but they really haven't. I wonder if there has been some change in the metallurgy somewhere between '03 and '06 that might account for this.
Anyone else notice this difference after having your rotors changed? My OEM's were sort of a dark gray-brown, where the new fronts are still sort of a silver-gray, both on the machined friction surface and the outer rim where the finish is "as cast".
09-07-07, 06:47 AM
#12
Super Moderator
On my RX300, I have resurfaced my front rotors at least three times down here since getting them replaced in December 2004 in San Antonio. Inevitably, you will wind up resurfacing them again and again, and the period in between resurfacing (generally the time you start to notice vibration when braking) will get shorter and shorter. I burn my brakes really hard and will go through pads within about 6 to 8 months, even with fresh brake fluid, alignment, etc, which I am pretty religious on. Both environment (less oxygen and higher heat), traffic and racing have the most to do with it.
On my last set of front rotors, I could see at the dealer very deep burn marks (they were the OEM rotors from the factory) and my father even took a second look at it and we agreed with the Lexus tech that resurfacing was not an option (well you could, but they would just need to be replaced shortly anyway).
Eventually, I plan to switch over to some Rotora slotted rotors, but for now will play guinea pig and see how long I can get these to last.
On my last set of front rotors, I could see at the dealer very deep burn marks (they were the OEM rotors from the factory) and my father even took a second look at it and we agreed with the Lexus tech that resurfacing was not an option (well you could, but they would just need to be replaced shortly anyway).
Eventually, I plan to switch over to some Rotora slotted rotors, but for now will play guinea pig and see how long I can get these to last.
09-07-07, 08:33 AM
#15
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The issue with rotors is that they have to act as a heat sink and the more mass they have, the more effectively they can do this. When you cut the rotors, you remove material and diminish the rotor's ability to absorb as much heat. For most of us who don't do severe braking, turning the rotors (as long as they remain within tolerance) never presents a problem. For those whose rotors warped in the first place because of overheating, turning them will be a temporary solution. Because I don't like removing material from the rotors, I generally do not automatically turn them as part of a routine pad replacement. I only turn them if the surface looks bad or if I'm getting pedal pulsating symptoms. I have been replacing the rotors every other pad replacement and I think that's a very conservative approach to maintaining enough mass in the rotors so that they won't warp easily. The Germans appear to have gotten away from turning rotors altogether (Mercedes and BMW at least) and routinely replace rotors with pads. I think that is overkill and have gotten excellent results with pad replacement only. While some will tell you that it will take longer for the pads to break in, I have not found it to be a problem and the pads seem to be fully seated after a couple hundred miles.