rotor problem?
- Thread starter triad
- Start date
No, something isn't right.... you should not feel that in any car you drive. "Is this normal?" Well...yes....these are normal signs of either loose or worn-out ball joints and/or wheel bearings. This is associated to cars with high miles. It may easily be warped brake rotors, bent or even loose wheels. It's hard to assess the problems without seeing or driving the vehicle itself, but it's a start.
Answering these questions may help narrow it down. Is it shaking or is it shuddering? How long have you had this problem? Was it a small problem that gradually became worse or was it something that happened overnight? Have you recently had your car in for any type of service? If so, was it done correctly? Keep this in mind... it is so important to torque down the wheel's lug nuts evenly, warped brake rotors are commonly caused by improper torquing. If you have aftermarket wheels, consider that the NSX originally, uses "convex seat" lug nuts vs. the more common, "tapered seat" style.
Answering these questions may help narrow it down. Is it shaking or is it shuddering? How long have you had this problem? Was it a small problem that gradually became worse or was it something that happened overnight? Have you recently had your car in for any type of service? If so, was it done correctly? Keep this in mind... it is so important to torque down the wheel's lug nuts evenly, warped brake rotors are commonly caused by improper torquing. If you have aftermarket wheels, consider that the NSX originally, uses "convex seat" lug nuts vs. the more common, "tapered seat" style.
I had the same problem after my first track event. I had not done any brake work on the car since I owned it (bought it 6 months before the track event I'm talking about). When I braked heavily before entering a turn off of a straight-away, the wheel vibrated heavily and things sounded and felt pretty darn bad. Before my next track event, I replaced my front rotors and the problem went away and has not returned (yet).
these are normal signs of either loose or worn-out ball joints and/or wheel bearings.
Then why does it go away when you replace the rotors?
It may easily be warped brake rotors
When brake rotors are warped, they shudder all the time, not just when they are very hot.
bent or even loose wheels
Then why does it go away when you replace the rotors?
it is so important to torque down the wheel's lug nuts evenly, warped brake rotors are commonly caused by improper torquing.
Except that these aren't warped (see above) and they happen even when the lug nuts are torqued properly (in my case, using a torque wrench that has been calibrated and found to be accurate).
Brake shudder is a fairly common problem in NSX's. I experienced it over and over for a long time. It would go away when I replaced the rotors. After a couple of track events, it would start to re-appear. After a couple more, it would be so severe that I would replace the rotors and start the cycle over again.
If this only happens to you once, I would just replace the rotors. If it happens again - likely only if you track your car - then I would consider some of the other steps I took (high-performance pads, high-performance rotors, high-performance fluid, and cooling ducts).
[This message has been edited by nsxtasy (edited 28 February 2002).]
Then why does it go away when you replace the rotors?
It may easily be warped brake rotors
When brake rotors are warped, they shudder all the time, not just when they are very hot.
bent or even loose wheels
Then why does it go away when you replace the rotors?
it is so important to torque down the wheel's lug nuts evenly, warped brake rotors are commonly caused by improper torquing.
Except that these aren't warped (see above) and they happen even when the lug nuts are torqued properly (in my case, using a torque wrench that has been calibrated and found to be accurate).
Brake shudder is a fairly common problem in NSX's. I experienced it over and over for a long time. It would go away when I replaced the rotors. After a couple of track events, it would start to re-appear. After a couple more, it would be so severe that I would replace the rotors and start the cycle over again.
If this only happens to you once, I would just replace the rotors. If it happens again - likely only if you track your car - then I would consider some of the other steps I took (high-performance pads, high-performance rotors, high-performance fluid, and cooling ducts).
[This message has been edited by nsxtasy (edited 28 February 2002).]
or the steps I took.
Brembo's
Brembo's
Hey Edo, your input here would be kindly appreciated...Originally the 2 pieces, the rotor and hat are loosly bolted together. When cold they rattle a bit but after heating them up the rattling supposedly goes away. This is understandably loosely fitted to compensate for heat expansion. I tried an earlier Brembo package from STILLEN which include the 2-pieces,hat and rotors. This package has the hat tightly bolted to the rotor.After track use they always become warped.After heavy braking or track use this eventually smoothens out untill cooling, then again, warped rotors. I have recently installed Brembo's own package on a clients car, which features "anti rattle clips".As found on the McLaren F1,the clips are on every other bolt that hold the hat and rotor together. They say this allows for heat expansion while reducing the cold rattling effect. My question is... which Brembo package do you have and what are your thoughts? Do you have any rattling or warping issues?Originally posted by Edo:
or the steps I took.
Brembo's
Thanks in advance...
The first place to start to diagnose your "brake shudder" is to replace the rotors, as keN sugegsted. If after installing brand new rotors, the car still shakes, then you have other problems...bearings, suspension parts, loose calipers, etc.
Get back to us with your results, and we can take it from there.
-Andie
------------------
andie w lin | vp marketing & product r&d
e: [email protected]
carbotech engineering
www.carbotecheng.com
Get back to us with your results, and we can take it from there.
-Andie
------------------
andie w lin | vp marketing & product r&d
e: [email protected]
carbotech engineering
www.carbotecheng.com
I have (had) the Brembo Lotus kit, which is the same as Brembo's own kit.
It had the Anti Rattle clip thingies on every other bolt and had the Rotor tightly mounted to the Hat.
As far as rattling problems went, I did not have any. As for warping, Yes I did have some warpage problems, but what I did was slightly have the mounting portion (The inner ring) machined down by less than 1 mm. This allows a bit of play in the Rotor and allows for it to expand slightly, giving it the "Floating Rotor" effect. I had no problems with it at all after that.
It had the Anti Rattle clip thingies on every other bolt and had the Rotor tightly mounted to the Hat.
As far as rattling problems went, I did not have any. As for warping, Yes I did have some warpage problems, but what I did was slightly have the mounting portion (The inner ring) machined down by less than 1 mm. This allows a bit of play in the Rotor and allows for it to expand slightly, giving it the "Floating Rotor" effect. I had no problems with it at all after that.
Now that the thread ha been sanitized, I'm not sure as to what you refer. I don't have a recurring problem with brakes on my NSX, but I have experienced the same symptoms. Contrary to popular practice and despite what some experts say, I spent $40 to have all four rotors turned and was pleased with the results. Granted, I haven't done any severe track events since then but did do a couple sessions while I gave the 510 a rest, and have put > 8k street miles on it without further problems. Also contrary to the claims of one particular expert, I have seen warped rotors. (I use the term warped to include significant measurable run-out not caused by pad wear.) All that said, it is conceivable that the actual cause in the case of my NSX was pad material deposits and I considered using emery cloth to clean them up. But since they were well out of speck in terms of run-out, spending $40 to cover both angles was a no-brainer.
I'll throw in my 2 cents. It's difficult to completely diagnose your problem from this little bit of information, but I cured my brake shudder problem by feshly turning my rotors and machining slots in them to vent the gasses.
I only experienced these problems at track events after exercising the brakes VERY hard. You didn't indicate whether or not the brakes were hot or cold at the time of the shudder. There are so many variables...
One of the things to look for are very tiny hair-line cracks on the braking surface of the rotors. It has been mentioned that these cause the rotors to expand and contract at different rates at different places on the rotor surface.
As I mentioned, turning and slotting the rotors helped me.
BTW, I'm glad to see the thread has been de-contented of all the vitriol.
[This message has been edited by ChopsJazz (edited 03 March 2002).]
I only experienced these problems at track events after exercising the brakes VERY hard. You didn't indicate whether or not the brakes were hot or cold at the time of the shudder. There are so many variables...
One of the things to look for are very tiny hair-line cracks on the braking surface of the rotors. It has been mentioned that these cause the rotors to expand and contract at different rates at different places on the rotor surface.
As I mentioned, turning and slotting the rotors helped me.
BTW, I'm glad to see the thread has been de-contented of all the vitriol.
[This message has been edited by ChopsJazz (edited 03 March 2002).]
Bruce, I understand you are from Tracy. I am with the NSXCA Sacramento Chapter. You must know Taz Harvey who came and helped us on 9/11 as an instructor at our Thunderhill track day.
If you want to pursue this thread ....., send me a private e-mail.
Hrant
98-T
[email protected]
Lud, thank you for for your response...
Hey Guys, again I appologize for the interuption.
sjs- like you were saying,"Contrary to popular practice and despite what some experts say,..." was my point, there are other possiblilites, somtimes just turning the rotors rather buying new ones solves the problem.In your case involving material deposits, you can try chamfering the leading edge of the pads(something I normally do on all pads)and/or with a cutting wheel, cut a slot down the center of the pad. This will also reduce the chances of build-up. In addition I understand the old spongy or soft brake
lines replaced with a more resistant stainless steel brake hoses helps.Also as Mark suggested I think is a good idea, regardless. These little things can make the biggest changes...Mark's post was in July Tech Section, I'll have to look again ...
Hrant...I not sure, but I have talked with Justin Hall a few times.Aren't you guys planning the 4/23 ThunderHill event? I'll e-mail you later...
[This message has been edited by Bruce (edited 04 March 2002).]
Hey Guys, again I appologize for the interuption.
sjs- like you were saying,"Contrary to popular practice and despite what some experts say,..." was my point, there are other possiblilites, somtimes just turning the rotors rather buying new ones solves the problem.In your case involving material deposits, you can try chamfering the leading edge of the pads(something I normally do on all pads)and/or with a cutting wheel, cut a slot down the center of the pad. This will also reduce the chances of build-up. In addition I understand the old spongy or soft brake
lines replaced with a more resistant stainless steel brake hoses helps.Also as Mark suggested I think is a good idea, regardless. These little things can make the biggest changes...Mark's post was in July Tech Section, I'll have to look again ...
Hrant...I not sure, but I have talked with Justin Hall a few times.Aren't you guys planning the 4/23 ThunderHill event? I'll e-mail you later...
[This message has been edited by Bruce (edited 04 March 2002).]
sjs-here it is...
NSXTech
Registered Member
Posts: 2
From: Phoenix, Az. USA
Registered: Jul 2001
posted 17 July 2001 17:07
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Any suggestions ?
A common cause for brake shudder that feels like warped disc's but is not warped disc's,
is / can be rust or other debris on the hub surface. Anyone who has watched me install new rotors has seen me wire wheel the hub surface before installing the new rotors. The hub surface is almost always rusty, and if you disturb it when removing the rotors and now have a piece of rust or other debris
causing the hub surface to be uneven, you will have a vibration. I would remove the rotors and check, and would also clean the rust while you are there.
As someone else said, it is very easy to put a dial indicator on the rotor and find the bad part. I use an indicator stand that is magnetic, and attach it to the strut.
Good Luck,
Mark
NSXTech
Registered Member
Posts: 2
From: Phoenix, Az. USA
Registered: Jul 2001
posted 17 July 2001 17:07
--------------------------------------------------------------------------------
Any suggestions ?
A common cause for brake shudder that feels like warped disc's but is not warped disc's,
is / can be rust or other debris on the hub surface. Anyone who has watched me install new rotors has seen me wire wheel the hub surface before installing the new rotors. The hub surface is almost always rusty, and if you disturb it when removing the rotors and now have a piece of rust or other debris
causing the hub surface to be uneven, you will have a vibration. I would remove the rotors and check, and would also clean the rust while you are there.
As someone else said, it is very easy to put a dial indicator on the rotor and find the bad part. I use an indicator stand that is magnetic, and attach it to the strut.
Good Luck,
Mark
Bruce,
Thanks, I've been doing the same for decades. I have a dial indicator w/magnetic stand, I bevel the edges of my pads, brush/chisel off the rust, etc. In the old days I need to nurse every mile I could out of each part, so I got pretty good at it.
All good advice for those new to DIY auto service.
Thanks, I've been doing the same for decades. I have a dial indicator w/magnetic stand, I bevel the edges of my pads, brush/chisel off the rust, etc. In the old days I need to nurse every mile I could out of each part, so I got pretty good at it.
All good advice for those new to DIY auto service.
Me too. Seriously.
there are other possiblilites, somtimes just turning the rotors rather buying new ones solves the problem.
That's true, sometimes it does. And it's also true that sometimes the rotors are indeed warped (with measurable runout), while there are other instances when they are not.
There are a couple of things to keep in mind when deciding whether to turn the rotors rather than buy new ones. Turned rotors are more susceptible to warping and/or shudder, so the problem may re-appear rather quickly, while it might not with new rotors. Depending on your situation, turning the rotors may be an easy and inexpensive fix that works out for your needs. This is particularly apt for the do-it-yourselfer, for whom it's typically no big deal to jack the car up, remove the rotors, take them out to get resurfaced for $20, and put them back on. If they work okay for a while, even if you have to do it again a couple months later, it's no big deal. On the other hand, if (for whatever reason) you are having a professional do the work on your car, you may be spending a fair amount of money to get them changed, and/or it may involve significant inconvenience in making the appointment and dropping off the car for service. Under those circumstances, it may be better to replace the rotors so as not to risk having to undergo the expense and inconvenience all over again soon. Another situation in which you may be better off replacing the rotors rather than turning them is if you're preparing for a track event, and you want to make sure your rotors will be good for the entire weekend, and you don't want to risk having to change the rotors at the track and losing track time as a result. OTOH, if you're not tracking your car at all, you may not need to do another hard 80-0 mph stop, and so turning the rotors may be just fine for your needs.
Keep in mind that the only downside of replacing the rotors vs turning them is cost, and that's relatively minor. Rotors are generally inexpensive (even aftermarket PowerSlot rotors are under $200 a front pair) so, depending on your situation, it may be worth spending a little bit more to ensure that it doesn't happen again for a while - again, depending on your particular situation.
The common denominator here is that, regardless of whether the vibration is caused by warping, or hot spots, or material deposits on the surface of the rotors, replacing the rotors will cure the problem. Turning the rotors may cure the problem but the cure may turn out to be short-lived.
There's an excellent discussion of this on Stoptech's website. Andrie previously posted a link to it on NSXprime here.
sjs, I find it interesting that you turned all four rotors. Was there measurable runout on the rear rotors? The reason I ask is that I have yet to run into anyone with the stock caliper setup who has had problems with the rear rotors. As to my own experience, which includes plenty of track usage, I have replaced ten sets of front rotors (some for shudder, some for cracking) without changing the rear rotors at all, and the rears still have plenty of thickness left.
I was wondering when will this comes up. Doesn't seem people pay that much attention to the post a while back. It has excellent discussion on brakes issues!
I would echo everything in the prior post from nsxtasy. Well said.
In my case, I'm a DIY type anyway and I'm not real patient about waiting for parts once I start a job. I had already ordered and received new pads before the shudder started (at a track event) because I knew they would be needed soon. So when I got home I jacked it up and checked the run-out, finding the fronts both pretty bad. (double the factory tolerance on one and nearly that on the other) The rears were both within tolerances but just barely, and since I was installing new pads it only made sense to resurface them as well regardless. (All were thick enough to leave recommended minimum after cutting) So, $40 and a couple hours later I was back on the road. I've done a Solo 1 event (full track autocross) and a couple regular track sessions plus thousands of street miles since then without further problems.
Getting back to what nsxtasy said, the DIY folks might find this worth a try, others may not. In my case it had nothing to do with money, just convenience and timing. (I would have spent WAY too much time researching which rotors to get!)
In my case, I'm a DIY type anyway and I'm not real patient about waiting for parts once I start a job. I had already ordered and received new pads before the shudder started (at a track event) because I knew they would be needed soon. So when I got home I jacked it up and checked the run-out, finding the fronts both pretty bad. (double the factory tolerance on one and nearly that on the other) The rears were both within tolerances but just barely, and since I was installing new pads it only made sense to resurface them as well regardless. (All were thick enough to leave recommended minimum after cutting) So, $40 and a couple hours later I was back on the road. I've done a Solo 1 event (full track autocross) and a couple regular track sessions plus thousands of street miles since then without further problems.
Getting back to what nsxtasy said, the DIY folks might find this worth a try, others may not. In my case it had nothing to do with money, just convenience and timing. (I would have spent WAY too much time researching which rotors to get!)
No one has mentioned it here yet, but I recall reading somewhere (I think it was in an old post on the topics of brakes), that you can have warped rotors that when measured cold are not warped, but when hot, they are. This phenomena works in a thermal runaway mode. The warping can begin small due to uneven heating. Then the small warpage changes the amount of braking you get on the cool vs. the warm part of the disc. Thereby further heating the hot areas more than the rest, causing more & more high temp warpage. But then when measured cold in the garage, you still have a non-warped rotor.
I believe that was posted to the e-mail lists a while ago by Bill Zachar. Unfortunately I don't think it made it into the FAQ. The theory is that spots on the rotors heat unevenly, so there are differences in thickness as they heat up.
I have no doubt that there are cases when a hot rotor measures differently in terms of run-out than when it's cold. I have typically driven mine hard just before pulling the wheels so they were at least quite warm.
However, many knowledgeable people will say that "warped" rotors are a myth entirely. (I guess they've never looked at rears after someone got them good and hot then parked with the handbrake on!) They insist that it is always hot-spots and/or material deposits on the rotors. Perhaps they don't consider measurable run-out well beyond factory specs to be "warped" (I do), or they don't believe that causes the symptoms attributed to warping. (on which they may be correct since turning the rotor also eliminates or reduces the other conditions.)
However, many knowledgeable people will say that "warped" rotors are a myth entirely. (I guess they've never looked at rears after someone got them good and hot then parked with the handbrake on!) They insist that it is always hot-spots and/or material deposits on the rotors. Perhaps they don't consider measurable run-out well beyond factory specs to be "warped" (I do), or they don't believe that causes the symptoms attributed to warping. (on which they may be correct since turning the rotor also eliminates or reduces the other conditions.)
I am familiar with many cases on the NSX (including mine) in which there is a very pronounced shaking when braking in situations where the brakes are very hot - either on the track (after a couple of warm-up laps) or on the street when doing a long, hard stop such as that described by triad above. In many of these cases, there is no noticeable shaking after the car sits for a couple hours and the brakes have a chance to cool off completely. What I am trying to convey here is that the difference in behavior between these situations is huge, not just what might be attributable to slight differences in measurement.
I do not claim that NSX rotors never warp, nor that warping is never the cause of vibration when braking. There are various reasons rotors can warp, including setting the parking brake when the rotors are hot (rear only), over-torquing the lug nuts, splashing water on hot rotors, etc.
The nice thing about replacing the front rotors is that it's not that expensive and it doesn't really matter whether it's hot spots or deposits or true warping; if the problem is due to any of these causes, it will be cured by replacing the rotors.
I do not claim that NSX rotors never warp, nor that warping is never the cause of vibration when braking. There are various reasons rotors can warp, including setting the parking brake when the rotors are hot (rear only), over-torquing the lug nuts, splashing water on hot rotors, etc.
The nice thing about replacing the front rotors is that it's not that expensive and it doesn't really matter whether it's hot spots or deposits or true warping; if the problem is due to any of these causes, it will be cured by replacing the rotors.
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