# Secret to smooth brakes



## esoxlucios (Sep 17, 2009)

First, I want to [attempt to] dispel some notions about pulsating rotors:

Many people falsely believe that the cause of brake pulsation is "warped rotors." They believe their rotors got too hot, or they were warm and they drove through a puddle, or some other speculative theory.

Several years ago, there then appeared a Stoptech article (http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths) claiming that there is no such thing as warped rotors. The article claimed, instead, that brake pulsation is the result of pad transfer, where material from the pad fuses (welds) to the rotor when you come to a stop and leave the pedal pressed, and this creates a high spot that becomes "cementite," a material harder than the surrounding iron. The author claims that the high spot remains, while the rest of the rotor wears, and the pulsating gets worse over time. This article has made the rounds on forums for years, and has itself spawned a new urban legend.

In my opinion, the pad transfer theory is BS, just as much as the warped rotor.

Here's what I believe is really happening:

In the old days, when you would install a rotor, you were supposed to "index" the rotor. I.e., you were supposed to use a dial gauge (pictured below) to determine lateral runout (LRO) — anything more than .003" is too much. LRO is usually cause by an imperfect hub or hub surface. If you had LRO, you were supposed to rotate the rotor into different positions (based on the assumption that the rotor had some imperfection that could cancel out the hub's) and recheck until you had .003" or less.










When you have excessive LRO, the calipers float with it from side to side. Nevertheless, the slapping of the high spots against the pads eventually wears the rotor down more on that spot. After 5K to 10K miles, you have rotor thickness variation, which causes pulsation by forcing the pistons in and out as it travels over the high and low spots. This is resolved, of course, by turning the rotors or installing new rotors, but the problem always returns 5K to 10K miles later.

Nowadays, when you get new rotors installed (on any car) at TiresPlus or PepBoys or Firestone, imagine asking if your mechanic plans to index the rotors. They would look at you funny. Imagine asking if they planned to check the LRO on the new rotors with a dial caliper gauge. "A caliper what?," they might ask you. No, it's too easy to be parts-swappers instead of mechanics — they slap a new set of Chinese rotors on, and when you're back again in 10,000 miles, they're only too happy to slap another pair on, and suggest that you must ride the brakes too hot and "warped" them.

In any case, with our rotors, we can't index them — there is a set screw requiring the rotor to go on in only one position. So, what to do?

The solution is to use hub correction plates (pictured below) made by a NuCap, and sold under the brand "Brake Align." They are resold by Napa, Raybestos, and others, and you can even order them on Amazon. They come in correction thicknesses of .003", .006", and .009". Using your caliper gauge, when you find the high spot, you align the notch to the high spot, remount the rotors, and recheck for LRO. The part numbers for our cars (5x100 bolt pattern) are BA 104-03, BA 104-06, and BA 104-09.


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## ModsTTand (Jul 8, 2009)

*Thank you Sir*

Much appreciated for sharing your finds and knowledge. 

I'll put this info. in use .

:beer::thumbup:

UB


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## DerBassSpieler (May 12, 2008)

I've found that a common problem that leads to repeatedly warped rotors is something much simpler. Seized caliper sliders. Apparently, some people/places don't realize that checking and lubing these is necessary business. Doesn't take long to warp a rotor when you're only applying pressure to one side!  That being said, I'd like to check the run out on my calipers given your theory. Do you know if any of the chains rent dial gauges out or where to pick them up (fairly) cheap? Or is it possible to use normal measuring calipers for this purpose? -Steve


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## esoxlucios (Sep 17, 2009)

DerBassSpieler said:


> I've found that a common problem that leads to repeatedly warped rotors is something much simpler. Seized caliper sliders. Apparently, some people/places don't realize that checking and lubing these is necessary business. Doesn't take long to warp a rotor when you're only applying pressure to one side!
> That being said, I'd like to check the run out on my calipers given your theory. Do you know if any of the chains rent dial gauges out or where to pick them up (fairly) cheap? Or is it possible to use normal measuring calipers for this purpose?
> -Steve


You can get one from Harbor Freight for $15 + $25 for the flexible arm or magnetic holder.


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## DerBassSpieler (May 12, 2008)

HF to the rescue! Thanks


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## esoxlucios (Sep 17, 2009)

Here's a tutorial on the hub correction plates: http://www.youtube.com/watch?v=I5Mj_G5LIz8

And here's a tutorial on how to check LRO: http://www.youtube.com/watch?v=6SbWB2CNqio

Note, if your discs are slotted, like mine, you have to take your measurement at the last 1/8 inch of the outer edge of the rotor (otherwise, do it about a half inch from the edge).


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## Krissrock (Sep 10, 2005)

DerBassSpieler said:


> Doesn't take long to warp a rotor when you're only applying pressure to one side!
> -Steve


unless you have higher end oppsing piston calipers, that's almost all work. There's only 1 pison 1 side, applying the pressure... 

I do agree however, it's someting I aways relube wheneve I do breaks. but amazingly, whenever I do another person's breaks, they're as dry as a bone...

on other hand, motorcycle breaks and many opposing piston brake set ups don't have lubricated sliding pins or a system to keep them lubed.




i think the OP has a good idea here


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## lite1979 (Sep 9, 2005)

Thank for the post! I have a feeling that my siter-in-law has been suffering from this on her mkIV Golf for quite a while, at the cost of many sets of rotors..


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## ECS Tuning - Audi (Oct 12, 2009)

In most cases "wrapped rotors" or vibration is felt because pads are not properly bed. 

IMO those shims are a gimmick. 

When you do not properly bed your new pads to your rotors inconsistencies of pad material transfer to the face of the rotor. As the pad passes over the rotor this is what cause the pedal to pulsate. 

Majority of people who install new rotors and pads just drive on them and figure every day driving will bed them - or break them in. This is not the case. Pads need to be brought up to temperature then a few 60- almost complete stops need to be made. 

You want your rotor faces to have a slight blueish gray hue to them. This is how you know you have begun to transfer enough pad material to the face of the rotor. Having the proper amount of pad material evenly distributed across the face of the rotor will increase braking efficiency, reduce the possibly of squealing, and give you the maximum amount of rotor/pad life. 

I've been working on Audi's for over 10 years and have never had brakes that pulsate or had to use any sort of shim. 

Once in a while I will give the pads and rotors a good hard round of thresh hold braking to clear any rust or road debris that could get caught between the pad and rotor. This also helps keep pad material on the rotor face fresh.

Just like many parts on your vehicle brakes are a machine and need to be worked over once in a while to keep up the efficiency. You can go days without seeing hard braking if you do lots of engine braking or don't reach highway speeds. This can also start to wear away the transferred pad material because there's not enough pedal pressure or heat to keep transferring it. 

Not to mention that most calipers on Audi's are not fixed so they will self adjust so there is no need to index them. This is super old school when calipers were fixed and you needed very closer tolerances. 

Or if shims are used they are attached to the back of the brake pads them selves. 
Jason


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## speed51133! (Aug 5, 2002)

not to mention the rotor screw can just be removed.

does not serve any real purpose


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## mrbatavus (Nov 29, 2008)

on-car brake lathe
done


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## esoxlucios (Sep 17, 2009)

mrbatavus said:


> on-car brake lathe
> done


Can't find ANYONE in Twin Cities with one. Spent an afternoon calling around. Most shops never even heard of it (let alone rotor indexing).


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## esoxlucios (Sep 17, 2009)

ECS Tuning - Audi said:


> In most cases "wrapped rotors" or vibration is felt because pads are not properly bed.
> 
> IMO those shims are a gimmick.
> 
> ...


When you wrote the plates are a gimmick, I sure appreciated that you qualified it with "IMO." You never provided any rationale for the conclusory assertion. In addition to my own experience, if I had to choose between one person's opinion, and that of a major automotive manufacturer, I'd go with the latter: General Motors accorded “essential tool” status to the correction plates, mandating their use for all GM dealerships attempting to remedy LRO. See GM service bulletin No. 00-05-23-002A (re pulsation in the brake pedal or steering wheel during that recurs within 3,000 to 7,000 miles of having had the vehicle's brakes serviced. “Pulsation is the result of brake rotor thickness variation, causing the brake caliper piston to move in and out of the brake caliper housing . . . The major contributor to rotor thickness variation is excessive lateral runout of the rotor, causing the brake pads to wear the rotor over time.”).

In my experience, the pad transfer theory is BS. I've been advised on both my BMW and Audi that I could rectify this supposed pad transfer issue by doing threshold braking from 70 to 20mph seven times. I did it from 90 to 20 mph ten times, and in both cases, the pulsation not only didn't get better, it got worse. I drove my BMW down steep grades of I-70 in Colorado for miles attempting to wear the rotors clean. By the time I got to California, they were so bad, I had to replace them. On my Audi, which I've owned for nearly as long as you've been working on Audis, I got the pads hot enough to the point of smoking in an effort to eliminate the pulsation. The pulsation was the same, and gradually got worse right according to schedule. And I never ride the brakes and leave the pedal depressed at a stop (unless on a hill). I should add, the pulsation came on about 20K miles after installing the rotors, which seems to disprove the theory that the pads weren't probably bedded. In other words, I had no pulsation for the first 20K miles —but, guess what— I did have .009" of LRO on one side, and .006" on the other.

And, how in the heck are "shims . . . attached to the back of the brake pads them selves [sic.]" supposed to address LRO (wobbling of the rotor)?

The idea that floating calipers "self adjust," and therefore LRO need not be addressed by "old school" practices is folly: Why would anyone want their calipers to be oscillating back and forth thousands of times a minute by as much as .010" during braking, especially when, as pointed out by another member above, most shops don't follow yet another "old school" practice, which is to lube the caliper sliding pins? Not only that, if you have LRO, the whole wheel is wobbling, which I would assume would cause vibration, tire wear, and eventual damage to the wheel bearing. Why not correct that at the source (the hub)?

Finally, let me ask this: in another thread, you (i.e., ECS Tuning) wrote, "Our two-piece rotors have been subjected to thousands of miles of hard street use . . . They have also been subjected to scientific brutal stress testing at the track, performing countless high speed stops in quick succession. We have measured stopping distances and elevated rotor temperatures of over 1000*F for long sustained periods (to the point of rotor bluing and catching brake pads on fire) . . ."

This would suggest having rotor bluing is not good. Yet, above, you wrote, "You want your rotor faces to have a slight blueish gray hue to them." Really? According to an article published by autoZone (http://www.autozone.ro/autozone/rep...c15280213f5d&subtitle=bluing or heat checking), rotors that are blue need to be resurfaced. I'm confused.


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## ECS Tuning - Audi (Oct 12, 2009)

My mistake I should have said greyish-blue hue not bluish-grey. Below is a picture showing what I mean by the color. 










As you'll see a rotor that's been bedded compared to one that's fresh - the rotor that's had pads bedded has a greyish-blue look to it. 

Moving forward, I feel shims are a gimmick because they are just a band-aid for the issue. You state true facts about LRO but really if you are having that sort of issue I would rather just have the rotors turned to be positive I have a completely flat true surface. Like a wheel spacer, if both faces the shim touch, are not completely free of rust or road debris, the shim may not seat perfectly thus not giving you the proper "spacing" it's meant to provide. 

Another thing to consider is your tires. The shell casing on the tire could have a broken belt, feathering, cords showing, or just over all low tread. Many people forget about the friction coefficient of the tires also plays an important role in slowing the vehicle. 

You mentioned your pulsation happened after about 20k miles. If you're running a summer tire that's quite a stretch mileage wise - even a high wearing all season could begin to show signs of fatigue. I would definitely not over look this.

To support this I'll tell you about a first hand experience. My front tires were getting pretty low on my stock wheels right around the time I started to get a pulsation in my brake pedal. The tires were my main concern and I wanted to get them replaced ASAP as they were brutal in any sort of wet weather. Once I removed the tires sure enough the inside edge of my tires was completely bald and boarder line showing belts. The outside wall looked normal so this would go unnoticed unless you pulled the tires off regularly or had the vehicle on a lift to inspect. 

Once I put my new set of tires on I no longer had any brake pedal pulsation- I wasn't really expecting this to solve the issue as like most people I figured it was brake related. Since it solved the issue (and to this day I have no pulsation under any condition) I never further inspected it. I'll also mention I did not touch the brakes. I simply removed the wheels, installed new tires, then reinstalled the wheels. 

Also According to the article below "runout will not cause pulsation on vehicles with floating or sliding calipers and the caliper housing is free to move and the runout is not excessive" 

http://www.tirereview.com/Article/98305/solving_brake_pulsation_complaints_before_they_happen.aspx

This article also stats that "Runout is defined as the amount of lateral (side-to-side) movement of the rotor as it rotates 360 degrees. The specification is usually provided as “TIR” or “total indicated runout.” TIR is defined as the runout measured on the vehicle or installed runout. TIR includes all factors that can influence the amount of runout. Runout can be in the hub’s flange, the rotor or it can be caused by improper lug torque." 

So there are other factors that can play into how much runout there is not just the disc thickness or "Parallelism" 

"The main culprit of the chronic pulsation was variations in disc thickness, or parallelism. The two friction surfaces of a rotor are designed to be parallel to one another within a certain specification. The allowable tolerance is known as parallelism. It is also known as the rotor’s disc thickness variation, or DTV. In order for the pad to stay in contact with the rotor, the piston must extend or be pushed back into the housing as force is applied. This creates the pulsation in the pedal that is most noticeable to the driver" as stated in the article above as well. 

Jason


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## 20v master (May 7, 2009)

esoxlucios said:


> *I'm confused.*





esoxlucios said:


> In my experience, the pad transfer theory is BS.


We are well aware, as shown by the weird theories you come up with. After all your lessons on galvanic coupling and corrosion, you now think the phase state changes of iron are BS and don't affect ductility and hardness, which would cause uneven wear on the rotors? :banghead:


First, just because GM says it's required, that applies to THEIR vehicles and parts and most certainly doesn't mean it is required for all brands, makes, models, and manufacturer of brakes. Second, you can't "cure" or "eliminate pulsing" by repeatedly stopping from high speeds to the point of smoking pads. :screwy: The pad is the wear item. Yes the disc wears, but not at the same rate as the pad. Third, the phase state of the iron in the disc can be changed at any time, meaning that it may have happened 20K miles after you installed the discs, which would point to the hot spotting caused by your on the vehicle attempt at machining the rotors being the culprit, not the fact that you didn't bed the pads in initially. I've never had pulsing brakes since I've owned VW's and Audi's, and I've never used shims to install the rotors. I do know to bed in pads on initial install, and not to park a car with hot brakes with the e-brake on, as well as to move the car after a minute or two of cool down to get the hottest part of the now partially cooled disc out from the caliper. That all assumes spirited driving, so none of those practices are required on street driven vehicles that aren't driven aggressively. Good luck with your rotor shims if you feel they are required.


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## Chickenman35 (Jul 28, 2006)

esoxlucios said:


> First, I want to [attempt to] dispel some notions about pulsating rotors:
> 
> Many people falsely believe that the cause of brake pulsation is "warped rotors." They believe their rotors got too hot, or they were warm and they drove through a puddle, or some other speculative theory.
> 
> ...


I stopped reading when I got to the last sentence. I wasn't even going to reply, but the idea that Pad deposits do not happen and that Cermentite phase change is just a myth is just pure outright mis-information. :banghead:

To OP. *Do you have any idea who Carrol Smith is?* Your mysterious " Author" that you try to so quickly dismiss just happens to be one of the WORLD"S most renowned RACING ENGINEERS and has written many engineering papers and books for the Racing Industry.

http://en.wikipedia.org/wiki/Carroll_Smith

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

Cermentite phase change and pad to rotor deposit build up are a fact..not fiction. It is nothing new. Used to be called " Hot Spots " in the old days...and a rotor is essentially junk after these " Hot Spots " develop. These problems are noted by every single Brake manufacturer in the world. StopTech, Bendix, Raybestoes, Brembo, AP Racing..... to name just a few. Anyone who's worked in the Racing Industry, Big Rig trucking or Heavy transportation Industry knows all about these problems.

And Carrol Smith clearing addresses the issue of rotor run-out in one of the first paragraphs. :facepalm:



> ( Carrol Smith ): _" With one qualifier, presuming that the hub and wheel flange are flat and in good condition and that the wheel bolts or hat mounting hardware is in good condition, installed correctly and tightened uniformly and in the correct order to the recommended torque specification, in more than 40 years of professional racing, including the Shelby/Ford GT 40s – one of the most intense brake development program in history - I have never seen a warped brake disc."_


Read my signature below...that's all that needs to be said about this subject and thread.


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## esoxlucios (Sep 17, 2009)

20v master said:


> We are well aware, as shown by the weird theories you come up with . . . First, just because GM says it's required, that applies to THEIR vehicles and parts and most certainly doesn't mean it is required for all brands, makes, models, and manufacturer of brakes. Second, you can't "cure" or "eliminate pulsing" by repeatedly stopping from high speeds to the point of smoking pads. :screwy:


Weird theories? Well, if we can first get past your usual volley of insults (your MO for dealing with anyone you disagree with), the LRO as the cause of brake pulsation ain't MY theory, and much literature has been published on that subject.

Second, if you read my post, you would have read that I was ADVISED (by another) to cure the alleged pad transfer pulsation by multiple high speed threshold stops. That advice came from supposed experts in the industry who subscribe to your pad transfer theory (the one in the StopTech article). So, your criticism of this advice is misdirected.

Finally, I had no idea that GM uses some proprietary braking components of "THEIR" vehicles, such that it was improper to quote their bulletin. Maybe their rotors are made from a rhodium or kryptonite or some material than iron used in Audis and other cars. Who would have thought? :screwy:


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## Chickenman35 (Jul 28, 2006)

esoxlucios said:


> Can't find ANYONE in Twin Cities with one. Spent an afternoon calling around. Most shops never even heard of it (let alone rotor indexing).


On vehicle rotor machining is without a doubt the absolute BEST method for eliminating LRO. It is nothing new and many Dealerships were using it back in the mid-1980's. They were available with either cutters or grinding pads. This is similar to a system that we were using at Nissan in the late 1980's. 

http://www.youtube.com/watch?v=fD2ECRu6Jf4

Only the best shops use it now because:

1: The machinery is very expensive to buy.

2: It takes quite a lot of time to setup and run.

3: Independent Shops can make a lot more profit because they can sell cheap off shore new rotors at a 200 percent mark-up and pray that the Customer doesn't come back within the usual 90 day warranty period.

4: Dealership warranty programs have become more of a " Follow the flow chart, replace the following parts and don't ask questions " rather than true mechanical diagnostics and intelligent repair.


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## esoxlucios (Sep 17, 2009)

Chickenman35 said:


> I stopped reading when I got to the last sentence. I wasn't even going to reply, but the idea that Pad deposits do not happen and that Cermentite phase change is just a myth is just pure outright mis-information. :banghead:
> 
> To OP. *Do you have any idea who Carrol Smith is?* Your mysterious " Author" that you try to so quickly dismiss just happens to be one of the WORLD"S most renowned RACING ENGINEERS and has written many engineering papers and books for the Racing Industry.
> 
> ...


Can't read your signature — I'm using tapatalk.

No, I don't know who Carroll smith is. Should I? Do you know who the late Gordon Jennings is? I won't hold it against you.

The whole infallible Carroll Smith cementite theory is quite fascinating, except for one tiny problem: as stated in my post above, I don't ride the brakes, and I never hold the pedal down when I come to a stop, and I don't track the car. Same for my BMW (so, now, I'm talking about two cars). Also happened to my dodge diesel, which is manual shift (no holding the brakes at a stop). Now I'm up to three personal examples. So how, exactly, has this invisible ghostly mysterious pad material welded itself to my rotor that I should now have rotor pulsation? And why must I subscribe to this theory, as urged by the infallible Smith, as the real culprit, rather than LRO? Never mind, you stopped reading, already.


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## esoxlucios (Sep 17, 2009)

Chickenman35 said:


> On vehicle rotor machining is without a doubt the absolute BEST method for eliminating LRO. It is nothing new and many Dealerships were using it back in the mid-1980's. They were available with either cutters or grinding pads. This is similar to a system that we were using at Nissan in the late 1980's.
> 
> http://www.youtube.com/watch?v=fD2ECRu6Jf4
> 
> ...


The other issue is that my rotors (ECS Stage 2v2) are slotted. I read that you can't turn or machine slotted rotors, because the cutting blade skips and leaves high spots, and such rotors have to be "Blanchard" ground. I found one place, "Brake Supply Warehouse" that has such a grinder, but, of course, it's not on-car.


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## Chickenman35 (Jul 28, 2006)

> In my opinion, the pad transfer theory is BS, just as much as the warped rotor


That is the statement I am referring to. You are just 100% wrong there. Cermentite phase change ( hot spots ) and pad transfer are proven facts. You can argue with SAE ( Society of Automotive Engineers ) as well if you're so inclined.

BTW..Pad material transfer can occur under normal every day driving conditions. You don't have to cook the brakes. One of the worst instances I had of pad material transfer was ironically with Stop-Tech Hi-Performance pads. Absolutely horrible pulsation resulting from uneven pad transfer on Used rotors. The new material was not compatible with the old. That is why many Manufacturers of performance pads has a special bed-in surface treatment that is very aggressive. The purpose is to scour off the old pad depaosits and generate a fresh surface for the new pads to bed-in on. Bendix Titanium series and EBC are just two manufacturers that use this treatment. 

The rest of your information on alignment shims and the need for checking LRO is all well and good. However, there are better alternatives and if quality parts are used ( Not cheap off shore crap ) then the issue of LRO is seldom seen these day. Modern robotic machinery is just so accurate. 

And yes if you're trying to dismiss an Authors engineering studies ( not theories...proven facts over decades ) then you should know who you are talking about... IE: Carrol Smith = world renowned and recognized engineer... not some just some unknown Internet yobo. 

( And yes if I was going to dismiss some relevant Tech info on tuning Two Stroke motors I would sure as heck do some research into the background of the relevant Author. IE: The late Gorden Jennings , former Editor and long time columnist of Car and Driver and re-nowned motorcyclist enthusiast. I knew about him..but I did cheat by taking 5 minutes to refresh my memory with Wiki. )

Your whole dismissal of Pad material transfer and Cementite phase change fell apart right there.. That's all I'm disagreeing with :beer:


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## speed51133! (Aug 5, 2002)

opcorn:

love it


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## TToxic (Nov 15, 2008)

speed51133! said:


> opcorn:
> 
> love it


Oh yeah! :facepalm: Been doing brake jobs for 30+ years for many different classes of racing as well as daily hooptie drivers. Never used these shims, never had this pulsating or any of these problems. Criticizing ECS, fair enough personally I've spent many thousands with them over the years and never once an issue or poor experience. Talking smack on Stoptech and those affiliated with? Bold to say the least.


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## esoxlucios (Sep 17, 2009)

Chickenman35 said:


> That is the statement I am referring to. . . The rest of your information on alignment shims and the need for checking LRO is all well and good. . . Your whole dismissal of Pad material transfer and Cementite phase change fell apart right there.. That's all I'm disagreeing with :beer:


All I said was that *in my opinion* the theory is BS. That was a conclusion that —perhaps misguided or erroneous— I came to on my own based on my personal experiences. And, when I learned about the LRO and shims, and found excessive runout on my own car, I thought, "Ah ha, now I know what's going on. And now I know why I had to keep replacing rotors on the wife's BMW!"

I've read your posts, and CincyTT's and MadMax's around here long enough to recognize that you are an expert in these matters, and I defer to your judgment. But don't lose sight of the fact that there are few industries (or hobbies) fraught with as much speculation and theories and opinions as ours: consider the theories on the proper way to break in an engine, how to hone cylinders, how much back pressure is too much on a turbo car, the effect of exhaust scavenging, etc., etc., etc. Just spend a few minutes reading the posts on additives at Bob is the Oil Guy, and my point is obvious. No theory is sacrosanct. 

BTW, I've got these ECS Tuning Stage 2v2 rotors. Unfortunately, can get them turned anywhere and can't just throw away and replace with Napa blanks whenever a problem appears.


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## Chickenman35 (Jul 28, 2006)

esoxlucios said:


> The other issue is that my rotors (ECS Stage 2v2) are slotted. I read that you can't turn or machine slotted rotors, because the cutting blade skips and leaves high spots, and such rotors have to be "Blanchard" ground. I found one place, "Brake Supply Warehouse" that has such a grinder, but, of course, it's not on-car.


Slotted rotors can be turned on a standard brake lathe. You just have to be very, very careful when making the cuts.

I've done it myself with Slotted Coleman rotors. The trick is that you have take very, very small cuts ( .002" max ), run the Lathe at a " Fine " setting and make sure that you have proper anti-vibration elastic rings or pads attached. 

Most places won't do it because it takes a long time to do it this way and they are afraid of damaging their cutting tools. There are risks...but it can be done. It all depends on the shop and the skill of the Lathe operator. If you can find a brake lathe ( bench style ) in your area that uses rotating grinding pads then that will work even better.

The (Edit) two piece rotors are not an issue. Any decent shop should have centering arbors that will allow you to turn a two piece rotor on a Bench Lathe.

The other thing to check out is Big Rig or Bus brake repair shops. Buses in particular use disk brakes and shops that work on these have off vehicle Blanchard grinders. A front brake job with new rotors costs about $3,000 ...so if you can Blanchard grind the old rotors you can save a lot of money. A Big Rig brake shop " may " be able Blanchard grind your rotors if you talk nicely to them.

Here's what some big Greyhound service shops use:

http://www.dcm-tech.com/automotive-rebuilding-products/brake-rotor-grinders/


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## Chickenman35 (Jul 28, 2006)

Ultimate solution may be to ditch the ECS rotors and see if you can source them from a proper race supplier like Wilwood or Coleman. This will only work if ECS has specified a standard bolt pattern size. You'd have to take measurements of all of the rotor dimensions, paying particular attention to the bolt pattern and mount offset. 

If it is a standard bolt pattern, then you can easily order new slotted or non-slotted rotors from WilWood or Coleman etc. Wilwood or Coleman can even able to supply you rotors with a non-standard bolt pattern/size, although they will charge more.

They also have a large selection of rotor hats and can custom make hats to your specifications. The you can order a standard size Racing rotor with the proper alloys and at a reasonable price. 

Check out Circle Track suppliers like www.pitstopusa.com or https://www.lefthanderchassis.com/v2a/categoriesproducts.asp?idcategory=257


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## speed51133! (Aug 5, 2002)

this guy just decided to become an engineer overnight and educate all of us about metallurgy, fluid dynamics, finite particle analysis, heat treating, and design... all because he saw some pitting in his brakes....


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## G'D60 (Mar 11, 2002)

I can honestly say this is a great thread. little bickering here and there but the technical discussion is great and civil. well done lads!


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## esoxlucios (Sep 17, 2009)

speed51133! said:


> this guy just decided to become an engineer overnight and educate all of us about metallurgy, fluid dynamics, finite particle analysis, heat treating, and design... all because he saw some pitting in his brakes....


There are those that contribute something to this forum to help others, or ask provocative questions to further debate on a worthwhile topic. Members like MadMax, Chickenman, CincyTT, and many others.

Then there are those who contribute NOTHING, who only post insults, desultory criticism, ad hominem attacks, and mendacious commentary. We call them trolls. 

You are a dickish troll.


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## esoxlucios (Sep 17, 2009)

Chickenman35 said:


> Ultimate solution may be to ditch the ECS rotors and see if you can source them from a proper race supplier like Wilwood or Coleman. This will only work if ECS has specified a standard bolt pattern size. You'd have to take measurements of all of the rotor dimensions, paying particular attention to the bolt pattern and mount offset.
> 
> If it is a standard bolt pattern, then you can easily order new slotted or non-slotted rotors from WilWood or Coleman etc. Wilwood or Coleman can even able to supply you rotors with a non-standard bolt pattern/size, although they will charge more.
> 
> ...


Thanks much! I'll look into this. Bill at Diversified Cryogenics (a/k/a Frozen Rotors) here in MN said he can get Coleman to make both the friction rings and also get the hats made out of steel.


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## speed51133! (Aug 5, 2002)

esoxlucios said:


> There are those that contribute something to this forum to help others, or ask provocative questions to further debate on a worthwhile topic. Members like MadMax, Chickenman, CincyTT, and many others.
> 
> Then there are those who contribute NOTHING, who only post insults, desultory criticism, ad hominem attacks, and mendacious commentary. We call them trolls.
> 
> You are a dickish troll.


you left you THOSE that have no idea what they talk about, yet spend 15min on the internet to form a scientific opinion on metallurgy and engineering and then publicly BLAST a company. PERSONALLY (and I know I'm not alone here) you are WRONG about not only the majority of your conclusions, but also in the manner you blast the company. it is also laughable how you cherry pick supporting information for your conclusions, yet totally disregard opinions from people who work in the very fields you are dabbling in.

You are a fool

Sorry, I should just congratulate the community for supporting your ass-hattery. I've been there before, selling things to forum members just to have some douche customer think he is an expert on fluid dynamics and publically get blasted and face the torch burning crowds of the vortex.

Call me whatever. You may be trying to get to the bottom of your "issue" but the way and manner you go about it DEFINES DICKISHNESS.

carry on


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## esoxlucios (Sep 17, 2009)

speed51133! said:


> you left you THOSE that have no idea what they talk about, yet spend 15min on the internet to form a scientific opinion on metallurgy and engineering and then publicly BLAST a company. PERSONALLY (and I know I'm not alone here) you are WRONG about not only the majority of your conclusions, but also in the manner you blast the company. it is also laughable how you cherry pick supporting information for your conclusions, yet totally disregard opinions from people who work in the very fields you are dabbling in.
> 
> You are a fool
> 
> ...


This whole post proves my point. You're a troll, whose lengthy personal attacks on me does nothing to further the discussion, and only takes up space. In addition to being a troll, are you also a paid shill for ECS? You act like it.

I know the perfect forum for you: StockTwits. Useless comments welcome, and limited to 255 characters per post.


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## racin2redline (Sep 25, 2008)

Interesting.


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## lite1979 (Sep 9, 2005)

Well, since this is a forum, and not a technical journal reviewed by peers, I tend to mess up sometimes when I talk tech. It's still helpful when someone asks "Have you thought about it this way?" I've certainly posted things that were wrong, and I'm glad to have been corrected. When my car was overheating and I was chasing coolant leaks all over the car, it took a lot of convincing from members on dubsinthebuff.com to make me do a compression test and determine that I had a bad head gasket. If I could post the thread, I would, but it was a long and agonizing several days for me. I still appreciated the "check compressioin" post that was probably the first or second reply to the thread at the time. Was it too few words and too little explanation for me at the time? Yes, but I would figure that out through the course of the thread. 

That fact that we not only care about our own cars, but care about others' cars as well gives me a little hope for humanity. Proper diagnosis before replacing parts was probably the biggest problem I saw when I was on the mkIV forums six years ago, but there were so many people posting on there that logic got lost in a maze of smoke and mirrors because of misinformed replies. We have a small enough group here that we should all be able to see our mistakes and correct them, and keep driving our TTs for the next few decades. I plan to. :beer::beer::beer: (and a shot glass, too, because hey, biggest bar night in the USA tonight!) Canadian brethren, feel free to come over and watch us get $hitty!


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