Need help from the experts

[Rickster]

OK. Have just spent the last 2 hours searching for new rotors for the STS and not really too much luck. The minimum I am looking for of course is OEM. Who makes the OEM rotors. That is my first question. Next point. Price. I will more than likly go to the dealer to get this done but WILL NOT pay any markup on parts. I do not mind paying for labour but refuse to be f**ked on parts. So what I need is some ideas on types of rotors (drilled, slotted, Brembo, ect) and some prices from your areas.

I have a high speed braking vibration that would shake the t*ts of a flat chested school girl.

I am going to replace the rotors no matter what. Do not need diagnostics on vibration issue thanks just the same.

Need input ASAP as I am going on a road trip this month.

Thanks in advance

Rickster

[Scotty]

Check these out

http://www.powerstoprotors.com/index.htm

http://www.autospecialty.com/

ALso check http://www.tirerack.com for Brembo, Frozen and Powerslot rotors

[Scotty]

edit mistake sorry

[KHE]

OK. Have just spent the last 2 hours searching for new rotors for the STS and not really too much luck. The minimum I am looking for of course is OEM. Who makes the OEM rotors. That is my first question. Next point. Price. I will more than likly go to the dealer to get this done but WILL NOT pay any markup on parts. I do not mind paying for labour but refuse to be f**ked on parts. So what I need is some ideas on types of rotors (drilled, slotted, Brembo, ect) and some prices from your areas.

I have a high speed braking vibration that would shake the t*ts of a flat chested school girl.

I am going to replace the rotors no matter what. Do not need diagnostics on vibration issue thanks just the same.

Need input ASAP as I am going on a road trip this month.

Thanks in advance

Rickster

What about having your rotors turned to clean them up? There should be plenty of thickness left to turn them.

[danbuc]

The OEM rotors are made by AC Delco. AC Delco also offers the Durastop rotrs, and pads which are ceramic pads, and cross drilled rotors I believe. Actually quite nice, from what I've heard. If you don't want to get f**ked on parts, then don;t go to the dealer. It's their job to mark up the price. If I were you, I would buy the rotors online, and find a good shop to do the work for you. That would be the best, and cheapest way to go about.

Once you get the prices from the dealer, check out these two sites, and look at their prices.

http://www.rockauto.com/

http://www.trademotion.com/partlocator/ind...m?siteid=213761

They are usually much cheaper than the dealer. Good Luck.

[Rickster]

I have actually had pretty good sucess on part prices with the dealer I deal with. If I bring in a price, they will beat it. Hope to hear more comments.

Thanks

Rickster

[JimD]

....

I have a high speed braking vibration that would shake the t*ts of a flat chested school girl.

I am going to replace the rotors no matter what. Do not need diagnostics on vibration issue thanks just the same.

....

Sounds like you are certain warped rotors are the problem.

Care to share your insight on identifying the root cause of the warped rotors?

Because if you do not address that issue, your 'new' rotors will suffer the same fate. No?

[Rickster]

Well here it is one year later and my rotors are warped again. These rotors were OEM and installed exactly one year ago. Only 20,000 or so kilometers have passed. This can't be right. Just had them turned yesterday and now they are fine. I am not hard on brakes. The OEM pads were replaced at the same time as the rotors. There is 60% left on them. I never smelt hot brakes over this period. Why should we buy OEM when it is cheap crap?

[Ranger]

Are you sure they were warped?

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

[Bill K]

Ranger, thanks for the link as I had changed computers and lost many good links such as the stoptech.

Thats some of the best brake info on the web.

[JimD]

Pay attention to the "PREVENTION" section of that link that Larry gave you. Pad bedding is an important step in a brake job and very few, if any, brake shops will do it.

[PAUL T]

On my 94 Concours, rust had accumulated around the outside edge and created a groove that caused my rotors to feel warped. After I had them turned just enough to knock the rust off they were fine.

[danbuc]

I think something should be said for "inadequite braking" as far as the OEM rotors (and brakes in general). It seems ot me, that for a car as large as the Seville...the brakes used onit are just not up to the task of continuous braking without excessive wear. I mean, the front rotors on these cars are used on abotu 12 other various GM vehicles, all lighter than ours. Everything from the Camaro and Impala, to Buicks and Pontiacs share this same set of rotors. The only difference mind you, is the caliper.

I understand the reasoning for this since it's "cost effective", but a 4000lb car should not be using the same rotors that a 3600lb car is using, especially when the heavier car develops much more power. The calipers used on our cars are not the most powerful either, and could certainly stand to be improved upon. The brakes are basically the same throughout the model lines, but they have to work much harder on our cars do to the increased weight of the vehicle. Cadillac really should have used a better brake system on these cars. While they do work fairly well, they are prone to excessive wear which sucks, because brakes are expensive.

If your looking for some better rotors (in particular the fronts) try searching for front rotos that fit the 2000 Camaro. There will be more selections. The rear rotors also fir the Buick Park Ave, Deville, and 2004 Bonneville GXP as well. Search for all these vehicle to find the maximum amoutn of parts you can.

On a side note, it seems as if the calipers used on the 03/04 Sevilles are shared by other vehicles liek the 00-03 Impala, a whole bunch of Buicks, the 00-03 Monte Carlo, and the 00-03 Bonnevilles. The y also seems to fit the 92-97 Sevilles and 92-02 Eldorados and a bunch of Devilles too.

I wonder why they suddenly went back to a previous design two years before the end of the model line. I also wonder whether or not the 03-04 Calipers would fit on the '98-02 models years Sevilles. The Impala and Monte Carlo are two cars that do have aftermarket brake systems available for them. It would be interestign to see if such a system would be adaptable not only to the Seville, but any Seville yera that shares the same brakes.

Anyway....just thought I'd throw out some ideas.

[Rickster]

I think something should be said for "inadequite braking" as far as the OEM rotors (and brakes in general). It seems ot me, that for a car as large as the Seville...the brakes used onit are just not up to the task of continuous braking without excessive wear. I mean, the front rotors on these cars are used on abotu 12 other various GM vehicles, all lighter than ours. Everything from the Camaro and Impala, to Buicks and Pontiacs share this same set of rotors. The only difference mind you, is the caliper.

I understand the reasoning for this since it's "cost effective", but a 4000lb car should not be using the same rotors that a 3600lb car is using, especially when the heavier car develops much more power. The calipers used on our cars are not the most powerful either, and could certainly stand to be improved upon. The brakes are basically the same throughout the model lines, but they have to work much harder on our cars do to the increased weight of the vehicle. Cadillac really should have used a better brake system on these cars. While they do work fairly well, they are prone to excessive wear which sucks, because brakes are expensive.

If your looking for some better rotors (in particular the fronts) try searching for front rotos that fit the 2000 Camaro. There will be more selections. The rear rotors also fir the Buick Park Ave, Deville, and 2004 Bonneville GXP as well. Search for all these vehicle to find the maximum amoutn of parts you can.

On a side note, it seems as if the calipers used on the 03/04 Sevilles are shared by other vehicles liek the 00-03 Impala, a whole bunch of Buicks, the 00-03 Monte Carlo, and the 00-03 Bonnevilles. The y also seems to fit the 92-97 Sevilles and 92-02 Eldorados and a bunch of Devilles too.

I wonder why they suddenly went back to a previous design two years before the end of the model line. I also wonder whether or not the 03-04 Calipers would fit on the '98-02 models years Sevilles. The Impala and Monte Carlo are two cars that do have aftermarket brake systems available for them. It would be interestign to see if such a system would be adaptable not only to the Seville, but any Seville yera that shares the same brakes.

Anyway....just thought I'd throw out some ideas.

Great ideas. That is exactly what my non dealer mechanic said. "If you feel you are not hard on your brakes, the car is probably under braked from design"

To be honest, the driving that I do do, probabaly involves more braking than the average drive, (Sea to Sky Highway), but this is not the first car I have owned while doing this comute. Not one of the other 1/2 dozen car owned ever had this problem.

I truly beleive GM has cheaped out.

More ranting later.

Rick

Are you sure they were warped?

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

Read this one with great interest a year ago. Good read and makes sense. But when my tool guy says there warped, I gotta beleive him.

Pay attention to the "PREVENTION" section of that link that Larry gave you. Pad bedding is an important step in a brake job and very few, if any, brake shops will do it.

Hey Jim,

Ya... good info. Thought I had done it proper a year ago but maybe not. Gad I love these cars but they piss me off.

Rick

[JimD]

It is safe enough to cut the rotors; just abide by the minimum thickness number cast into the inboard surface. A non-directional finish is preferred.

If this is a DIY job for installation, there are some extra steps you can take. Remove any trace of rust or other corrosion from all the clamping surfaces; hub, both sides of rotor, and inboard side of wheel using a wire brush and a little muscle. Take your time and get them clean.

Double check for a bent wheel. One bent wheel can affect all 4 rotors if your rotate your tires routinely.

I use a two-pass method to torque lug nuts; first pass at 75 lb/ft and 2nd pass at 100 lb/ft. Use a 1-3-5-2-4 lug nut sequence.

[justgreat]

my 90 seville had rotors on the front that i had turned twice!! and they were still within specs and stopped with no shudder from hiway speeds or less. the secret isn't the rotors or the pads: it's the bedding in of the pads to the rotors. do a google search for bedding in brake pads and you'll find a neat,precise explanation of why it's necessary and how to do it. it's kinda fun actually, just a but scary if you can't find a clear stretch of road...i did mine at 0300 on i95 in lower fairfield county...that was the only time there was any clear road and even then it was difficult.

a good delaership will actually bed the pads in while the car is on the lift with a machine they have.

there's a pretty good chance that without doing the bedding-in procedure, the first time you really stand on the brakes, they're cooked. and without turning the rotors you won't be able to get rid of the shudder.

jackg

06 sts6 on order

[BodybyFisher]

Rick, "warped" rotors are my favorite pet peeve.

First off, the front brakes will overheat if your rear brakes are not picking up their share of the work. If you have not serviced your rear brakes including bleeding them have that done. While the rear only pick up a small portion of the braking (say 30% as an example), if they don't pick up that share the front has to work harder and they overheat. If you have read the article that JimD referred you to from Stoptech, you know that overheating will cause brake material transfer and the shutter you are experiencing, heat is their #1 enemy. While a rotor could possibly be 'warped' it is more likely the transfer of brake material that is causing the shudder.

Your mechanic said they were warped? It is HIGHLY HIGHLY unlikely that he gets very DEEP into the analysis of your problem like we do here, he turned them, the pulsing stopped and he makes a BLANKET statement, they were WARPED... Easy for him. Did he use a dial indicator on the rotor surface like members here have done? Did he measure the thickness variation? Not likely...so his statement about warping was just that a statement. Ask him if he bled he entire system (front and rear) when he did the front brakes, I would be curious if he did. Many mechanics think that doing pads is a simple fast procedure, ITS NOT, when its done right, see #3 below, plus bleeding MUST be done at every brake job, PLUS I am a FIRM believer that you MUST do the front and the rear at the same time! To only do the fronts is looking for trouble!

Secondly, when I am in stop and go traffic or when I come to a hard stop I am very careful NOT to hold the brakes hard to hold the car at the red light... I also do not apply the parking brake when the brakes are hot. I am also careful not to drag my brakes creating unnecessary heat, and make sure my braking distance is as short as possible instead of dragging the brakes for a long time before a stop creating heat. Pay attention to your driving habits.

Third has your mechanic replaced the bushing kits and boots in your calipers? The bushing kit must be replaced every time you do your pads. See the photo below, your bushings are #2. The kit comes from GM/Cadillac, I doubt there is an aftermarket bushing/boot kit. The bushing stop the caliper from oscillating. Also, check your slider pins and slider holes to make sure they are not worn out of spec allowing the caliper to oscillate.

[scottshoe]

I agree with Bodybyfisher's last paragraph. I had the same problem, a huge "shake" under hard braking, not as bad at low speeds... put new rotors and ceramic pads all around, and the vibration didn't go away. I would bet that the caliper is seized on one of the pins it slides on, causing the pad to make contact on an angle and pulsating as it tries to grip the rotor. I cleaned my pins, and lubed the caliper and pins and the problem went away. Also make sure the lugs are torqued to 100 ft.lbs. as per factory spec.

As far as rotors, I bought some drilled and slotted ones (with zinc coating) off of E-bay for 1/4 of the price of "name brand" ones on the market. I am very happy with them, 10,000 miles so far and no issues. I have had to make many a panic stop in bumper to bumper traffic and still no complaints. The holes are even chamfered on the ones I bought.

[justgreat]

brake rotors do "warp". it may not be the most accurate word to describe what has happened but it's close enough to get the point across.

when the rotors are turned, it's simply taking off a very small amount of rotor material. more importantly, it cleans up the grooves and any pad material bonded onto to the braking surface.

if there has been high temperature usage of the brakes, without having the pads bedded into the rotors, there eventually will be problems with brake pedal pulsation.

bedding the brakes causes the transfer of the pad material to the rotors: that's why it is done. without bedding, the transfer is uneven; it occurs, as i said earlier, when the brakes are used in a heavy duty application, when you need them the most.

obviously, all other components in the brake system must be working up to snuff and any dragging pads is not good.

to spend the money on pads and rotors and NOT bed the pads is, in the long run, a waste of money, imo.

jackg

06 sts6 on order, just got back from the dealer...trying to get my owner's manual before the car comes in...william said maybe in a week, he'll have it for me...i'm psyched.

[BodybyFisher]

Let me repeat this for the millionth time. The term WARPED is used WRONG. To continue to use the term warped implies that something is WRONG with the ROTORS when that is NOT the case. Warped would mean it was like a CD ROM or ALBUM that was left in the sun, and that is NOT what is happening to the rotors.

The correct term is TV or thickness variation, and that is NOT warped. Can they be warped, sure but its RARE, its TV and Brake Material Transfer that is the problem causing grabbiness. To wit from the Stoptech article:

In fact every case of "warped brake disc" that I have investigated, whether on a racing car or a street car, has turned out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV) or run-out due to hot spotting that occurred at elevated temperatures.

As a matter of fact jackg is correct that the bedding process creates a uniform deposit of brake material on the rotor. But I want to add that its excessive HEAT that creates uncontrolled transfer of braking material. From Stoptech article:

There is no such thing as pure abrasive or pure adherent friction in braking. With many contemporary pad formulas, the pad material must be abrasive enough to keep the disc surface smooth and clean. As the material can cross the interface, the layer on the disc is constantly renewed and kept uniform - again until the temperature limit of the pad has been exceeded or if the pad and the disc have not been bedded-in completely or properly. In the latter case, if a uniform layer of pad material transferred onto the disc face has not been established during bedding or break-in, spot or uncontrolled transfer of the material can occur when operating at high temperatures.

It is the overheating of the rotor from 1) ineffective rear brakes, 2) mechanical problems (bushings or pins), or 3) continued hard braking or hard braking conditions or bad habits.......... that transfers the brake material unevenly causing TV... TV or thickness variation of the braking surface can be caused by brake material transfer in affect making the surface thicker and grabby or the pads dig in and rout out rotor material causing an uneven braking surface.

I am a firm believer that if the entire braking system is up to spec, including bleeding, bushings, parking brake adjustment, correct slider to slider hole dimensions, proper slider grease, and proper break in surface and bedding the OEM system will perform adequately.

That said, if you continue to have pulsing brakes, and you are 100% sure that your braking system does NOT have any deficiencies, worn out parts or installation mistakes, then drilled rotors might be the way to go. Its possible that your braking habits or roads travelled daily are exceeding the OEM rotors ability to dissipate heat. In that case, drilled rotors would help as they run cooler and TV due to overheating would be less of a problem.

[KHE]

brake rotors do "warp". it may not be the most accurate word to describe what has happened but it's close enough to get the point across.

when the rotors are turned, it's simply taking off a very small amount of rotor material. more importantly, it cleans up the grooves and any pad material bonded onto to the braking surface.

if there has been high temperature usage of the brakes, without having the pads bedded into the rotors, there eventually will be problems with brake pedal pulsation.

bedding the brakes causes the transfer of the pad material to the rotors: that's why it is done. without bedding, the transfer is uneven; it occurs, as i said earlier, when the brakes are used in a heavy duty application, when you need them the most.

obviously, all other components in the brake system must be working up to snuff and any dragging pads is not good.

to spend the money on pads and rotors and NOT bed the pads is, in the long run, a waste of money, imo.

I think the real cause of pedal vibration is uneven thickness of the rotors due to improper pad transfer or lack of bedding in the brakes. That situation gets labeled as "warped".

jackg

06 sts6 on order, just got back from the dealer...trying to get my owner's manual before the car comes in...william said maybe in a week, he'll have it for me...i'm psyched.

[scottshoe]

If you are looking for some "expert" advice, and not our interpretations and ideas, you should check out "stop tech"'s web-site. There is a very nice read about the #1 myth in brakes... warpage. It's a good read, and I am sure based on years of proven results and tests.

[BodybyFisher]

If you are looking for some "expert" advice, and not our interpretations and ideas, you should check out "stop tech"'s web-site. There is a very nice read about the #1 myth in brakes... warpage. It's a good read, and I am sure based on years of proven results and tests.

I love that whitepaper and if you look above I took quotes from it. Its an excellent article and prior to that did not understand the full inpact of heat induced shutter and TV..

[Rickster]

Good info guys. Appreciate it all. I really like the explanation on "warped" vs "VT" Makes sense. So... now that my rotors have been cleaned up, should I bed them again?

Rick

[JimD]

Yes, yes, yes.