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CUSTOMGAGT2000SEDAN
07-02-2009, 06:06 PM
because of vibrations at the front ,At 54,460 klms ( car had steel winter rims a good winter tires on at this klms period ) I had the 2007 grand prix 3.8 n/a front rotors replace at gm dealer .I also had them put on new pads and cleaned and lubed sliders etc etc.

Appears the rotors were just warned down enough to pass as warranty claim and sliders were seized a bit ,so inside pad on drivers and passenger brakes wore more then the outsides pads.
They put stock rotors on so they say , but they put ceramic pads on versus factory semi metallics. This all done under factory 60,000 klms warranty .



In between those 54,460 KLMS replacements / repairs and the the 60,000 klms , I would say 1 to 2,000 klms ,it next went in for front brake work again ,for eeking / creeking noise at front wheels likely the calipers again , that they even noticed also .

So at 60,000klms they re-cleaned and re-lubed the slides , back of pads and anything esle required. And we had them put back on good aluminium rims and summer tires .




Now at 60, 865 ( bit less during trip time ) we took it on a 2 hour trip up and back from a place call liverpool.

Every time we had to slow down from 80 , 90 , 100, 110 klms to take a turn off or break behind someone ,the steering wheel , pedals, front end bascially etc vibrated / pulsating like crazy , you could both feel and hear the vibration and pulsating.

So just talking to the service advisor , he said they are likely just going to turn down the rotors. I am thinking turning rotors down already that only have about 6,000 klms on them and that before the trip they were cleaned and lubed front and back.

Now from what I ever learned with my gagt and maybe other vehicles or listen to others , that if you turn down a rotors that vibrate like that you likely are just turn down a warped rotor. And by turning down warped rotors , that does not get rid of the warp , and it will come back.

This is the part number for the rotors # 18048698, do you guys think it is the part number for factory original equipment rotors for the 2007 GP 3.8 N/A 4 wheel disc.

ga2001gt532
07-05-2009, 01:23 PM
just go buy better rotors. most factory rotors suck

ltpats
07-05-2009, 06:54 PM
because of vibrations at the front ,At 54,460 klms ( car had steel winter rims a good winter tires on at this klms period ) I had the 2007 grand prix 3.8 n/a front rotors replace at gm dealer .I also had them put on new pads and cleaned and lubed sliders etc etc.

Appears the rotors were just warned down enough to pass as warranty claim and sliders were seized a bit ,so inside pad on drivers and passenger brakes wore more then the outsides pads.
They put stock rotors on so they say , but they put ceramic pads on versus factory semi metallics. This all done under factory 60,000 klms warranty .



In between those 54,460 KLMS replacements / repairs and the the 60,000 klms , I would say 1 to 2,000 klms ,it next went in for front brake work again ,for eeking / creeking noise at front wheels likely the calipers again , that they even noticed also .

So at 60,000klms they re-cleaned and re-lubed the slides , back of pads and anything esle required. And we had them put back on good aluminium rims and summer tires .




Now at 60, 865 ( bit less during trip time ) we took it on a 2 hour trip up and back from a place call liverpool.

Every time we had to slow down from 80 , 90 , 100, 110 klms to take a turn off or break behind someone ,the steering wheel , pedals, front end bascially etc vibrated / pulsating like crazy , you could both feel and hear the vibration and pulsating.

So just talking to the service advisor , he said they are likely just going to turn down the rotors. I am thinking turning rotors down already that only have about 6,000 klms on them and that before the trip they were cleaned and lubed front and back.

Now from what I ever learned with my gagt and maybe other vehicles or listen to others , that if you turn down a rotors that vibrate like that you likely are just turn down a warped rotor. And by turning down warped rotors , that does not get rid of the warp , and it will come back.

This is the part number for the rotors # 18048698, do you guys think it is the part number for factory original equipment rotors for the 2007 GP 3.8 N/A 4 wheel disc.

Turning a rotor does get rid of the warp (for a while) when you take material off the rotor during the turning process you thin the rotor which will make the rotor more prone to warping again. Replace the rotors with good quality rotors, Raybestos, Wagner.

Malaclypse
07-05-2009, 08:22 PM
What ltpats said about the removal of material is completely true. It reduces the resistance of the rotor to warpage because there's less material to dissapate the heat.

What I"m really questioning is why they replaced your brake pads with ceramic pads instead of factory style carbon metallic.

The ceramic pads are going to create more heat due to their composition and warp the rotors faster than factory pads would. Ceramic is a great insulator so all the heat is going into the rotors.

Factory rotors on most GM cars aren't the best design because they pretty much all warp. But for such a serious warpage problem to occour so quickly means there's something else going on. I'd suspect the pads.

Jhashwa
07-07-2009, 12:01 AM
Since they were first used on a few original equipment applications in 1985, friction materials that contain ceramic formulations have become recognized for their desirable blend of traits. These pads use ceramic compounds and copper fibers in place of the semi-metallic pad's steel fibers. This allows the ceramic pads to handle high brake temperatures with less heat fade, provide faster recovery after the stop, and generate less dust and wear on both the pads and rotors. And from a comfort standpoint, ceramic compounds provide much quieter braking because the ceramic compound helps dampen noise by generating a frequency beyond the human hearing range.

Another characteristic that makes ceramic materials attractive is the absence of noticeable dust. All brake pads produce dust as they wear. The ingredients in ceramic compounds produce a light colored dust that is much less noticeable and less likely to stick to the wheels. Consequently, wheels and tires maintain a cleaner appearance longer.

Ceramic pads meet or exceed all original equipment standards for durability, stopping distance and noise. According to durability tests, ceramic compounds extend brake life compared to most other semi-metallic and organic materials and outlast other premium pad materials by a significant margin - with no sacrifice in noise control, pad life or braking performance.

This is quite an improvement over organic and semi-metallic brake materials that typically sacrifice pad life to reduce noise, or vice versa.

From tirerack.com, ceramic pads are far better than semi metallic, and I have had nothing but good experience with them.

Alot of things can cause pulsations, the most common being over torqued wheels, overheated brakes (hitting a puddle when your brakes are hot will almost always cause them to warp, no matter how new the rotors are), over machined rotors as mentioned, dragging calipers, etc, etc. I have seen defective rotors out of the box, and some that go bad after a short while like yours.

ltpats
07-07-2009, 04:16 AM
From tirerack.com, ceramic pads are far better than semi metallic, and I have had nothing but good experience with them.

Alot of things can cause pulsations, the most common being over torqued wheels, overheated brakes (hitting a puddle when your brakes are hot will almost always cause them to warp, no matter how new the rotors are), over machined rotors as mentioned, dragging calipers, etc, etc. I have seen defective rotors out of the box, and some that go bad after a short while like yours.

I've been at this for over 26 years and have never used a torque wrench to tighten wheels, never had someone come back with pulsation due to over torqued wheels. Other than some odd ball reason pulsation is 99.9% of the time caused by warped rotors and for you 4 wheel disc people warped rear rotors will cause a pulsating pedal as well. When you buy new rotors make sure the parts store stores them on the shelf flat not on its side, this can and will warp them.

Jhashwa
07-07-2009, 08:17 PM
I was talking about pulsations and warpage as one and the same, but yeah warpage causes the pulsations.

I agree if you use common sense with the impact they will be fine, but if a tire guy pulls one or 2 lugs down to 200 ft lbs and the others to 80, it will pull the hub out of whack and cause warpage/pulsations.

Also drums cause far more pedal pulsations than discs. Ime

ltpats
07-08-2009, 04:17 AM
I was talking about pulsations and warpage as one and the same, but yeah warpage causes the pulsations.

I agree if you use common sense with the impact they will be fine, but if a tire guy pulls one or 2 lugs down to 200 ft lbs and the others to 80, it will pull the hub out of whack and cause warpage/pulsations.

Also drums cause far more pedal pulsations than discs. Ime

Never had a vehicle come in with the customer complaint of pedal pulsation that required turning the drums to fix it. Not to say that an out of round drum couldn't cause it but more times than not it's the rotors.

westerndragon
07-08-2009, 06:32 AM
sounds like your getting taken for a ride my friend....

tell them new rotors AND pads grease the hell out of the sliders and dont skip the anti-squeel stuff for the back side of the pads. and if they are going to put in ceramic pads get slotted rotors to pair up with them.
OE non slotted rotors with ceramic pads will add heat to the rotor and you'll just be back again ceramic is great stuff but that heat has to go somewhere.

[ChaosweaveR]
07-08-2009, 06:53 AM
First off, you got GM rotors, so it's no surprise to me that you have a warp problem with them. You just need a good quality aftermarket rotor. Hell, Autozone's Duralast rotor are much better than the GM factory ones. And it doesn't matter if the GP was "designed" to have semi-metallics. As long as you upgrade the rotors to a quality one, ceramics work wonderful. I have 21k on my ceramics, and they're a bit past halfway. They make almost no dust, no noise, and really got rid of majority of brake fade you got with semi-metallics.

lone_wolf025
07-08-2009, 04:18 PM
As I recall ceramics are actually less aggressive on the rotors than semi-mets. Last time I had ceramics I hated them...braking performance sucked ass.

[ChaosweaveR]
07-08-2009, 08:29 PM
As I recall ceramics are actually less aggressive on the rotors than semi-mets. Last time I had ceramics I hated them...braking performance sucked ass.

It was the opposite with me. There was quite the increase in bite switching to ceramics.