got some brakin' shakin'

N8N · 06-24-2009, 03:54 PM

'08 Impala LS, bone stock (actually company car)

like the car so far, with the exception of one issue. When I brake from speed, the steering wheel shakes - a LOT. the odd thing is if I brake harder, the shake goes away, it only does it when I just ride the brakes a little, as if someone cut in front of me on the freeway and I want to back off a little bit (yeah, like that ever happens near DC.) The steering wheel moves a good inch or so if I take my hands off the wheel. Feels like warped rotors, right? Well I just had the car serviced and while they were changing the oil I had them balance and rotate the tires and cut the rotors. guess what - IT'S STILL THERE! If I'm braking at very slow speed, I can feel it then, too - the steering wheel doesn't shake, but I can feel the car jerk a little in time with the front wheels turning, like I'm pressing harder and lighter on the brake pedal (except I'm not.) Any ideas, other than just take it back and say "fix?"

I've only put a couple thousand miles on the car, I inherited it from another employee and it sat for a couple months in between. So I just assumed that the rotors were munged up from getting rusty while sitting but that does not seem to be the case. I don't think I drive it hard enough that I'm warping the rotors myself, and in any case, it did it the first time I had to stop from high speed after I picked it up from being serviced.

N8N · 07-01-2009, 04:25 PM

Follow up:

I finally got a chance to take the car back today, and the mechanic went for a ride with me and didn't even get the car up to speed, he just got up to maybe 30 MPH and rode the brakes a little, felt a slight pulsing, said "mmm-hmmm," and turned around and went back to the garage. This time they turned the REAR rotors. He said that Impalas were susceptible to rotor warpage, he had one himself and had had the same problem. I'm still trying to figure out how a warped rear rotor(s) could cause the steering wheel to shake but he claimed that you have to turn all four. (I guess this was a different guy than worked on the car last time.) I picked the car up this PM and at although I've only driven it home from work so far I'm giving it a thumbs up.

Now I have another question, how does the parking brake work on the newer Impalas, is that a little drum brake inside the rotor hat like a corvette or my old 944, or does the cable just pull the caliper shut like an old VW with rear discs? I'm wondering if setting the parking brake causes rear rotor warpage if the latter, in which case I will be more careful in the future about braking hard when I know I'm going to park soon (I can't avoid using the parking brake, my driveway slopes quite a bit.)

wedebrook · 07-01-2009, 04:45 PM

i cant say for certain on the 8th gen, but on the 7th gen, the parking brake is a drum in hat setup on the rear rotors. i would assume it would be similar on the 8th gen, but i have no first hand experience with them.

Buffman · 07-01-2009, 10:25 PM

more than likely mediocre pads from GM not bedded in properly...

[ UNEASY ] · 08-05-2009, 07:27 PM

To machine fronts only or all four is quite common. Often the warping is only on the front, but sometimes its on all four. Although it takes a little more time a good mechanic will do fronts first & rears only after a test drive to keep the cost down. The head mechanic at my work can often tell if its just fronts or not on a test drive before any work is done.

The pother thing to remember is that the metal in the disc disipates heat & excessive heat (or rapid cooling) is what warps discs. As the disc wears & it is machined to make it run true, there is less metal to do this job. What results is discs that warp faster each time they are machined.
For a daily this has to come down to ecconomics of machining verses replacement, for something that is a toy, or gets a hard time, machine the first time, then replace, for good braking.

sccastang · 08-07-2009, 07:17 AM

I had warpage on the front on my 08 Impala... I replaced with a set of EBC slotted and dimpled rotors and have had great results so far... the new rotors brake smooth as can be.

foodstampz · 08-22-2009, 05:16 AM

Quote:

Originally Posted by sccastang

I had warpage on the front on my 08 Impala... I replaced with a set of EBC slotted and dimpled rotors and have had great results so far... the new rotors brake smooth as can be.

Can you use those on a LS? I was looking at those somewhere online, I think for two it was like $250!
Also, is it possible to swamp out my LS suspension with SS suspension? Or can anyone recommend a nice shock because I think mine are getting warn out.

(I have a 06 LS 3.5 btw)

phileaglesfan · 10-05-2009, 05:44 PM

I have an 07 SS that had frequent brake problems. They resurfaced the rotors twice and wanted to resurface them the third time for $300. I ordered a set of slotted EBC Brakes for all 4. The front rotor started shaking. They installed new front rotors but said they couldn't "zero" out the right wheel runout. After talking to EBC brakes they said they should have used an on-car brake lathe (only a few auto places have it overall). Well I left the stock rotors on there for now to make sure there isn't another problem that GM wouldn't cover due to aftermarket brakes but I plan on getting the brake lathe done and install the EBC brakes on the front again. EBC was nice enough to send me a new set of front rotors.

Braking performance with the EBC brakes was great until the runout caused them to pulsate. Wet brake performance definitely improved over OEM.

As far as using them on an LS, I'm sure they have a part number for it. EBC has different pads though so make sure you get the right one. I got "redstuff" pads since the SS has over 300 hp. I don't know if I can post where I got them from on here so just PM me if you are interested and I'll tell you where I got them. I'm not sure if it is supporting vendor or not.

rkvette · 10-07-2009, 11:03 AM

my 2008 impala ss has a braking problem from high speed,pulsate and shaking... only have 20,000 miles and has done this from new... pads are still at 80%, so waiting till more wore down to replace.. i think i will have to go with ebc ? like sscastang/phileaglesfan... rkvette

N8N · 11-08-2009, 05:23 AM

follow up - I know, pretty late - I took it back and here they'd only cut the front rotors. They cut the rears and it feels much better. I feel like I can still feel a hint of rotor runout but nowhere near as bad as it was. Maybe the PO of the car abused it a little, or the brakes are just a little marginal?

nate

06-24-2009, 03:54 PM	#1 (permalink)
N8N Member Join Date: Mar 2009 Posts: 47	got some brakin' shakin' '08 Impala LS, bone stock (actually company car) like the car so far, with the exception of one issue. When I brake from speed, the steering wheel shakes - a LOT. the odd thing is if I brake harder, the shake goes away, it only does it when I just ride the brakes a little, as if someone cut in front of me on the freeway and I want to back off a little bit (yeah, like that ever happens near DC.) The steering wheel moves a good inch or so if I take my hands off the wheel. Feels like warped rotors, right? Well I just had the car serviced and while they were changing the oil I had them balance and rotate the tires and cut the rotors. guess what - IT'S STILL THERE! If I'm braking at very slow speed, I can feel it then, too - the steering wheel doesn't shake, but I can feel the car jerk a little in time with the front wheels turning, like I'm pressing harder and lighter on the brake pedal (except I'm not.) Any ideas, other than just take it back and say "fix?" I've only put a couple thousand miles on the car, I inherited it from another employee and it sat for a couple months in between. So I just assumed that the rotors were munged up from getting rusty while sitting but that does not seem to be the case. I don't think I drive it hard enough that I'm warping the rotors myself, and in any case, it did it the first time I had to stop from high speed after I picked it up from being serviced. __________________ Looking for Impala parts? Try The Chevy Impala SS Forums - Impala Store!

07-01-2009, 04:25 PM	#2 (permalink)
N8N Member Join Date: Mar 2009 Posts: 47	Follow up: I finally got a chance to take the car back today, and the mechanic went for a ride with me and didn't even get the car up to speed, he just got up to maybe 30 MPH and rode the brakes a little, felt a slight pulsing, said "mmm-hmmm," and turned around and went back to the garage. This time they turned the REAR rotors. He said that Impalas were susceptible to rotor warpage, he had one himself and had had the same problem. I'm still trying to figure out how a warped rear rotor(s) could cause the steering wheel to shake but he claimed that you have to turn all four. (I guess this was a different guy than worked on the car last time.) I picked the car up this PM and at although I've only driven it home from work so far I'm giving it a thumbs up. Now I have another question, how does the parking brake work on the newer Impalas, is that a little drum brake inside the rotor hat like a corvette or my old 944, or does the cable just pull the caliper shut like an old VW with rear discs? I'm wondering if setting the parking brake causes rear rotor warpage if the latter, in which case I will be more careful in the future about braking hard when I know I'm going to park soon (I can't avoid using the parking brake, my driveway slopes quite a bit.) __________________ Looking for Impala parts? Try The Chevy Impala SS Forums - Impala Store!

07-01-2009, 04:45 PM	#3 (permalink)
wedebrook Senior Member Join Date: Apr 2008 Location: Chillicothe, Ohio Posts: 606 View My Garage wedebrook	i cant say for certain on the 8th gen, but on the 7th gen, the parking brake is a drum in hat setup on the rear rotors. i would assume it would be similar on the 8th gen, but i have no first hand experience with them. __________________ I'm Old Gregg.

07-01-2009, 10:25 PM	#4 (permalink)
Buffman Senior Member Join Date: Nov 2008 Location: Michigan Posts: 191	more than likely mediocre pads from GM not bedded in properly... __________________ Burnout! Exhaust Video Misc Video New ^^ Gone 7/12/09, but not forgotten :(

08-05-2009, 07:27 PM	#5 (permalink)
[ UNEASY ] Member Join Date: Aug 2009 Location: Melbourne Australia Posts: 41 View My Garage [ UNEASY ]	To machine fronts only or all four is quite common. Often the warping is only on the front, but sometimes its on all four. Although it takes a little more time a good mechanic will do fronts first & rears only after a test drive to keep the cost down. The head mechanic at my work can often tell if its just fronts or not on a test drive before any work is done. The pother thing to remember is that the metal in the disc disipates heat & excessive heat (or rapid cooling) is what warps discs. As the disc wears & it is machined to make it run true, there is less metal to do this job. What results is discs that warp faster each time they are machined. For a daily this has to come down to ecconomics of machining verses replacement, for something that is a toy, or gets a hard time, machine the first time, then replace, for good braking. __________________ Looking for Impala parts? Try The Chevy Impala SS Forums - Impala Store!

08-07-2009, 07:17 AM	#6 (permalink)
sccastang Junior Member Join Date: Jul 2009 Location: Oswego, IL Posts: 20	I had warpage on the front on my 08 Impala... I replaced with a set of EBC slotted and dimpled rotors and have had great results so far... the new rotors brake smooth as can be. __________________ Looking for Impala parts? Try The Chevy Impala SS Forums - Impala Store!

10-05-2009, 05:44 PM	#8 (permalink)
phileaglesfan Junior Member Join Date: Oct 2009 Posts: 19	I have an 07 SS that had frequent brake problems. They resurfaced the rotors twice and wanted to resurface them the third time for $300. I ordered a set of slotted EBC Brakes for all 4. The front rotor started shaking. They installed new front rotors but said they couldn't "zero" out the right wheel runout. After talking to EBC brakes they said they should have used an on-car brake lathe (only a few auto places have it overall). Well I left the stock rotors on there for now to make sure there isn't another problem that GM wouldn't cover due to aftermarket brakes but I plan on getting the brake lathe done and install the EBC brakes on the front again. EBC was nice enough to send me a new set of front rotors. Braking performance with the EBC brakes was great until the runout caused them to pulsate. Wet brake performance definitely improved over OEM. As far as using them on an LS, I'm sure they have a part number for it. EBC has different pads though so make sure you get the right one. I got "redstuff" pads since the SS has over 300 hp. I don't know if I can post where I got them from on here so just PM me if you are interested and I'll tell you where I got them. I'm not sure if it is supporting vendor or not. __________________ Looking for Impala parts? Try The Chevy Impala SS Forums - Impala Store!

10-07-2009, 11:03 AM	#9 (permalink)
rkvette Member Join Date: Oct 2009 Posts: 34	my 2008 impala ss has a braking problem from high speed,pulsate and shaking... only have 20,000 miles and has done this from new... pads are still at 80%, so waiting till more wore down to replace.. i think i will have to go with ebc ? like sscastang/phileaglesfan... rkvette __________________ Looking for Impala parts? Try The Chevy Impala SS Forums - Impala Store!

11-08-2009, 05:23 AM	#10 (permalink)
N8N Member Join Date: Mar 2009 Posts: 47	follow up - I know, pretty late - I took it back and here they'd only cut the front rotors. They cut the rears and it feels much better. I feel like I can still feel a hint of rotor runout but nowhere near as bad as it was. Maybe the PO of the car abused it a little, or the brakes are just a little marginal? nate __________________ Looking for Impala parts? Try The Chevy Impala SS Forums - Impala Store!

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