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Old 12-04-2010, 12:19 PM
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03WhiteConv
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Default Brake pulse

I have read a bunch of info on the brake pulsing issue with stock brakes and pads and have a question about mine.

Base on my SOTP diagnostic, it feels like the rear brakes are the culprit. It's been going on for a long time now and I can make it go away for a while if I do some hard braking, seems to scrub them clean for a while. It always comes back.

I am wondering how many have had success with resurfacing or just scuffing the rotors with sand paper. I'd replace if I had to but would rather just fix the problem. These are oem replacements put on by GM at about 15k miles.

The car has about 40k miles now and the hardware looks to be in decent shape with good amount of pad.
Old 12-04-2010, 12:20 PM
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imavettegirl
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warped rotors.
Old 12-04-2010, 12:23 PM
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tommie
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do you feel a vibration when stopping?

if so, do you feel it in the steering wheel?

or does it feel more like it is in the body?

front brake rotors are usually the 1st to warp, they have more stopping force applied to them. If you are guessing, start with the front rotors. you can machine them, to resurface them... most auto parts have brake lathes, you could remove your rotors and have them turned....be sure to note which side they were removed from because the rotors vents are directional...(the rotor should be stamped with the wheel location)

if you are going through all of this work, now would be a great time to change your brake pads also....

remember to torque all of the bolts, and to keep the brake friction surfaces clean.
Old 12-04-2010, 12:29 PM
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03WhiteConv
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Originally Posted by imavettegirl
warped rotors.
I know that is normally where I would go too. Only thing is that a warped rotor will not stop pulsing after hard braking and you cannot feel this in the pedal, it's the whole car that pulses. Imagine the brakes pulling hard and then not so hard as the rotors rotate.

These pads and rotors are notorious for embedding some pad material on the rotor (almost like leaving and image of the pad on the rotor) and then pulsing due to the inconsistent surface of the rotor that is created. The pad material gets impregnated into the surface of the rotor and can be tough to remove.

I've had warped rotors before and this just does not feel the same. Hard to explain.
Old 12-04-2010, 12:34 PM
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03WhiteConv
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It is definitely the whole body pulsing, no feedback to the brake or steering wheel.

Just some background on me that might help. I'm pretty mechanically inclined and have always done my own brakes (25 yrs worth of brake jobs and dozens of cars). I am very comfortable with any repair that is needed.

Right now I am just trying to decide if I should just chuck the rotors and pads for new (and them properly bed them) or if it's worth my time to try and repair these.

Originally Posted by tommie
do you feel a vibration when stopping?

if so, do you feel it in the steering wheel?

or does it feel more like it is in the body?

front brake rotors are usually the 1st to warp, they have more stopping force applied to them. If you are guessing, start with the front rotors. you can machine them, to resurface them... most auto parts have brake lathes, you could remove your rotors and have them turned....be sure to note which side they were removed from because the rotors vents are directional...(the rotor should be stamped with the wheel location)

if you are going through all of this work, now would be a great time to change your brake pads also....

remember to torque all of the bolts, and to keep the brake friction surfaces clean.
Old 12-04-2010, 12:55 PM
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tommie
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Originally Posted by 03WhiteConv
It is definitely the whole body pulsing, no feedback to the brake or steering wheel.

Just some background on me that might help. I'm pretty mechanically inclined and have always done my own brakes (25 yrs worth of brake jobs and dozens of cars). I am very comfortable with any repair that is needed.

Right now I am just trying to decide if I should just chuck the rotors and pads for new (and them properly bed them) or if it's worth my time to try and repair these.
....I understand.... the cheapest thing you could do, would be to just r&r the rotors and machine them.... i also understand about the pad compounds .... i have been there many times.....

post up what you decided to do...and how it all worked out...
Old 12-04-2010, 02:00 PM
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Originally Posted by 03WhiteConv
I know that is normally where I would go too. Only thing is that a warped rotor will not stop pulsing after hard braking and you cannot feel this in the pedal, it's the whole car that pulses. Imagine the brakes pulling hard and then not so hard as the rotors rotate.

These pads and rotors are notorious for embedding some pad material on the rotor (almost like leaving and image of the pad on the rotor) and then pulsing due to the inconsistent surface of the rotor that is created. The pad material gets impregnated into the surface of the rotor and can be tough to remove.

I've had warped rotors before and this just does not feel the same. Hard to explain.
Had exactly the same experience with my '01. I wanted a "once and done" so I did new Napa rotors and pads and the issue is gone
Old 12-04-2010, 03:15 PM
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Dave68
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Here's the only permanent solution if you want to use the excellent OEM brake pads:

http://forums.corvetteforum.com/c5-g...ulsations.html
Old 12-07-2010, 12:50 PM
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03WhiteConv
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Originally Posted by Dave68
Here's the only permanent solution if you want to use the excellent OEM brake pads:

http://forums.corvetteforum.com/c5-g...ulsations.html
So are you using the aftermarket rotors with oem pads?
Old 12-07-2010, 02:21 PM
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Funny for me as when I got my 2001 in Feb2009 with 32,505 on it, for about the first 10,000 or so miles, when under hard deceleration/braking, I could feel a minor pulse in the pedal and after some more miles and time, it has completely gone away and I now have 62,800 miles on the car, 30,000 in just under 2 years.

I think all the braking and driving I have been doing helped whatever issue my stock setup had.

I do get a ton of dust on my OEM Thinspokes but I also get excellent braking.
Old 12-07-2010, 03:03 PM
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Originally Posted by 03WhiteConv
So are you using the aftermarket rotors with oem pads?
Yes - excellent braking that always has the feeling of fresh, perfectly parallel pads.
Old 12-07-2010, 07:15 PM
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guido7834
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Originally Posted by imavettegirl
warped rotors.
Mine does the same. No vibration in the front, which would be caused by warped rotors. So I don't think that is the issue.
Old 12-07-2010, 07:46 PM
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Bill Dearborn
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If it goes away with hard braking keep up the hard braking. I don't think you have any problem other than not using the brakes hard enough.

Bill
Old 12-07-2010, 08:32 PM
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Originally Posted by Bill Dearborn
If it goes away with hard braking keep up the hard braking. I don't think you have any problem other than not using the brakes hard enough.

Bill
Old 12-07-2010, 10:03 PM
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Originally Posted by Bill Dearborn
If it goes away with hard braking keep up the hard braking. I don't think you have any problem other than not using the brakes hard enough.

Bill
At first, I thought this to be true, but even after repeated, hard braking during one of our infamous "mountain runs", the pulsations would return after a couple of weeks. Slotted rotors permanently fixed the vexing pad-deposit problems once and for all.
Old 12-08-2010, 02:45 AM
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Originally Posted by Dave68
At first, I thought this to be true, but even after repeated, hard braking during one of our infamous "mountain runs", the pulsations would return after a couple of weeks. Slotted rotors permanently fixed the vexing pad-deposit problems once and for all.
I don't mean Hard braking at special events I mean all the time. You don't need to baby them when coming to a stop at a traffic light, stop sign, traffic jam, etc. Went 12 years using stock pads on the street and I never had any thumping on my 97 or 03. Just used the brakes the way they were designed to be used.

Bill

Last edited by Bill Dearborn; 12-08-2010 at 02:47 AM.
Old 12-08-2010, 10:16 AM
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The nice thing about slotted rotors is that you don't have to change your braking habits at all. The funny thing is that I brake the same way with all my cars and not one of the other cars has had the same problem. I came to the conclusion that if I wanted to continue to use the excellent OEM pads on the C5, I'd have to try something different. (without changing my 30+ year braking habits!)

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Old 12-10-2010, 12:32 PM
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03WhiteConv
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Originally Posted by Bill Dearborn
I don't mean Hard braking at special events I mean all the time. You don't need to baby them when coming to a stop at a traffic light, stop sign, traffic jam, etc. Went 12 years using stock pads on the street and I never had any thumping on my 97 or 03. Just used the brakes the way they were designed to be used.

Bill
I'm sure that you are correct on the hard braking but this car is a daily driver and it's just not practical to get on it that hard all of the time. Tough to explain but if I did that, I'd have a car in my trunk before too long.
Old 12-10-2010, 12:49 PM
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03WhiteConv
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Originally Posted by Dave68
The nice thing about slotted rotors is that you don't have to change your braking habits at all. The funny thing is that I brake the same way with all my cars and not one of the other cars has had the same problem. I came to the conclusion that if I wanted to continue to use the excellent OEM pads on the C5, I'd have to try something different. (without changing my 30+ year braking habits!)
I wonder what the difference would be with the GM upgraded perfromance rotors would be. I do like that rotor you're using but I was curious if I could find one that retained the stock look but not fall victim to the pulsing. Has GM ever changed the OEM rotor to solve this problem? If I bought new OEMs, I'm assiming that this issue would resurface?
Old 12-10-2010, 04:11 PM
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If the rotors are slotted, your pulsating brake pedal problems would be over. However, rotors that are not coated will rust very quickly. I'm not talking about the rotor faces, just the inner area between the faces.

And despite some folks' warnings about wearing down the pads too quickly, I've had the same pads with my PowerSlots for years now and there is plenty of life left in them.


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