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Discussion Starter #1
Finally got my front pads installed (Green Pad) about ten days ago. Rear pads were on backorder so they were installed yesterday. Anyway, about a week after the fronts were installed I started to get a steering wheel "shimmy" when hard brakes were applied. Shop told me that upon inspection the left rotor had warped and needed more turning to true it up. They suggested I contact Active Brakes to let them know that there might be a heat build-up problem with their pads and the stock GTO rotors ('05). Called them and was told there was "no way" that could happen. Had to be defective stock rotor or shop error when they first turned the rotors to install the new EBC Green pads. Told them bull****, this shop is the best in central Florida and I would take their word any day over a mfg. supplier. Kid then told me if I wanted to switch out the stock rotors he would get me a good price. I dunno, anyone else have an opinion on this? Seems to me that if it were a pad problem via heat build, etc. that both fronts would have warped the stock rotors...........btw, this car is never driven hard.:confused :confused


JET
 

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J.E.T. said:
Finally got my front pads installed (Green Pad) about ten days ago. Rear pads were on backorder so they were installed yesterday. Anyway, about a week after the fronts were installed I started to get a steering wheel "shimmy" when hard brakes were applied. Shop told me that upon inspection the left rotor had warped and needed more turning to true it up. They suggested I contact Active Brakes to let them know that there might be a heat build-up problem with their pads and the stock GTO rotors ('05). Called them and was told there was "no way" that could happen. Had to be defective stock rotor or shop error when they first turned the rotors to install the new EBC Green pads. Told them bull****, this shop is the best in central Florida and I would take their word any day over a mfg. supplier. Kid then told me if I wanted to switch out the stock rotors he would get me a good price. I dunno, anyone else have an opinion on this? Seems to me that if it were a pad problem via heat build, etc. that both fronts would have warped the stock rotors...........btw, this car is never driven hard.:confused :confused


JET
I hope he measured your rotors after he finished them. With newer cars it's the case, more often than not, that the rotors will be below discard/minimum thickness, after machining them. Plus you have to factor in what shape the rotors will be in throughout the expected service life of the newly installed pads. I can usually turn truck rotors, once, but not so with most cars. You may have even warped the rotor if you got it too hot during the break-in, w/o allowing them to cool down properly. Even old bits, or turning the rotors too fast will leave the rotors with a final finish that's not very smooth...a good source for too much friction/too much heat build-up.
 

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Discussion Starter #3
ModBoss2 said:
I hope he measured your rotors after he finished them. With newer cars it's the case, more often than not, that the rotors will be below discard/minimum thickness, after machining them. Plus you have to factor in what shape the rotors will be in throughout the expected service life of the newly installed pads. I can usually turn truck rotors, once, but not so with most cars. You may have even warped the rotor if you got it too hot during the break-in, w/o allowing them to cool down properly. Even old bits, or turning the rotors too fast will leave the rotors with a final finish that's not very smooth...a good source for too much friction/too much heat build-up.
You bet, these rotors only had 4K miles on them so he just had to do a light turn to insure they were true. Believe me, I barely touched the new brakes until there was almost 200-300 miles on them, well beyond the recommended 100 mile break-in period. We'll see how they work now.........

JET
 

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J.E.T. said:
You bet, these rotors only had 4K miles on them so he just had to do a light turn to insure they were true. Believe me, I barely touched the new brakes until there was almost 200-300 miles on them, well beyond the recommended 100 mile break-in period. We'll see how they work now.........

JET

If the tech had the right finish on your rotors, then that should eliminate him or the stock rotors as the source of the problem...but I still hope he measured it. One or two quick passes and one final pass on newish rotors should be within the limits; should be. Most of the times rotors can't even be turned, at all. Just normal pad wear [car's very first brake job] is usually more wear on the rotor than it can stand...it's already to the point that it can't safely be refinished.
 

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Discussion Starter #5
ModBoss2 said:
If the tech had the right finish on your rotors, then that should eliminate him or the stock rotors as the source of the problem...but I still hope he measured it. One or two quick passes and one final pass on newish rotors should be within the limits; should be. Most of the times rotors can't even be turned, at all. Just normal pad wear [car's very first brake job] is usually more wear on the rotor than it can stand...it's already to the point that it can't safely be refinished.

Picked it up today and everything is fine.........


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IMHO, someone overtorqued the lugnuts.

I've had it happen many times on our full size GM's after tire rotation. If the wheels are impacted on too tightly you will get an iritating vibration when hard braking. The rotors will definitely require a light trim, after you figure out why anyone would put lugnuts on tighter than spec. :confused
 

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bsmcall said:
IMHO, someone overtorqued the lugnuts.

I've had it happen many times on our full size GM's after tire rotation. If the wheels are impacted on too tightly you will get an iritating vibration when hard braking. The rotors will definitely require a light trim, after you figure out why anyone would put lugnuts on tighter than spec. :confused
Good point. I always use a torque wrench or torque sticks. A person that doesn't torque to specs is just lazy and/or thoughtless, imo.
 

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bsmcall said:
IMHO, someone overtorqued the lugnuts.

I've had it happen many times on our full size GM's after tire rotation. If the wheels are impacted on too tightly you will get an iritating vibration when hard braking. The rotors will definitely require a light trim, after you figure out why anyone would put lugnuts on tighter than spec. :confused
What is the correct torque specs for the lug nuts?
 

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Discussion Starter #10
Guys, this shop is not a bunch of kids. They're total pro's, believe me. This is the shop that all the dealers come to when they can't get alignment, tire balance or brakes figured out due to vibrations, etc. Been in business over 60 years. I totally trust these guys........

JET
 

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J.E.T. said:
Guys, this shop is not a bunch of kids. They're total pro's, believe me. This is the shop that all the dealers come to when they can't get alignment, tire balance or brakes figured out due to vibrations, etc. Been in business over 60 years. I totally trust these guys........

JET
You asked for input, and over-torqued lugnuts or machined rotors that were not turned at the right speed, wrong micro-finish, dull bits, etc were good suggestions. The problem could be blamed strictly on the new pads or the stock rotors not being up to the task of the pad swap, but those are more far-fetched than a mistake by a tech. I've been doing this for 23 years, with a group of guys that have been in the biz since the 60's. It only takes one bad seed being planted to give a business a bad image. Not saying that they're not pros, but I know about finding and keeping help that are as dedicated as the ones that built the business from the ground up.

Sorry if it made you mad.
 

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Discussion Starter #12
ModBoss2 said:
You asked for input, and over-torqued lugnuts or machined rotors that were not turned at the right speed, wrong micro-finish, dull bits, etc were good suggestions. The problem could be blamed strictly on the new pads or the stock rotors not being up to the task of the pad swap, but those are more far-fetched than a mistake by a tech. I've been doing this for 23 years, with a group of guys that have been in the biz since the 60's. It only takes one bad seed being planted to give a business a bad image. Not saying that they're not pros, but I know about finding and keeping help that are as dedicated as the ones that built the business from the ground up.

Sorry if it made you mad.
Not mad at all.......believe me. The shop consists of four guys, all in their 40's.......no kids or new hires at all. It's nice to deal with professionals on a one to one basis after dealing with dealerships who could care less.......thanks for your input.

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J.E.T. said:
Not mad at all.......believe me. The shop consists of four guys, all in their 40's.......no kids or new hires at all. It's nice to deal with professionals on a one to one basis after dealing with dealerships who could care less.......thanks for your input.

JET
Yeah, we stopped hiring in the late 80's
...and I'm guessing that new rotors solved your problem?
 

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Discussion Starter #14
ModBoss2 said:
Yeah, we stopped hiring in the late 80's
...and I'm guessing that new rotors solved your problem?
Nope, just re-turned the fronts again.......problem solved.

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J.E.T. said:
Nope, just re-turned the fronts again.......problem solved.

JET
Guess the *Green* pads weren't the problem afterall?

The stock rotors have been machined...twice?:eek:

The Aussie's must install really HD rotors from the factory...OR they're waaaaay under machined minimum by now.

b.t.w. What warped the machined rotors to start with...heat build up? If so, taking off extra material is just going to create a rotor that will heat up faster and will be unable to dissipate heat as well as it should, which can lead to brake fade and/or warped rotors. That's why measuring rotors before and after machining is a must. Steer clear of water puddles.

Edit: Maybe one of the pads were dragging? My factory C5 pad set had a couple of pads that needed a little filing on the backing to get them to slide smoothly. I would have had a problem.
 

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Discussion Starter #16
ModBoss2 said:
Guess the *Green* pads weren't the problem afterall?

The stock rotors have been machined...twice?:eek:

The Aussie's must install really HD rotors from the factory...OR they're waaaaay under machined minimum by now.

b.t.w. What warped the machined rotors to start with...heat build up? If so, taking off extra material is just going to create a rotor that will heat up faster and will be unable to dissipate heat as well as it should, which can lead to brake fade and/or warped rotors. That's why measuring rotors before and after machining is a must. Steer clear of water puddles.

Edit: Maybe one of the pads were dragging? My factory C5 pad set had a couple of pads that needed a little filing on the backing to get them to slide smoothly. I would have had a problem.
Just the problem rotor was turned again........VERY light so I'm not worried at all about the rotor life. We rotated the tires from front to back and now I have a slight vibration between 64 and 71 mph. Has to be another out of round tire.......these are new too, Goodyear F1's. Got 'em from Tire Rack and one was found bad right away......now it looks like another one has to be exchanged out. We'll get it right eventually.......believe me.

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one thing that I learned back several years ago when EBC started becoming big here in the US... The green stuff pads were originally designed for track day use OR cars 2500# or less. Given the weight of our cars, the red stuff pads appear to be more appropriate (and the minimum operating temp for the red stuff pads was right around 100 deg. F.

Now this may have all changed, but personally, I really liked the red pads, and will probably use them unless I go with a bigger upgrade :-D
 

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J.E.T. said:
Just the problem rotor was turned again........VERY light so I'm not worried at all about the rotor life. We rotated the tires from front to back and now I have a slight vibration between 64 and 71 mph. Has to be another out of round tire.......these are new too, Goodyear F1's. Got 'em from Tire Rack and one was found bad right away......now it looks like another one has to be exchanged out. We'll get it right eventually.......believe me.

JET
Turning rotors enough, twice, to correct warpage, twice, is considered light machining? Oh. If they're professionals of course it goes without saying that they made sure to measure the rotor closely, and installed it knowing that it passed the measurement specs. A shop owner can't be too careful when he puts his customers back out on the roads. You can't measure a rotor with a naked eye, that's why there's special tools for that, of course.

And before I condemned a high quality tire like that F1 I'd do a quick recalibration on by computerized balancer. Most modern ones have the ability to self-calibrate and load-test the tire for belt trueness.
 

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Discussion Starter #19
ModBoss2 said:
Turning rotors enough, twice, to correct warpage, twice, is considered light machining? Oh. If they're professionals of course it goes without saying that they made sure to measure the rotor closely, and installed it knowing that it passed the measurement specs. A shop owner can't be too careful when he puts his customers back out on the roads. You can't measure a rotor with a naked eye, that's why there's special tools for that, of course.

And before I condemned a high quality tire like that F1 I'd do a quick recalibration on by computerized balancer. Most modern ones have the ability to self-calibrate and load-test the tire for belt trueness.
No problem with the rotors........everything is fine. This shop does "on the car" tire balancing.........heads above ANY force balance machine. Right front was just slightly out of round causing a vibration from 64 to 71 mph only. This was the second tire out of the set of four that had to be replaced by Tire Rack. New tire coming, no problem.

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J.E.T. said:
No problem with the rotors........everything is fine. This shop does "on the car" tire balancing.........heads above ANY force balance machine. Right front was just slightly out of round causing a vibration from 64 to 71 mph only. This was the second tire out of the set of four that had to be replaced by Tire Rack. New tire coming, no problem.

JET
Good luck with all those problems that you keep encountering.

Off the car balancers can check for tire and wheel trueness and tread defects...and I personally prefer the off the car method to balance a wheel and tire. I want to know that it's perfectly balanced, that way if I'm still feeling a vibration I don't want to try and mask it with an on the car balancer, I want to trace it to the source and not be mislead...a bad drum, c/v axle, bearing, steering component, etc...plus, you're not forced to re-balance every time you rotate the tires.
 
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