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2002 Eldorado ETC & 1997 Seville STS
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116 Posts
Discussion Starter #1
My 97 Seville has 160,000 mi & it appears to have the original rotors.

The rotors appear to be in excellent condition – no scratches, grooves or any visible blemishes. :rolleyes:

I recently replaced rear brake pads & after 2,000 mi the rotors appear to be warped.

When I hit the brakes the car vibrated like a washing machine out of balance. :hmm:

Here are my questions:
1. How do you determine if the front or rear rotors need to be replaced?

2. Is it recommended to have the rotors machined flat?

3. Can you recommend an auto parts store to purchase new rotors?

Thanks!
Andy
 

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2006 XJ, 2000 Eldorado ESC--total loss :(
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1,180 Posts
It's fairly strightforward to check the rotors for lateral runout. You do need a dial indicator, though. I bought an old one with a magnetic base off eBay for $20 a while back. Basically you mount it to something solid, and touch it to the rotor face. As you rotate the rotor through 360 degrees you see how much runout you have. Any more than 0.005" and you will feel vibration (per GM spec), but less than that is preferable.

More often than not the problem is corrosion between the rotor and the hub surface. The hub flange has 3 large holes in it for access to the bearing bolts, and they let water get in between. It's likely that when you had the brakes done this was disturbed and now is causing vibration. What you can do is take off the rotors and clean both surfaces very well. Still helpful to have a dial gauge so you can find the high spots, but it's worth trying before buying anything.

If you need new rotors, I bought rear Delco rotors from RockAuto.com for something like $20 each. Not a bad price at all.



 

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1996 Eldorado
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2,814 Posts
The front will transmit vibs through the steering wheel & the rears you feel in the seat of your pants.

Do some E-brake stops to see if in fact the rear is the vibration source.
 

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08 cts 68k, 07 STS-V 15K, 97 Sts 160k
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302 Posts
I know my front rotors need to be replaced because when i put on the brakes the steering wheel shutters big time. I have had the rotors on my previous cars turned once but I would not have that done on rotors that have 126000 on them. Based on the mileage I would think you are due but I am going off of how I brake.
 

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2010 DTS
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87,941 Posts
Mileage means nothing. You can turn any rotor as long as it has the minimum thickness.
 

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08 cts 68k, 07 STS-V 15K, 97 Sts 160k
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302 Posts
Technically milage does not matter. But warp and wear do, which is indirectly related to milage. The worse the warp the more rotor needs to be turned off to get it true. If it ia a good shake it is not worth turning then just get new. As much as my brakes shake when the heat up I would not have them turned no matter how thick they are.
 

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2002 Eldorado ETC & 1997 Seville STS
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116 Posts
Discussion Starter #8
I understand the rear rotors look fine but may need a "skim cut to clean them up".

Can this be accomplished with 600 wet / dry sandpaper and a sanding block w/ the rotors on the car?

If I have to remove the rotors:
1. Is it cost effective to bring them to a machine shop for a light cut?
2. cut my looses & purchase new rotors
3. can the new brake pads only 2K be used again or do I need new?

Thanks
!:yup:
Andy
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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72,748 Posts
Can this be accomplished with 600 wet / dry sandpaper and a sanding block w/ the rotors on the car? Andy


NO !!!! Any machining on a rotor must be done on a brake rotor lathe, and there's a specific rotor thickness at which it will have to be discarded.
 

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08 cts 68k, 07 STS-V 15K, 97 Sts 160k
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302 Posts
I replaced my rotors and pads on my 97 last weekend. They vibrated like hell when they got hot. They looked ok on the outside but when I took them off the inside of the rotor had been turned making it much thinner than the outside of the rotor. Then back side of them looked like crap and felt like crap. I may have had a sticky caliper as well. I greased them up really good. They were a real BPITA to get off or break loose. I replaced pads and rotors on front and not it rides a lot better and stops like a dream $135 :thumbsup:plus my garage time FREE.
 

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2002 Eldorado ETC & 1997 Seville STS
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116 Posts
Discussion Starter #12
My local Auto Supply Store GM recommend Raybestos rotors & brake pads for my 97 STS.

He indicated they were as good as original GM equipment & significantly less expensive.

Example: Raybestor rear rotor $18 VS $38 for AC Delco.

Please provide examples of any experience you have had w/ Raybestos brake parts & rotors.

Thanks!
Andy
 

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97 ETC
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84 Posts
The only proper way to do rotors is a on car brake lathe,Pro Cut is the leader and every GM dealer has one. It will turn the rotor to the hub and be less then .001 run out...you can turn the rotor on a bench lathe but you are only making it true to the arbor on the lathe and not your hub..

GM wont even pay waranty on new cars if the dealer doesnt have a on car lathe,and Ford, Nissan and Chry.are the same also in that the on car lathe is a manditory shop equipment list.

Also not using a tourqe wrench or tourqe sticks can pull the rotor out also when using air guns..
 

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97 ETC
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84 Posts
Aslo Firestone stores through out the nation have a Pro Cut lathes...you could always call them and ask what they would charge to turn them on the car....
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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72,748 Posts
It's about $50 per wheel.

Get into www.ebcbrakes.com and find the links to the ProCut videos. Nifty piece of machinery.
 

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97 ETC
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84 Posts
Sub it is one of the best tools I have ever seen. I sold and serviced them for over 8 years....I could set the rack turb all four rotors on the car in less then 45 mins.It will usally do everything in one pass...up to .040 I have on large trucks cut .048...
 

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2002 Seville SLS, all black--261,000 miles
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934 Posts
At $50 per wheel, why not just get new ones? Couldn't you just be in need of a wheel balance, especially if there's any vibration in the steering wheel while driving a curve in the highway at speed?
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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72,748 Posts
At $50 per wheel, why not just get new ones? Couldn't you just be in need of a wheel balance, especially if there's any vibration in the steering wheel while driving a curve in the highway at speed?
Even with brand-new unused rotors a ProCut job guarantees silky-smooth braking. BUT you must follow the recommended rotor/pad break-in procedure.
 
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