Resurfacing Brake Rotors
May 20, 2004, 12:16 AM
#1
Resurfacing Brake Rotors
Since I am constantly reading posts where this question is asked I thought I would make a post devoted to it.
DO NOT resurface brake rotors just because you are replacing the pads. There is absolutely no reason. You shorten the rotor life, make it thinner so it does not hand the heat as well and spend money you should not be spending.
Almost every auto manufacturer has now come out and confimed that all of thier dealers should not be resurfacing rotors when brakes are done. It is only done to make money for the dealer.
Reasons for a rotor to be resurfaced.
1. Parallelism. The rotor is not true as it relates to the hub when it is on the vehicle. This is why they all recommend on car resurfacing.
2. Rotor scoring due to poor pad formulation, etc. Even then, GM's recommendation is to check the depth with a penny and if you can still see the top of Lincolns head then they are okay (believe it or not!)
If you would like to remove old pad transfer material from a rotor surface then you can use a 120 grit sandpaper to scuff up the surface. Excess pad transfer buildup can be removed without resurfacing. Many times it can be done by rebedding the pads. Roll-loc discs is also an option to clean up the surface of a rotor for pad transfer but even then I would go with a red (aluminum) disk, browns are just a bit to heavy.
I can honestly say that in the last 15 years I have never resurfaced a rotor on any of my 7 or so cars from all different manufacturers. Reason? Wheels should always be torqued with a torque wrench with no exceptions. I worked in a dealership for years and NO I didn't use one on customer cars because A) thatisn't the fast way when your flat rate B) If they start to pulsate I can just cut or replace them later (not my money but I make money doing it)
That is just the way it is. Don't think for a second that wheels get properly torqued at a dealership. Torque sticks only worked in a controlled situation in which the impact gun only puts out 250 ft lbs of torque. I've seen sticks broken by Impact guns because they are capable of a lot more then 250!
If you must have the wheels removed by a delaer or anyshop for that matter, request they use a torque wrench to reinstall the lugs and then when you get home, loosen all the lugs and retorque anyway.
DO NOT resurface brake rotors just because you are replacing the pads. There is absolutely no reason. You shorten the rotor life, make it thinner so it does not hand the heat as well and spend money you should not be spending.
Almost every auto manufacturer has now come out and confimed that all of thier dealers should not be resurfacing rotors when brakes are done. It is only done to make money for the dealer.
Reasons for a rotor to be resurfaced.
1. Parallelism. The rotor is not true as it relates to the hub when it is on the vehicle. This is why they all recommend on car resurfacing.
2. Rotor scoring due to poor pad formulation, etc. Even then, GM's recommendation is to check the depth with a penny and if you can still see the top of Lincolns head then they are okay (believe it or not!)
If you would like to remove old pad transfer material from a rotor surface then you can use a 120 grit sandpaper to scuff up the surface. Excess pad transfer buildup can be removed without resurfacing. Many times it can be done by rebedding the pads. Roll-loc discs is also an option to clean up the surface of a rotor for pad transfer but even then I would go with a red (aluminum) disk, browns are just a bit to heavy.
I can honestly say that in the last 15 years I have never resurfaced a rotor on any of my 7 or so cars from all different manufacturers. Reason? Wheels should always be torqued with a torque wrench with no exceptions. I worked in a dealership for years and NO I didn't use one on customer cars because A) thatisn't the fast way when your flat rate B) If they start to pulsate I can just cut or replace them later (not my money but I make money doing it)
That is just the way it is. Don't think for a second that wheels get properly torqued at a dealership. Torque sticks only worked in a controlled situation in which the impact gun only puts out 250 ft lbs of torque. I've seen sticks broken by Impact guns because they are capable of a lot more then 250!
If you must have the wheels removed by a delaer or anyshop for that matter, request they use a torque wrench to reinstall the lugs and then when you get home, loosen all the lugs and retorque anyway.
May 27, 2004, 12:25 PM
#3
I just went to the dealer and they said I need resurfaced brake rotors bc of the warping (grooves) in them. I am also paying $250 a piece for front pads, and $250 for rear totaling $500. He said that if I don't resurface the rotors it will wear down the brake pads faster and I'll eventually have to resurface the rotors anyway. Is he ripping me off?
DO NOT resurface brake rotors just because you are replacing the pads. There is absolutely no reason. You shorten the rotor life, make it thinner so it does not hand the heat as well and spend money you should not be spending.
Almost every auto manufacturer has now come out and confimed that all of thier dealers should not be resurfacing rotors when brakes are done. It is only done to make money for the dealer.
Reasons for a rotor to be resurfaced.
1. Parallelism. The rotor is not true as it relates to the hub when it is on the vehicle. This is why they all recommend on car resurfacing.
2. Rotor scoring due to poor pad formulation, etc. Even then, GM's recommendation is to check the depth with a penny and if you can still see the top of Lincolns head then they are okay (believe it or not!)
If you would like to remove old pad transfer material from a rotor surface then you can use a 120 grit sandpaper to scuff up the surface. Excess pad transfer buildup can be removed without resurfacing. Many times it can be done by rebedding the pads. Roll-loc discs is also an option to clean up the surface of a rotor for pad transfer but even then I would go with a red (aluminum) disk, browns are just a bit to heavy.
Originally Posted by timzcat
DO NOT resurface brake rotors just because you are replacing the pads. There is absolutely no reason. You shorten the rotor life, make it thinner so it does not hand the heat as well and spend money you should not be spending.
Almost every auto manufacturer has now come out and confimed that all of thier dealers should not be resurfacing rotors when brakes are done. It is only done to make money for the dealer.
Reasons for a rotor to be resurfaced.
1. Parallelism. The rotor is not true as it relates to the hub when it is on the vehicle. This is why they all recommend on car resurfacing.
2. Rotor scoring due to poor pad formulation, etc. Even then, GM's recommendation is to check the depth with a penny and if you can still see the top of Lincolns head then they are okay (believe it or not!)
If you would like to remove old pad transfer material from a rotor surface then you can use a 120 grit sandpaper to scuff up the surface. Excess pad transfer buildup can be removed without resurfacing. Many times it can be done by rebedding the pads. Roll-loc discs is also an option to clean up the surface of a rotor for pad transfer but even then I would go with a red (aluminum) disk, browns are just a bit to heavy.
May 27, 2004, 12:30 PM
#4
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^^^ you're getting hosed. Unless the evo uses like... ferodo race compound pads stock, which I dont think it does since you wouldn't be able to stop when your brakes are cold, don't replace your pads with stock ones. get some hawk HPs or something.
Last edited by Evoandy; May 27, 2004 at 12:33 PM.
May 27, 2004, 07:59 PM
#6
Originally Posted by LancerEVOmann
I just went to the dealer and they said I need resurfaced brake rotors bc of the warping (grooves) in them. I am also paying $250 a piece for front pads, and $250 for rear totaling $500. He said that if I don't resurface the rotors it will wear down the brake pads faster and I'll eventually have to resurface the rotors anyway. Is he ripping me off?
Jun 29, 2004, 12:02 PM
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My dealer raped me.
They told me it would not pass NYS inspection because of the rotors and pads
$900 later I got my NYS inspection sticker.
I took the rotors to 3 other mechanics and they laughed and asked why they did not pass!
Then the dealer wonders why I trash them on the JD Powers survey!
It is no wonder why Mitsubishi is $9 billion in the hole.
Another thing... The brakes had no pulsing or grinding.
They told me it would not pass NYS inspection because of the rotors and pads
$900 later I got my NYS inspection sticker.
I took the rotors to 3 other mechanics and they laughed and asked why they did not pass!
Then the dealer wonders why I trash them on the JD Powers survey!
It is no wonder why Mitsubishi is $9 billion in the hole.
Another thing... The brakes had no pulsing or grinding.
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Aug 4, 2004, 01:28 PM
#8
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Am I being ripped off??
Just got back from a mechanic. Bought a set of Ferodo DS2500 pads that I wanted them to install and I've been having a pulsation in the steering wheel so i asked them to resurface the rotors. The owner of the shop told me that the rotors could be resurfaced, but they would just warp again in less than a month and that I needed all 4 new rotors!?!?! Something about the "rotor core" got too hot... Is this BS or is he shooting straight with me? I really don't have an extra $900 in the budget for new rotors.
Aug 4, 2004, 02:01 PM
#9
It depends on "how warped" they actually are.. But overheating a rotor will warp them (usually if they overheat unevenly)
I've actually always done the same thing, I don't resurface unless there's a serious pulsation or shimmy.. Generally I've already gotten 30k+ on the rotors and I've replaced them.. On this car their much more expensive so I'd probably resurface them if they pulsated slightly.
I've actually always done the same thing, I don't resurface unless there's a serious pulsation or shimmy.. Generally I've already gotten 30k+ on the rotors and I've replaced them.. On this car their much more expensive so I'd probably resurface them if they pulsated slightly.
Aug 4, 2004, 06:09 PM
#10
Will resurfacing get rid of the pulsing? Mine just started pulsing a little bit at the end of the stock pads life (23k miles). I'm going to put on new front pads, but was wondering if I should resurface. I have always put my wheels on without a torque wrench, but by hand. If you do torque them funny, what will fix that issue if it is causing the pulsing?
Aug 8, 2004, 05:15 PM
#12
turning is resurfacing.....
If you think the rotors have excessive runout then turning them may have them hold on for a bit longer but the runout will likely return as cast iron has a memory of sorts.
However most 'warped' rotors are actually exhibiting too much DTV (disc thickness variation) as a result of uneven pad material deposits which generally results from poor bedding, poor 'cool down' after hard use, or clamping a hot pad on a hot rotor.
As mentioned - rebedding the pads can often resolve this issue and it may take a few tries to 'smooth' it out. Otherwise go the sandpaper route...as a last resort turn just enough to clean up the surface.
It only takes a small amount of uneven material buildup to feel a pulsing pedal.....if the pads hits a 'thicker spot' each time the rotor goes around then all four pistons get pushed back in and thus fluid is sent back up the lines through the MC to your foot. .0005" is enough to feel
Runout on the other hand, pushes one side of the calipers pistons back in but lets the other side come out thus creating fluid movement only inside the caliper. This would only become an issue if the pistons were all moving back and forth so much (.003-.005 a magnitude higher) that you could feel it - i would guess in the steering and car more than in th ebrake pedal.
my .02
If you think the rotors have excessive runout then turning them may have them hold on for a bit longer but the runout will likely return as cast iron has a memory of sorts.
However most 'warped' rotors are actually exhibiting too much DTV (disc thickness variation) as a result of uneven pad material deposits which generally results from poor bedding, poor 'cool down' after hard use, or clamping a hot pad on a hot rotor.
As mentioned - rebedding the pads can often resolve this issue and it may take a few tries to 'smooth' it out. Otherwise go the sandpaper route...as a last resort turn just enough to clean up the surface.
It only takes a small amount of uneven material buildup to feel a pulsing pedal.....if the pads hits a 'thicker spot' each time the rotor goes around then all four pistons get pushed back in and thus fluid is sent back up the lines through the MC to your foot. .0005" is enough to feel
Runout on the other hand, pushes one side of the calipers pistons back in but lets the other side come out thus creating fluid movement only inside the caliper. This would only become an issue if the pistons were all moving back and forth so much (.003-.005 a magnitude higher) that you could feel it - i would guess in the steering and car more than in th ebrake pedal.
my .02
Last edited by infantsam; Aug 8, 2004 at 05:27 PM.
Aug 8, 2004, 05:24 PM
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Originally Posted by sir lurks alot
Will resurfacing get rid of the pulsing? Mine just started pulsing a little bit at the end of the stock pads life (23k miles). I'm going to put on new front pads, but was wondering if I should resurface. I have always put my wheels on without a torque wrench, but by hand. If you do torque them funny, what will fix that issue if it is causing the pulsing?
Aug 10, 2004, 09:37 PM
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I had to resurface my stock rotors after only 3K of driving with proper break in and never abused nor ever washed when rotors are cold etc...
Under warranty of course but now the car has 6K and the shimmering has returned. I am sick of dealing with Mitsubishi.. they gave me a runaround, had to talk to the service manager, then talked to the regional person... blah blah... three trips later they shaved off 2-3 times more wear on my rotors than I did in 3K. I was ticked off!!
I'm thinking of replacing the pads and have the rotor turned by the local shop. I still have a lot of life life on my rotor.
New rotor nominal thickness is 32.0 mm Minimum thickness is 29.8 mm... When I took my car in they measured the thickness in 8 locations at 45 degrees increment the LH had (31.91, 31.91,31,90,31.89 mm ... ) the RH had (31.89,31.88,31.89,31.87...) After shaving my rotors my LH had 31.74mm left and RH had 31.66mm left.
I felt that they shaved the life off my rotors at my expense and didn't fix my problem. I really think I have bad pads because the problem is back!
They should've at least measured the thickness of the rotors and see how much life was left. When they do that, that's like having a little oil leak on your engine and recommend you to replace the entire motor.
From my experience, the rear rotors RARELY warp, if replacement is warranted it's usually just the front rotors.
Sorry to hijack your thread ... but absolutely, I agree with not resurfacing rotors just because pads were replaced. And spend $900 on rotors and pads because of brake shimmers... that dealership service manager should be SHOT!
Under warranty of course but now the car has 6K and the shimmering has returned. I am sick of dealing with Mitsubishi.. they gave me a runaround, had to talk to the service manager, then talked to the regional person... blah blah... three trips later they shaved off 2-3 times more wear on my rotors than I did in 3K. I was ticked off!!
I'm thinking of replacing the pads and have the rotor turned by the local shop. I still have a lot of life life on my rotor.
New rotor nominal thickness is 32.0 mm Minimum thickness is 29.8 mm... When I took my car in they measured the thickness in 8 locations at 45 degrees increment the LH had (31.91, 31.91,31,90,31.89 mm ... ) the RH had (31.89,31.88,31.89,31.87...) After shaving my rotors my LH had 31.74mm left and RH had 31.66mm left.
I felt that they shaved the life off my rotors at my expense and didn't fix my problem. I really think I have bad pads because the problem is back!
They should've at least measured the thickness of the rotors and see how much life was left. When they do that, that's like having a little oil leak on your engine and recommend you to replace the entire motor.
From my experience, the rear rotors RARELY warp, if replacement is warranted it's usually just the front rotors.
Sorry to hijack your thread ... but absolutely, I agree with not resurfacing rotors just because pads were replaced. And spend $900 on rotors and pads because of brake shimmers... that dealership service manager should be SHOT!
Aug 12, 2004, 10:39 AM
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I have steering wheel shake as well, but it seems to have gotten worse since the last 5,000 miles. The car currently has 17,000 miles. Is this normal early, and if so, what would you guys do, resurface or get replacement aftermarkets? I don't slam the brakes at all, but who knows what the previous owner did....
