Brake pads
05-25-2013, 02:43 PM
#12
It's a strong claim to say that, "Failure to resurface the rotors will cause vibrations and glazing on the rotor." That claim is more assertive than the older warning labels on tobacco products.
By the way, I've never resurfaced a rotor and have never had vibration or glazing issues. But don't take my word for it. I don't get paid to cut rotors.
By the way, I've never resurfaced a rotor and have never had vibration or glazing issues. But don't take my word for it. I don't get paid to cut rotors.
05-25-2013, 06:17 PM
#13
Maybe for everyone who uses their S as a weekend warrior "pad slapping" is enough for you but to do it PROPERLY for a car driven daily, resurfaced rotors are essential. Work in a shop and watch other techs have come backs for vibrations, its real. Not every car is built the same. Lets just say the OE Honda rotors are made pretty damn well to withstand cycles of new pads on a glazed friction coefficient. Its science. Ra stands for the friction coefficient (roughness average) regarding rotor surface. The rotor should have a new, non directional surface with an Ra of between 40-50. If you paid the bill to own an S why not spend 40$ to drop your rotors off and have them resurfaced? Im sure someone else will have another comment about their shade tree skills. Lets hear the next argument.
http://www.counterman.com/article/91...o_replace.aspx
http://www.tomorrowstechnician.com/A...r_replace.aspx
http://www.counterman.com/article/91...o_replace.aspx
http://www.tomorrowstechnician.com/A...r_replace.aspx
05-26-2013, 03:47 AM
#14
Registered User
I'm not going to get my rotors turned because it's too expensive and provides no benefits.
The amount of money and time spent to get them turned is way too high. I don't have vibration problems. Why should I spend so much to fix something that isn't a problem?
The front pads cost about $42 ($55 shipped). On top of that I use a minuscule of grease and other consumables. a You want to add another $40 to that and you don't realize that's a significant increase. That's almost double the cost.
Let's look at the amount of time needed. Since I value my time, I tend to order stuff online. It doesn't take that long for me to swap the front pads. I only need to have one wheel off at a time. If I were to pull the rotors, I'd have to pull both. I need a second jack stand. I don't have a garage so I'd put away the tools, tidy up, and wash up in the middle of the job. I have no idea how much extra work there is, but this adds up.
Then there's the time to get the rotors turned. I need to drive over to a shop, drop them off, go home, go back and pick them up, and then finish the job. Even if the shop is only 12 minutes away, and I only spend 6 minutes inside each time, that adds an hour. This pretty much doubles the amount of time spent and spreads it to two sessions.
So to summarize. Double the cost in $. Double the cost in time. Zero added benefit.
Now, if I did have a vibration problem... I'd just get new rotors. There's a good chance that the vibration problem is hardness related and as the links you provided point out, turning the rotor won't help.
Even if it was free, I wouldn't turn non-vibrating rotors as a preventative step. If I have no vibration problems, there's a chance that something might not be true on the car, rotor, or brake lathe. By using a non-on-car lathe, there's a chance I can induce runout. If it runs true now, why change it?
If I turn the rotors, I'm removing metal and making them thinner. This brings them closer to the minimum thickness spec which means my rotors would wear out and need to be replaced sooner. In addition, they'll perform worse thermally. The thinner rotors will have less thermal mass and won't transfer heat as well.
What about Ra? Ra is a measurement of surface roughness. This is a direct measurement of the rotor. It's not the coefficient of friction. The coefficient of friction if a property of the material pair (both the rotor and the pad). Both of your articles, which are both by Larry Carley, shouldn't be taken too seriously. They spec out the surface roughness in inches instead of microinches (only off by a factor of 1 million). I've never seen an instrument capable of measuring surface roughness in the range of 10s of inches. Even if the rotors are a little grooved, they still flat in the tangential direction which is the direction in which the rotor is acting on the pad. Surface finish and grooving is mostly a cosmetic issue. Not performance. Furthermore, I've yet to see someone unable to engage the ABS/lock the wheels on their daily driver. If you can do this, then you have more than enough friction between the rotor and the brake pad.
About resurfacing every time, even this poor article mentions states:
Resurfacing a rotor obviously removes metal, making the rotor thinner and reducing its remaining service life. Because of this, some consumers as well as some vehicle manufacturers say rotors should not be resurfaced every time the pads are replaced (unless the rotors are badly grooved or uneven).
The amount of money and time spent to get them turned is way too high. I don't have vibration problems. Why should I spend so much to fix something that isn't a problem?
The front pads cost about $42 ($55 shipped). On top of that I use a minuscule of grease and other consumables. a You want to add another $40 to that and you don't realize that's a significant increase. That's almost double the cost.
Let's look at the amount of time needed. Since I value my time, I tend to order stuff online. It doesn't take that long for me to swap the front pads. I only need to have one wheel off at a time. If I were to pull the rotors, I'd have to pull both. I need a second jack stand. I don't have a garage so I'd put away the tools, tidy up, and wash up in the middle of the job. I have no idea how much extra work there is, but this adds up.
Then there's the time to get the rotors turned. I need to drive over to a shop, drop them off, go home, go back and pick them up, and then finish the job. Even if the shop is only 12 minutes away, and I only spend 6 minutes inside each time, that adds an hour. This pretty much doubles the amount of time spent and spreads it to two sessions.
So to summarize. Double the cost in $. Double the cost in time. Zero added benefit.
Now, if I did have a vibration problem... I'd just get new rotors. There's a good chance that the vibration problem is hardness related and as the links you provided point out, turning the rotor won't help.
Even if it was free, I wouldn't turn non-vibrating rotors as a preventative step. If I have no vibration problems, there's a chance that something might not be true on the car, rotor, or brake lathe. By using a non-on-car lathe, there's a chance I can induce runout. If it runs true now, why change it?
If I turn the rotors, I'm removing metal and making them thinner. This brings them closer to the minimum thickness spec which means my rotors would wear out and need to be replaced sooner. In addition, they'll perform worse thermally. The thinner rotors will have less thermal mass and won't transfer heat as well.
What about Ra? Ra is a measurement of surface roughness. This is a direct measurement of the rotor. It's not the coefficient of friction. The coefficient of friction if a property of the material pair (both the rotor and the pad). Both of your articles, which are both by Larry Carley, shouldn't be taken too seriously. They spec out the surface roughness in inches instead of microinches (only off by a factor of 1 million). I've never seen an instrument capable of measuring surface roughness in the range of 10s of inches. Even if the rotors are a little grooved, they still flat in the tangential direction which is the direction in which the rotor is acting on the pad. Surface finish and grooving is mostly a cosmetic issue. Not performance. Furthermore, I've yet to see someone unable to engage the ABS/lock the wheels on their daily driver. If you can do this, then you have more than enough friction between the rotor and the brake pad.
About resurfacing every time, even this poor article mentions states:
Resurfacing a rotor obviously removes metal, making the rotor thinner and reducing its remaining service life. Because of this, some consumers as well as some vehicle manufacturers say rotors should not be resurfaced every time the pads are replaced (unless the rotors are badly grooved or uneven).
05-26-2013, 04:05 AM
#15
Registered User
Some more writing from Larry Carley:
http://www.brakeandfrontend.com/Arti...need_them.aspx
GM also says that rotors are not to be resurfaced in an attempt to correct the following conditions: noise/squeal, cosmetic corrosion, routine pad replacement, or discoloration/hard spots. GM also says that unnecessary resurfacing only shortens rotor life — unless GM tells you to do so in a technical service bulletin to eliminate a brake noise problem.
...
THE FINAL STEP THAT EVERYBODY FORGETS
If you turn your rotors with sharp bits, and use the proper feed rate and depth of cut, there’s probably no need to apply a nondirectional finish as a final step. The rotors should be ready to install when they come off the lathe — provided you clean them first. That’s the final step that most technicians forget.
Not washing the rotors after they have been turned can leave a lot of junk on the surface that can embed itself in the pads and possibly cause braking as well as noise issues when the rotors are installed. Spraying the rotors with some aerosol brake cleaner and then wiping them off is better than nothing, but it really doesn’t do a very good job of removing surface debris. What you need is warm, soapy water, a good stiff brush and a little elbow grease.
Surely, you wash the rotors every time you cut them, right?
http://www.brakeandfrontend.com/Arti...need_them.aspx
GM also says that rotors are not to be resurfaced in an attempt to correct the following conditions: noise/squeal, cosmetic corrosion, routine pad replacement, or discoloration/hard spots. GM also says that unnecessary resurfacing only shortens rotor life — unless GM tells you to do so in a technical service bulletin to eliminate a brake noise problem.
...
THE FINAL STEP THAT EVERYBODY FORGETS
If you turn your rotors with sharp bits, and use the proper feed rate and depth of cut, there’s probably no need to apply a nondirectional finish as a final step. The rotors should be ready to install when they come off the lathe — provided you clean them first. That’s the final step that most technicians forget.
Not washing the rotors after they have been turned can leave a lot of junk on the surface that can embed itself in the pads and possibly cause braking as well as noise issues when the rotors are installed. Spraying the rotors with some aerosol brake cleaner and then wiping them off is better than nothing, but it really doesn’t do a very good job of removing surface debris. What you need is warm, soapy water, a good stiff brush and a little elbow grease.
Surely, you wash the rotors every time you cut them, right?
05-26-2013, 08:45 AM
#16
Its always an uphill battle debating with jokers that have money and the ambition to always be right vs people who acutally work on cars for a living. You keep on pad slappin your S and anything else that makes ya happy 
. Im glad you could find a link about GM rotors since that relates to Honda so much.
. Im glad you could find a link about GM rotors since that relates to Honda so much.
05-26-2013, 01:09 PM
#17
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Dear BLAQ&GREYs2k,
Would you be so kind to reveal the name of the place where you work?
I think the forum moderators will "look the other way" on this one, about sponsorship issues etc., because I think this is vital info for the viewers of this topic.
It will be a great service and a great help.
Everyone: AVOID the place mentioned by BLAQ&GREYs2k
DO NOT take your car there!
Why?
Because BLAQ&GREYs2k makes at least one vital mistake/error in this changing pads post.
And when it comes to brakes that's the last thing you want... right?
He spends the majority of his first post about resurfacing rotors and how imparitive this is.
While doing so he barely mentioned the brake fluid, and that's way more important.
All he suggests is that there will be no loss of fluid, it will just cycle back & forth.
Why doesn't he ask his clients (or the OP) how old the fluid is?
It's pretty common for the pads to last a while and I think its fair to say that the fluid lasts as long as the pads.
IOW: change pads = change fluid.
Common sense, good practice.
But no, lets keep this who-knows-how-old-fluid in there, change pads and spend $20 a side on resurfacing rotors.
It probalbly to get the customer back in the shop later on to change fluid according to a maintenance schedule.
Good for business!
Good for you, BAD for the customer.
Old brake fluid will be contaminated with water and will corrode parts like pistons.
Rusted pistons will stick and make brakes - especially the rears - run hot, very hot.
That's bad.
And it so easy.
Remove the caliper, attach tube to bleeder, open bleeder and push piston back in to push all that old stuff OUT of the caliper and NOT back into the system, as BLAQ&GREYs2k suggests.
Its not that he forgot to mention this, read his firts post about the fluid.
Now, to get Sk2 specific:
The sliding pins do not come out when you remove the caliper, the hex size bolt is 12mm.
The bracket has hex 14mm bolts to attach it to the knuckle.
The rear pistons have to be turned back in.
The rear pads have a pin that needs to line up with a cross groove in the piston.
And....
To suggest to tighten every bolt .. VERY TIGHT ... is not that good.
I agree its not easy to use a 1/4" torque wrench on the 12mm bolts as there is not much room there.
Maybe a smaller size wrench does fit?
To just call it VERY TIGHT is like: wait for it.... wait for it... gone.
What's very tight for one is just hand tight for another.
That's why they spec torque.
Now.... lest see how BLAQ&GREYs2k reacts.
Is he able to come up with reasonable comments about the issues I mentioned?
(Is he able to admit mistakes and learn?)
Uphill battle huh...?
Have fun!
Would you be so kind to reveal the name of the place where you work?
I think the forum moderators will "look the other way" on this one, about sponsorship issues etc., because I think this is vital info for the viewers of this topic.
It will be a great service and a great help.
Everyone: AVOID the place mentioned by BLAQ&GREYs2k
DO NOT take your car there!
Why?
Because BLAQ&GREYs2k makes at least one vital mistake/error in this changing pads post.
And when it comes to brakes that's the last thing you want... right?
He spends the majority of his first post about resurfacing rotors and how imparitive this is.
While doing so he barely mentioned the brake fluid, and that's way more important.
All he suggests is that there will be no loss of fluid, it will just cycle back & forth.
Why doesn't he ask his clients (or the OP) how old the fluid is?
It's pretty common for the pads to last a while and I think its fair to say that the fluid lasts as long as the pads.
IOW: change pads = change fluid.
Common sense, good practice.
But no, lets keep this who-knows-how-old-fluid in there, change pads and spend $20 a side on resurfacing rotors.
It probalbly to get the customer back in the shop later on to change fluid according to a maintenance schedule.
Good for business!
Good for you, BAD for the customer.
Old brake fluid will be contaminated with water and will corrode parts like pistons.
Rusted pistons will stick and make brakes - especially the rears - run hot, very hot.
That's bad.
And it so easy.
Remove the caliper, attach tube to bleeder, open bleeder and push piston back in to push all that old stuff OUT of the caliper and NOT back into the system, as BLAQ&GREYs2k suggests.
Its not that he forgot to mention this, read his firts post about the fluid.
Now, to get Sk2 specific:
The sliding pins do not come out when you remove the caliper, the hex size bolt is 12mm.
The bracket has hex 14mm bolts to attach it to the knuckle.
The rear pistons have to be turned back in.
The rear pads have a pin that needs to line up with a cross groove in the piston.
And....
To suggest to tighten every bolt .. VERY TIGHT ... is not that good.
I agree its not easy to use a 1/4" torque wrench on the 12mm bolts as there is not much room there.
Maybe a smaller size wrench does fit?
To just call it VERY TIGHT is like: wait for it.... wait for it... gone.
What's very tight for one is just hand tight for another.
That's why they spec torque.
Now.... lest see how BLAQ&GREYs2k reacts.
Is he able to come up with reasonable comments about the issues I mentioned?
(Is he able to admit mistakes and learn?)
Uphill battle huh...?
Have fun!
05-26-2013, 03:37 PM
#18
Both sides have valid arguments. Yes, textbook method states to resurface rotors each and every time you change pads. However, if your rotors are straight and has a clean surface (many ways to do this), drop in the pads and you're good to go.
For a shop who works on customers' cars with unknown pedigree; your safest bet is to clean up their rotor for a happy customer.
As for the reference to GM for Honda cars, that's perfectly valid. Hydraulic brakes are nothing special, GM, Honda, pick your brand, common points apply.
For a shop who works on customers' cars with unknown pedigree; your safest bet is to clean up their rotor for a happy customer.
As for the reference to GM for Honda cars, that's perfectly valid. Hydraulic brakes are nothing special, GM, Honda, pick your brand, common points apply.
05-26-2013, 06:02 PM
#19
Join Date: Aug 2012
Location: Foothills East of Sacramento
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1,045 Posts
Tempest in a teapot. I agree both sides have valid points but the point of views are always going to be different. Changing the brake fluid? Makes sense but I just did that < 1 year and 5 thousand miles ago without a brake pad/rotor job. I just wanted it done on my schedule. In that case I would not have a problem having the calipers push the "old fluid" back to the system. Its nice golden fluid. Someone else may have a different story and a fluid swap would be an important item.
Torque? Yep. In the aviation business that is a super critical component of maintenance that can have life and death consequences. No need to preach to me about proper torque. Can't pull over on the shoulder in the sky. However, for something like autos especially when you do this day in and out, I would think you would get pretty darn good at estimating torque, hence the comment about "tight".
Being in a service industry myself (airline) I can sympathize that so many customers would be coming back bitching about sound and vibration. You want the customer (who also values time and $) to be happy for the price he is going to pay at the dealer/shop. The rub is that is balanced by the desire for profits of said shop. However dealer high prices drives me to do as much of the work on my cars myself. Why not? I also happen to enjoy doing it as long as its within the limits of the tools that I have. I have not looked too deep in the literature on turning rotors every time you do a pad change; I am inclined to let them be if they seem to be fine, have done that in the past and will do so in the future. (Have not had the chance yet with my S) When I do have them turned I have them done on the car to ensure they are true to the vehicle. I am fortunate to have a long time friend who runs a pretty big full service shop who can do that and does not rip me off on exorbitant prices.
That being said, I have only had my S for a little over a year now and and pay attention to these forums; this is a special car and I want to keep it in tip top shape. I cannot imagine ever selling this car.
So... it brings me to my question that I had in my mind when I started to read this thread: Why not just replace the rotors when you get to the point of resurfacing them? If you need to resurface why not just get new ones? No cleaning, no downtown at the shop, nice thick straight rotors.
Comments?
Torque? Yep. In the aviation business that is a super critical component of maintenance that can have life and death consequences. No need to preach to me about proper torque. Can't pull over on the shoulder in the sky. However, for something like autos especially when you do this day in and out, I would think you would get pretty darn good at estimating torque, hence the comment about "tight".
Being in a service industry myself (airline) I can sympathize that so many customers would be coming back bitching about sound and vibration. You want the customer (who also values time and $) to be happy for the price he is going to pay at the dealer/shop. The rub is that is balanced by the desire for profits of said shop. However dealer high prices drives me to do as much of the work on my cars myself. Why not? I also happen to enjoy doing it as long as its within the limits of the tools that I have. I have not looked too deep in the literature on turning rotors every time you do a pad change; I am inclined to let them be if they seem to be fine, have done that in the past and will do so in the future. (Have not had the chance yet with my S) When I do have them turned I have them done on the car to ensure they are true to the vehicle. I am fortunate to have a long time friend who runs a pretty big full service shop who can do that and does not rip me off on exorbitant prices.
That being said, I have only had my S for a little over a year now and and pay attention to these forums; this is a special car and I want to keep it in tip top shape. I cannot imagine ever selling this car.
So... it brings me to my question that I had in my mind when I started to read this thread: Why not just replace the rotors when you get to the point of resurfacing them? If you need to resurface why not just get new ones? No cleaning, no downtown at the shop, nice thick straight rotors.
Comments?
05-26-2013, 08:35 PM
#20
Registered User
Tempest in a teapot. I agree both sides have valid points but the point of views are always going to be different. Changing the brake fluid? Makes sense but I just did that < 1 year and 5 thousand miles ago without a brake pad/rotor job. I just wanted it done on my schedule. In that case I would not have a problem having the calipers push the "old fluid" back to the system. Its nice golden fluid. Someone else may have a different story and a fluid swap would be an important item.
Torque? Yep. In the aviation business that is a super critical component of maintenance that can have life and death consequences. No need to preach to me about proper torque. Can't pull over on the shoulder in the sky. However, for something like autos especially when you do this day in and out, I would think you would get pretty darn good at estimating torque, hence the comment about "tight".
Being in a service industry myself (airline) I can sympathize that so many customers would be coming back bitching about sound and vibration. You want the customer (who also values time and $) to be happy for the price he is going to pay at the dealer/shop. The rub is that is balanced by the desire for profits of said shop. However dealer high prices drives me to do as much of the work on my cars myself. Why not? I also happen to enjoy doing it as long as its within the limits of the tools that I have. I have not looked too deep in the literature on turning rotors every time you do a pad change; I am inclined to let them be if they seem to be fine, have done that in the past and will do so in the future. (Have not had the chance yet with my S) When I do have them turned I have them done on the car to ensure they are true to the vehicle. I am fortunate to have a long time friend who runs a pretty big full service shop who can do that and does not rip me off on exorbitant prices.
That being said, I have only had my S for a little over a year now and and pay attention to these forums; this is a special car and I want to keep it in tip top shape. I cannot imagine ever selling this car.
So... it brings me to my question that I had in my mind when I started to read this thread: Why not just replace the rotors when you get to the point of resurfacing them? If you need to resurface why not just get new ones? No cleaning, no downtown at the shop, nice thick straight rotors.
Comments?
Torque? Yep. In the aviation business that is a super critical component of maintenance that can have life and death consequences. No need to preach to me about proper torque. Can't pull over on the shoulder in the sky. However, for something like autos especially when you do this day in and out, I would think you would get pretty darn good at estimating torque, hence the comment about "tight".
Being in a service industry myself (airline) I can sympathize that so many customers would be coming back bitching about sound and vibration. You want the customer (who also values time and $) to be happy for the price he is going to pay at the dealer/shop. The rub is that is balanced by the desire for profits of said shop. However dealer high prices drives me to do as much of the work on my cars myself. Why not? I also happen to enjoy doing it as long as its within the limits of the tools that I have. I have not looked too deep in the literature on turning rotors every time you do a pad change; I am inclined to let them be if they seem to be fine, have done that in the past and will do so in the future. (Have not had the chance yet with my S) When I do have them turned I have them done on the car to ensure they are true to the vehicle. I am fortunate to have a long time friend who runs a pretty big full service shop who can do that and does not rip me off on exorbitant prices.
That being said, I have only had my S for a little over a year now and and pay attention to these forums; this is a special car and I want to keep it in tip top shape. I cannot imagine ever selling this car.
So... it brings me to my question that I had in my mind when I started to read this thread: Why not just replace the rotors when you get to the point of resurfacing them? If you need to resurface why not just get new ones? No cleaning, no downtown at the shop, nice thick straight rotors.
Comments?
I completely agree about just replacing the rotors. I said exactly that already.
Now, if I did have a vibration problem... I'd just get new rotors. There's a good chance that the vibration problem is hardness related and as the links you provided point out, turning the rotor won't help.