I agree that pads are often what create an uneven rotor surface. What I see a lot of here in northern NY is pads that stick in the slides and heat up the rotors. Rust burs develop that don't allow the pads to release. When people just replace pads and don't properly service the hangers, the same thing reoccurs in a very short period of time, even with new rotors.
Is there no way to avoid warping rotors?
- Thread starter Carnoobie
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Originally Posted By: spasm3
I always use a torque wrench to tight the wheel lugs, on new rotors before they see any heat. When i have tires installed ,I loosen and torque them in the parking lot before i leave ( put any heat in them) . Heat seems to set a warp , and if some meathead got the lugs too tight, i have not left the tire place yet. Works for me.
Yeah but dont you need to jack up the vehicle and take the weight off the wheels to properly re torque them?
I always use a torque wrench to tight the wheel lugs, on new rotors before they see any heat. When i have tires installed ,I loosen and torque them in the parking lot before i leave ( put any heat in them) . Heat seems to set a warp , and if some meathead got the lugs too tight, i have not left the tire place yet. Works for me.
Yeah but dont you need to jack up the vehicle and take the weight off the wheels to properly re torque them?
Originally Posted By: dparm
Also, what pads are you using?
Wagner thermal quiets (ceramic) with Napa Premium rotors (top grade ones). I dont cheap out on brakes. Ive known quite a few with Wagners.
Originally Posted By: yonyon
First, you need to get them true once for a good starting point. New rotors shoved on there are going to have some lateral runout and may also have some conicity. Conicity isn't much of an issue, but lateral runout is. Shims can help a lot with lateral runout. An on-car lathe can machine them true as-mounted for effectively zero runout.
With a good starting point you would then need to keep them trued up. I like to creep at stops, but your parking brake trick should be just as good. Don't forget to use engine braking as appropriate on downgrades.
You're still unemployed right now, yes? If the car sits for days at a time you also have corrosion to deal with. The obvious answer would be to drive the car around the block once a day, but as a Bitoger I think maybe you would also see the downside to this extreme short tripping. As an alternative, do it once every three days as a minimum and within 24 hours after any rain or fog event. This also means you'll need to at least consider making at least one longer trip per week.
Yes but i drive my car daily to at least go get food and though not far, I let the car get hot before shutting it off. I still have normal driving with longer distances 3-4x every week. This week and next week im working a temp job so ill be doing longer trips.
Originally Posted By: Artem
It's the pads that are ruining your rotors. I have Hawk HPS pads on plain blank rotors and run my Scion tC VERY HARD, always on the brakes at the last second, ABS blinking, tires squealing. It's been a good 2 years and everything is perfect. Still smooth as glass even braking from 100mph+.
I say you upgrade your pads to something that can handle a bit more heat. AZ has performance oriented pads available.
Even though ceramic pads have better performance and last longer and no brake dust i was told theyre much harder on the rotors as they dig in deeper than semi ceramic pads. I wonder if this could be it, that my pads being full ceramic are too rough for the rotors.
Also, what pads are you using?
Wagner thermal quiets (ceramic) with Napa Premium rotors (top grade ones). I dont cheap out on brakes. Ive known quite a few with Wagners.
Originally Posted By: yonyon
First, you need to get them true once for a good starting point. New rotors shoved on there are going to have some lateral runout and may also have some conicity. Conicity isn't much of an issue, but lateral runout is. Shims can help a lot with lateral runout. An on-car lathe can machine them true as-mounted for effectively zero runout.
With a good starting point you would then need to keep them trued up. I like to creep at stops, but your parking brake trick should be just as good. Don't forget to use engine braking as appropriate on downgrades.
You're still unemployed right now, yes? If the car sits for days at a time you also have corrosion to deal with. The obvious answer would be to drive the car around the block once a day, but as a Bitoger I think maybe you would also see the downside to this extreme short tripping. As an alternative, do it once every three days as a minimum and within 24 hours after any rain or fog event. This also means you'll need to at least consider making at least one longer trip per week.
Yes but i drive my car daily to at least go get food and though not far, I let the car get hot before shutting it off. I still have normal driving with longer distances 3-4x every week. This week and next week im working a temp job so ill be doing longer trips.
Originally Posted By: Artem
It's the pads that are ruining your rotors. I have Hawk HPS pads on plain blank rotors and run my Scion tC VERY HARD, always on the brakes at the last second, ABS blinking, tires squealing. It's been a good 2 years and everything is perfect. Still smooth as glass even braking from 100mph+.
I say you upgrade your pads to something that can handle a bit more heat. AZ has performance oriented pads available.
Even though ceramic pads have better performance and last longer and no brake dust i was told theyre much harder on the rotors as they dig in deeper than semi ceramic pads. I wonder if this could be it, that my pads being full ceramic are too rough for the rotors.
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Originally Posted By: blacklamb
I also sufferED from "warped" rotors back in the day, solid face or slotted I always had a "warped rotor" feeling. I then started to poke around the ol internet and didn’t really find an answer until I saw the how to bed in brakes. I happened to have some Porterfield R4 pad a bit overkill for my Mini more than likely but my god it stops on a micron. So I installed my pads and rotors (EBC Ultimax) and ATE Superblue fluid and toqued my wheels and headed off for the bed in process. After doing the full bed in process (smoking brakes and all) I drove around for a while then headed home. From that point on I've NEVER had a shudder in my brakes and I've put my pad and rotor combo to the test I've had them smoking so many times I can’t even count anymore and they still are smooth as silk. I am now a firm believer in the bed in process.
I bedded my pads in when new but just curious what was your process exactly?
BTw this is for civic, torque spec for lugs is 80ft lbs but can do with 90 too. From talking with a lot of mechs most say 80 is bit light and go 90 and wont make different in a bad way.
My pads on now theyre only a year old maybe a bit longer, about 14 or 15k km on them. Same with the rotors, I probably have about 70% at least left if not more. Im wondering if I should just use them til they need replacement before putting new ones on for the sake of not wasting money or replacing parts still good.
But what are the long term effects of driving on warped rotors? I dont know how warped mine are (or even if they are forsure) but im pretty sure they are if im getting a slight pulsating feeling when i brake. Cause you shouldnt be feeling anything at all when you brake right? Not even the slighest bit of pulsation?
Ive had one of my mechanics before tell me not to worry about it cause when i brake hard i dont get any vibrating in my steering wheel or anything.
I also sufferED from "warped" rotors back in the day, solid face or slotted I always had a "warped rotor" feeling. I then started to poke around the ol internet and didn’t really find an answer until I saw the how to bed in brakes. I happened to have some Porterfield R4 pad a bit overkill for my Mini more than likely but my god it stops on a micron. So I installed my pads and rotors (EBC Ultimax) and ATE Superblue fluid and toqued my wheels and headed off for the bed in process. After doing the full bed in process (smoking brakes and all) I drove around for a while then headed home. From that point on I've NEVER had a shudder in my brakes and I've put my pad and rotor combo to the test I've had them smoking so many times I can’t even count anymore and they still are smooth as silk. I am now a firm believer in the bed in process.
I bedded my pads in when new but just curious what was your process exactly?
BTw this is for civic, torque spec for lugs is 80ft lbs but can do with 90 too. From talking with a lot of mechs most say 80 is bit light and go 90 and wont make different in a bad way.
My pads on now theyre only a year old maybe a bit longer, about 14 or 15k km on them. Same with the rotors, I probably have about 70% at least left if not more. Im wondering if I should just use them til they need replacement before putting new ones on for the sake of not wasting money or replacing parts still good.
But what are the long term effects of driving on warped rotors? I dont know how warped mine are (or even if they are forsure) but im pretty sure they are if im getting a slight pulsating feeling when i brake. Cause you shouldnt be feeling anything at all when you brake right? Not even the slighest bit of pulsation?
Ive had one of my mechanics before tell me not to worry about it cause when i brake hard i dont get any vibrating in my steering wheel or anything.
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Ceramic pads are not harder on rotors than semi-metallics. They are easier on rotors. Although metallics being more abrasive seem to wear rotors more evenly in thickness and are a little less likely to develop pulsation even if they do tend to be noisier and more brake dust. This might be part of the reason why when some people switch to a high performance metallic pad they no longer develop pulsation.
As I already explained, your rotors are most likely not warped (no longer flat), but worn uneven. It's the classic scenario, you put on relatively quality new pads and rotors, the caliper pins slide fine and so do the pads on their quide clips. But 5-8k miles later or so you develop pulsation. Most likely the rotor run out was excessive, for whatever reason (hub and rotor stacked run out tolerance, overtightening lug nuts, corrosion), and wore the rotors unevenly. The fix is to turn the rotors on-car and make sure the run out is within tolerance.
As I already explained, your rotors are most likely not warped (no longer flat), but worn uneven. It's the classic scenario, you put on relatively quality new pads and rotors, the caliper pins slide fine and so do the pads on their quide clips. But 5-8k miles later or so you develop pulsation. Most likely the rotor run out was excessive, for whatever reason (hub and rotor stacked run out tolerance, overtightening lug nuts, corrosion), and wore the rotors unevenly. The fix is to turn the rotors on-car and make sure the run out is within tolerance.
Originally Posted By: dparm
Rotors don't warp, they get pad transfer which leads to an uneven surface.
To fix this, re-bed them:
http://www.zeckhausen.com/bedding_in_brakes.htm
My pal, Dave Z! What a great guy. Fountain of knowledge and a Stoptech dealer and developer as well.
Many people mistake a pad problem for a rotor problem. Be sure and read these papers thoroughly as there are detailed instructions.
I have cured a lot of brake issues with a simple bedding that used to mean disassembly and new parts.
Rotors don't warp, they get pad transfer which leads to an uneven surface.
To fix this, re-bed them:
http://www.zeckhausen.com/bedding_in_brakes.htm
My pal, Dave Z! What a great guy. Fountain of knowledge and a Stoptech dealer and developer as well.
Many people mistake a pad problem for a rotor problem. Be sure and read these papers thoroughly as there are detailed instructions.
I have cured a lot of brake issues with a simple bedding that used to mean disassembly and new parts.
Originally Posted By: Carnoobie
Originally Posted By: blacklamb
I also sufferED from "warped" rotors back in the day, solid face or slotted I always had a "warped rotor" feeling. I then started to poke around the ol internet and didn’t really find an answer until I saw the how to bed in brakes. I happened to have some Porterfield R4 pad a bit overkill for my Mini more than likely but my god it stops on a micron. So I installed my pads and rotors (EBC Ultimax) and ATE Superblue fluid and toqued my wheels and headed off for the bed in process. After doing the full bed in process (smoking brakes and all) I drove around for a while then headed home. From that point on I've NEVER had a shudder in my brakes and I've put my pad and rotor combo to the test I've had them smoking so many times I can’t even count anymore and they still are smooth as silk. I am now a firm believer in the bed in process.
I bedded my pads in when new but just curious what was your process exactly?
BTw this is for civic, torque spec for lugs is 80ft lbs but can do with 90 too. From talking with a lot of mechs most say 80 is bit light and go 90 and wont make different in a bad way.
My pads on now theyre only a year old maybe a bit longer, about 14 or 15k km on them. Same with the rotors, I probably have about 70% at least left if not more. Im wondering if I should just use them til they need replacement before putting new ones on for the sake of not wasting money or replacing parts still good.
But what are the long term effects of driving on warped rotors? I dont know how warped mine are (or even if they are forsure) but im pretty sure they are if im getting a slight pulsating feeling when i brake. Cause you shouldnt be feeling anything at all when you brake right? Not even the slighest bit of pulsation?
Ive had one of my mechanics before tell me not to worry about it cause when i brake hard i dont get any vibrating in my steering wheel or anything.
http://www.stableenergies.com/porterfield_brake_pad_bedding.htm
Originally Posted By: blacklamb
I also sufferED from "warped" rotors back in the day, solid face or slotted I always had a "warped rotor" feeling. I then started to poke around the ol internet and didn’t really find an answer until I saw the how to bed in brakes. I happened to have some Porterfield R4 pad a bit overkill for my Mini more than likely but my god it stops on a micron. So I installed my pads and rotors (EBC Ultimax) and ATE Superblue fluid and toqued my wheels and headed off for the bed in process. After doing the full bed in process (smoking brakes and all) I drove around for a while then headed home. From that point on I've NEVER had a shudder in my brakes and I've put my pad and rotor combo to the test I've had them smoking so many times I can’t even count anymore and they still are smooth as silk. I am now a firm believer in the bed in process.
I bedded my pads in when new but just curious what was your process exactly?
BTw this is for civic, torque spec for lugs is 80ft lbs but can do with 90 too. From talking with a lot of mechs most say 80 is bit light and go 90 and wont make different in a bad way.
My pads on now theyre only a year old maybe a bit longer, about 14 or 15k km on them. Same with the rotors, I probably have about 70% at least left if not more. Im wondering if I should just use them til they need replacement before putting new ones on for the sake of not wasting money or replacing parts still good.
But what are the long term effects of driving on warped rotors? I dont know how warped mine are (or even if they are forsure) but im pretty sure they are if im getting a slight pulsating feeling when i brake. Cause you shouldnt be feeling anything at all when you brake right? Not even the slighest bit of pulsation?
Ive had one of my mechanics before tell me not to worry about it cause when i brake hard i dont get any vibrating in my steering wheel or anything.
http://www.stableenergies.com/porterfield_brake_pad_bedding.htm
Originally Posted By: SteveSRT8
Originally Posted By: dparm
Rotors don't warp, they get pad transfer which leads to an uneven surface.
To fix this, re-bed them:
http://www.zeckhausen.com/bedding_in_brakes.htm
My pal, Dave Z! What a great guy. Fountain of knowledge and a Stoptech dealer and developer as well.
Many people mistake a pad problem for a rotor problem. Be sure and read these papers thoroughly as there are detailed instructions.
I have cured a lot of brake issues with a simple bedding that used to mean disassembly and new parts.
+2. I use cheap no name brakes on my cars, never have a problem. have some Canadian no-name pads and drilled rotors on my Mazda5 I bought on ebay, no issues, no so-called 'warping', excellent performance. I put some cheap ebay brakes on the front of my camry also, no issues.
OTOH, my carpool buddy had a shop do his front brakes this past year, and he now has a severe shuddering problem, the car is almost undrivable.
I fully support the need to bed in brakes properly, along with a careful install of the anti-squeal spray on the back of the pads, and cleaning and lubing the sliders.
Originally Posted By: dparm
Rotors don't warp, they get pad transfer which leads to an uneven surface.
To fix this, re-bed them:
http://www.zeckhausen.com/bedding_in_brakes.htm
My pal, Dave Z! What a great guy. Fountain of knowledge and a Stoptech dealer and developer as well.
Many people mistake a pad problem for a rotor problem. Be sure and read these papers thoroughly as there are detailed instructions.
I have cured a lot of brake issues with a simple bedding that used to mean disassembly and new parts.
+2. I use cheap no name brakes on my cars, never have a problem. have some Canadian no-name pads and drilled rotors on my Mazda5 I bought on ebay, no issues, no so-called 'warping', excellent performance. I put some cheap ebay brakes on the front of my camry also, no issues.
OTOH, my carpool buddy had a shop do his front brakes this past year, and he now has a severe shuddering problem, the car is almost undrivable.
I fully support the need to bed in brakes properly, along with a careful install of the anti-squeal spray on the back of the pads, and cleaning and lubing the sliders.
If the uneven, yet often invisible pad deposits fixed by reburnish the pads theory was it, then the pulsation would come and go just from using the brakes. And the brakes wouldn't work fine for several thousands miles and well after the initial burnishing happened only to develop pulsation like clockwork a few thousand miles into service. Most of the pulsation I see is not fixed by reburnishing with several hard stops and is sometimes only made worse.
What I explained earlier is in the OEMs' TSBs and service info and training. OEMs have to warranty brakes and labor for longer than the aftermarket's basically non-existent-blame everything else parts only warranty. And with all the OEMs research and resources I think they know what the issue is and how to fix it. If a few hard stops would do it, wouldn't they'd be all over it recommending that? And it's not only OEMs that reference lateral run out and thickness variation but also some of the major aftermarket brake manufacturers.
I don't mean to start a debate but I just don't get why it seems like all that is often dismissed for the uneven pad deposit from improper pad burnish concept. Besides, the recommended burnish procedure on new street pad and rotors is usually just a dozen moderate stops from about 45 mph to 15 with a 1/4 mile cooled down inbetween, not to get the brakes roasting hot.
But I do understand that using dial indicators to measure run out, on-car brake lathes or correction shims are complications that many would like to avoid. But that often can be the only fix for a hub/rotor assembly with excessive run out.
What I explained earlier is in the OEMs' TSBs and service info and training. OEMs have to warranty brakes and labor for longer than the aftermarket's basically non-existent-blame everything else parts only warranty. And with all the OEMs research and resources I think they know what the issue is and how to fix it. If a few hard stops would do it, wouldn't they'd be all over it recommending that? And it's not only OEMs that reference lateral run out and thickness variation but also some of the major aftermarket brake manufacturers.
I don't mean to start a debate but I just don't get why it seems like all that is often dismissed for the uneven pad deposit from improper pad burnish concept. Besides, the recommended burnish procedure on new street pad and rotors is usually just a dozen moderate stops from about 45 mph to 15 with a 1/4 mile cooled down inbetween, not to get the brakes roasting hot.
But I do understand that using dial indicators to measure run out, on-car brake lathes or correction shims are complications that many would like to avoid. But that often can be the only fix for a hub/rotor assembly with excessive run out.
I think the biggest cause of warped rotors is the amount of chromium and nickle in the alloy. GM now uses some very low chromium and nickle alloy rotors to prevent warping, but without those elements, the rotors rust faster. GM made the decision that rusted rotors were better than warped rotors because most people won't see nor care about rusted rotors, but they can feel warped rotors every time the apply the brakes. Rusted rotors create less warranty repairs than warped rotors.
Originally Posted By: mechanicx
Ceramic pads are not harder on rotors than semi-metallics. They are easier on rotors. Although metallics being more abrasive seem to wear rotors more evenly in thickness and are a little less likely to develop pulsation even if they do tend to be noisier and more brake dust. This might be part of the reason why when some people switch to a high performance metallic pad they no longer develop pulsation.
As I already explained, your rotors are most likely not warped (no longer flat), but worn uneven. It's the classic scenario, you put on relatively quality new pads and rotors, the caliper pins slide fine and so do the pads on their quide clips. But 5-8k miles later or so you develop pulsation. Most likely the rotor run out was excessive, for whatever reason (hub and rotor stacked run out tolerance, overtightening lug nuts, corrosion), and wore the rotors unevenly. The fix is to turn the rotors on-car and make sure the run out is within tolerance.
Full ceramic pads are easier on the rotors than semis? Really?
Cause I had a mech like a year ago say ceramics are rough and not to use them. I thought that didnt sound right. Didnt make sense.
He said one of my rotors (which were about 2 months old at the time) were warped and it wasnt running true. And what caused it was my front wheel hub was bent and cause the rotor to warp. A bent wheel hub can cause a rotor to warp? So he machined the rotor. He said dont replace the hub cause its expensive and instead just machine the rotor first everytime i replace it on the driver side (where the bent hub is).
Since I was concerned about the bent hub, i went and got a second opinion from another mech who did a run out test. It was perfect. Also did the heavy stop from a high speed run and no shimmy or shaking in the steering wheel. And no give at all when trying to rock the wheel with wheel off the ground.
Pulsing came back but took awhile and its not like serious shimmy feel, pretty light. Usually when people get shimmy feel in their brakes they mostly feel it the most when braking hard like from a 80kmh run. I dont feel much if anything at all if I do that. So thats what makes me think i should just leave it for now and use them til they need to be replaced? But what are the long term consequences of driving on brakes with shimmying?
Ceramic pads are not harder on rotors than semi-metallics. They are easier on rotors. Although metallics being more abrasive seem to wear rotors more evenly in thickness and are a little less likely to develop pulsation even if they do tend to be noisier and more brake dust. This might be part of the reason why when some people switch to a high performance metallic pad they no longer develop pulsation.
As I already explained, your rotors are most likely not warped (no longer flat), but worn uneven. It's the classic scenario, you put on relatively quality new pads and rotors, the caliper pins slide fine and so do the pads on their quide clips. But 5-8k miles later or so you develop pulsation. Most likely the rotor run out was excessive, for whatever reason (hub and rotor stacked run out tolerance, overtightening lug nuts, corrosion), and wore the rotors unevenly. The fix is to turn the rotors on-car and make sure the run out is within tolerance.
Full ceramic pads are easier on the rotors than semis? Really?
Cause I had a mech like a year ago say ceramics are rough and not to use them. I thought that didnt sound right. Didnt make sense.
He said one of my rotors (which were about 2 months old at the time) were warped and it wasnt running true. And what caused it was my front wheel hub was bent and cause the rotor to warp. A bent wheel hub can cause a rotor to warp? So he machined the rotor. He said dont replace the hub cause its expensive and instead just machine the rotor first everytime i replace it on the driver side (where the bent hub is).
Since I was concerned about the bent hub, i went and got a second opinion from another mech who did a run out test. It was perfect. Also did the heavy stop from a high speed run and no shimmy or shaking in the steering wheel. And no give at all when trying to rock the wheel with wheel off the ground.
Pulsing came back but took awhile and its not like serious shimmy feel, pretty light. Usually when people get shimmy feel in their brakes they mostly feel it the most when braking hard like from a 80kmh run. I dont feel much if anything at all if I do that. So thats what makes me think i should just leave it for now and use them til they need to be replaced? But what are the long term consequences of driving on brakes with shimmying?
Weren't you the same guy posting a video freaking out that his transmission sounded funny so it needed a boatload of work because you were convinced it was gonna fall out of your car, and everyone said it was totally fine?
Ever consider that you're making something up again?
Ever consider that you're making something up again?
A bent hub would have run out and induce rotor run out. And yes run out would cause uneven wear on the rotor leading to pulsation. Run out and warpage are two different things really. There's too much 2nd hand info here. One mechanic said the hub has run out and machined the rotor (on the car or off?). Then another said there was no run out (at the rotor I presume). I don't know who to believe if any of them.
The service procedure is spelled out clearly in the Honda service manual to measure run out and if exceeding specified tolerance to machine the rotor with an on-car brake lathe. It doesn't sound like you are having service done by a shop that knows what they're doing and stands behind their work.
The service procedure is spelled out clearly in the Honda service manual to measure run out and if exceeding specified tolerance to machine the rotor with an on-car brake lathe. It doesn't sound like you are having service done by a shop that knows what they're doing and stands behind their work.
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Originally Posted By: tommygunn
Weren't you the same guy posting a video freaking out that his transmission sounded funny so it needed a boatload of work because you were convinced it was gonna fall out of your car, and everyone said it was totally fine?
Ever consider that you're making something up again?
Why am I making something up again? I take everything mechs have to say but sometimes i get a second opinion. I was just shocked when this one mech said my drive side hub was bent thats all and have to machine the rotor for it to run true again.
Weren't you the same guy posting a video freaking out that his transmission sounded funny so it needed a boatload of work because you were convinced it was gonna fall out of your car, and everyone said it was totally fine?
Ever consider that you're making something up again?
Why am I making something up again? I take everything mechs have to say but sometimes i get a second opinion. I was just shocked when this one mech said my drive side hub was bent thats all and have to machine the rotor for it to run true again.
Originally Posted By: mechanicx
A bent hub would have run out and yes run out would cause uneven wear on the rotor. There's too much 2nd hand info here, one mechanic said the hub has run out, machined the rotor (one the car or off?)another said there was no run out. I don;t know who to believe.
The service procedure is spelled out clearly in the Honda service manual to measure run out and if excessive to machine the rotor with an on-car brake lathe. It doesn;t sound like you are having service done by a shop that knows what they're doing and stands behind their work.
WHen i had my brakes replaced last spring it was by a mech who i ditched long ago. Hes a mech who doesnt even torque lug nuts after putting back on, he just uses his impact gun and thats it. Remember my thread from ways back, asking what you think of mechs who dont use a torque wrench? Well he was who I was refering to.
When I had the rotors machined and was told the hub was bent it was at another one of my mechs. I just happened to be there cause he was putting on a new serp. belt for me and test drove it and noticed some shimmying and checked the rotors. Thats when he said not to use ceramic pads and that theyre too hard on the rotors digging into it.
It was then when I got a 2nd opinion from another mech for the runout and he did the wheel shake, 6/12 oclock and whatever else, 3/9 I think, and did the hard braking from high speed to see if there was any shaking in the steering wheel and nothing. He said cause of this no way hub can be bent and he didnt do the runout test.
A bent hub would have run out and yes run out would cause uneven wear on the rotor. There's too much 2nd hand info here, one mechanic said the hub has run out, machined the rotor (one the car or off?)another said there was no run out. I don;t know who to believe.
The service procedure is spelled out clearly in the Honda service manual to measure run out and if excessive to machine the rotor with an on-car brake lathe. It doesn;t sound like you are having service done by a shop that knows what they're doing and stands behind their work.
WHen i had my brakes replaced last spring it was by a mech who i ditched long ago. Hes a mech who doesnt even torque lug nuts after putting back on, he just uses his impact gun and thats it. Remember my thread from ways back, asking what you think of mechs who dont use a torque wrench? Well he was who I was refering to.
When I had the rotors machined and was told the hub was bent it was at another one of my mechs. I just happened to be there cause he was putting on a new serp. belt for me and test drove it and noticed some shimmying and checked the rotors. Thats when he said not to use ceramic pads and that theyre too hard on the rotors digging into it.
It was then when I got a 2nd opinion from another mech for the runout and he did the wheel shake, 6/12 oclock and whatever else, 3/9 I think, and did the hard braking from high speed to see if there was any shaking in the steering wheel and nothing. He said cause of this no way hub can be bent and he didnt do the runout test.
I don't know, if your pulsation came and went then maybe you did have some uneven pad depostis that others talked about. Or maybe one of the mechanics properly retorqued your wheels and that helped resolve the issue. I do believe that ceramics, while not harder on rotors, can leave pad deposits more than metallics. Run out can also encourage uneven pad deposits.
It appears you have 3 different mechanics saying three different things and maybe none of them really know what they're talking about. I'm kind of confused now, do you have persistent brake pulsation now or not?
It appears you have 3 different mechanics saying three different things and maybe none of them really know what they're talking about. I'm kind of confused now, do you have persistent brake pulsation now or not?
Originally Posted By: GMorg
I've warped rotors by hitting deep water with hot rotors. Uneven cooling of hot rotors can cause warp too.
That's what I always assumed caused truely warped rotors. Hot rotors driven into a deep water puddle or maybe pulling into a car wash that sprays the wheels. I think it happens more often to the thinner rear solid disks though. Although I don't remember ever seeing it in any published information.
It makes sense to me. Heat up a sauce pan to about the temperature of hot brakes then run water over it and the pan warps just from the rapid uneven cooling. Although, I never seen a thick cast iron pan warp that way, but on the other hand brake rotors are seeing other stresses a pan isn't. And also rotor metallurgy could be a factor as Loobed mentioned. I've seen brakes get very hot from a dragging caiper, maybe cooking the pads, but the rotor didn't warp. Bottomline is I think it's hard to warp a rotor from just heat alone.
I've warped rotors by hitting deep water with hot rotors. Uneven cooling of hot rotors can cause warp too.
That's what I always assumed caused truely warped rotors. Hot rotors driven into a deep water puddle or maybe pulling into a car wash that sprays the wheels. I think it happens more often to the thinner rear solid disks though. Although I don't remember ever seeing it in any published information.
It makes sense to me. Heat up a sauce pan to about the temperature of hot brakes then run water over it and the pan warps just from the rapid uneven cooling. Although, I never seen a thick cast iron pan warp that way, but on the other hand brake rotors are seeing other stresses a pan isn't. And also rotor metallurgy could be a factor as Loobed mentioned. I've seen brakes get very hot from a dragging caiper, maybe cooking the pads, but the rotor didn't warp. Bottomline is I think it's hard to warp a rotor from just heat alone.
Originally Posted By: lexus114
Originally Posted By: spasm3
I always use a torque wrench to tight the wheel lugs, on new rotors before they see any heat. When i have tires installed ,I loosen and torque them in the parking lot before i leave ( put any heat in them) . Heat seems to set a warp , and if some meathead got the lugs too tight, i have not left the tire place yet. Works for me.
Yeah but dont you need to jack up the vehicle and take the weight off the wheels to properly re torque them?
i never have. i do it one lug at a time in a star pattern.
Originally Posted By: spasm3
I always use a torque wrench to tight the wheel lugs, on new rotors before they see any heat. When i have tires installed ,I loosen and torque them in the parking lot before i leave ( put any heat in them) . Heat seems to set a warp , and if some meathead got the lugs too tight, i have not left the tire place yet. Works for me.
Yeah but dont you need to jack up the vehicle and take the weight off the wheels to properly re torque them?
i never have. i do it one lug at a time in a star pattern.
What can we do? Clean mounting surfaces really clean [hub/rotor].
Some cars will never get a problem. Some will, even with care in assembly and moderate driving.
The pad deposition thing is for race car and very high performance stuff.
Very high temps, pilling on the pads, and consistent conditions like this are when pad deposition comes into play.
In normal street driving with Mon n Pop cars, any material is wiped of faster than it can accumulate.
Some cars will never get a problem. Some will, even with care in assembly and moderate driving.
The pad deposition thing is for race car and very high performance stuff.
Very high temps, pilling on the pads, and consistent conditions like this are when pad deposition comes into play.
In normal street driving with Mon n Pop cars, any material is wiped of faster than it can accumulate.
Originally Posted By: dparm
Rotors don't warp, they get pad transfer which leads to an uneven surface.
To fix this, re-bed them:
http://www.zeckhausen.com/bedding_in_brakes.htm
While I agree actual warping is unlikely, runout is also a problem (in addition to pad transfer). The $69.99 brake special at Mavis, do you think they check for runout. Could they explain it if you asked about runout.
Or is that someone who drove their car away without paying.
Before someone tries a re-bed procedure they ought to know what they are dealing with. Like checking runout. They might even have Teves calipers on their Jeep, in which case you can bed the brakes while you are standing on your head and nothing matters until you put on Akebono calipers.
Rotors don't warp, they get pad transfer which leads to an uneven surface.
To fix this, re-bed them:
http://www.zeckhausen.com/bedding_in_brakes.htm
While I agree actual warping is unlikely, runout is also a problem (in addition to pad transfer). The $69.99 brake special at Mavis, do you think they check for runout. Could they explain it if you asked about runout.
Or is that someone who drove their car away without paying.
Before someone tries a re-bed procedure they ought to know what they are dealing with. Like checking runout. They might even have Teves calipers on their Jeep, in which case you can bed the brakes while you are standing on your head and nothing matters until you put on Akebono calipers.
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