Rotors and brake job question

xaeniac

Golden Member
Feb 4, 2005
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Should one replace rotors when replacing brake pads? This is for a 2005 ford focus. The car is not being driven aggressively, and the pads are still good. I assume the rotors are still good as there is no pulsating in the pedal. Should I replace the rotors as well when changing the brake pads?
 

Bartman39

Elite Member | For Sale/Trade
Jul 4, 2000
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It depends on how worn they are... A good shop and I say that more in a honest way will check how worn down they are and if they can be turned (refinished) and still be good... If not then for sure replace them with the pads... 2 things can happen with rotors that are worn beyond the min spec is they will warp much easier due to the lack of material (thinner means easier to distort or warp)... Also they will not handle the heat as well, mainly because they are kinda like heatsinks they require mass to absorb and remove heat so with to much heat the brakes fade and fail...


Also you should always have the rotors turned when replacing pads... Turning or refinishing the rotors will make the pad contact surface level and square so you get full contact of the pad on the rotor... Also the refinish surface is like crosshatching in a cylinder bore it will also seat the pads properly kinda like a set of new rings in a rebuilt engine...
 
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StageLeft

No Lifer
Sep 29, 2000
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Are you saying both rotors AND pads are good? In this case, don't replace anything :)
 

zerocool84

Lifer
Nov 11, 2004
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It depends on how worn they are... A good shop and I say that more in a honest way will check how worn down they are and if they can be turned (refinished) and still be good... If not then for sure replace them with the pads... 2 things can happen with rotors that are worn beyond the min spec is they will warp much easier due to the lack of material (thinner means easier to distort or warp)... Also they will not handle the heat as well, mainly because they are kinda like heatsinks they require mass to absorb and remove heat so with to much heat the brakes fade and fail...


Also you should always have the rotors turned when replacing pads... Turning or refinishing the rotors will make the pad contact surface level and square so you get full contact of the pad on the rotor... Also the refinish surface is like crosshatching in a cylinder bore it will also seat the pads properly kinda like a set of new rings in a rebuilt engine...

Many new cars, in the owners manual they tell you NOT to turn the rotors at all. It's a recent thing. People always need to check the owners manual BEFORE doing any work on their cars or even asking a question here as the owner's manual will answer 99% of questions asked here.
 

Bartman39

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Jul 4, 2000
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Many new cars, in the owners manual they tell you NOT to turn the rotors at all. It's a recent thing. People always need to check the owners manual BEFORE doing any work on their cars or even asking a question here as the owner's manual will answer 99% of questions asked here.


The simple reason for this is they want you to buy new parts only (from the stealer of course)... If you think the owners manual is what people need to rely on then be prepared...

BTW...? What do you do...? (for a living)
 
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skyking

Lifer
Nov 21, 2001
22,783
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I put one set of pads on, and next time I replace the rotors in most cases.
 

bruceb

Diamond Member
Aug 20, 2004
8,874
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Usually, rotors will be fine for use with 2 sets of brake pads. Should be replaced when you install the 3rd set of pads. Depending on rotor wear and scoring, you may need to turn them when installing the second set of brake pads. Be sure you properly clean and use the correct lubricant on the caliper slide pins. It is essential for correct brake function and long pad life.
 

Vette73

Lifer
Jul 5, 2000
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The simple reason for this is they want you to buy new parts only (from the stealer of course)... If you think the owners manual is what people need to rely on then be prepared...

BTW...? What do you do...? (for a living)


Ahh no. Many cars are coming with thinner rotors that are required to stop cars that are much heavier then older ones. I stopped turning rotors on newwer cars during my last couple years as a tech. Some older ones I would turn but newwer ones warp easly esp if they are turned down even more.
Let alone the cost for new rotors in many cases is not much more then what many charge to turn now.
 

Vette73

Lifer
Jul 5, 2000
21,503
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OP if you are worried or plan on keeping the car a very long time then you can get front rotors from rockauto.com for $36 each (RAYBESTOS Pro). Advance Auto has them for $45 each (plenty of coupons out there to bring that down as cheap as RA.com)

Get some ceramic pads and that should do it.
 

cardiac

Platinum Member
Oct 9, 1999
2,082
14
81
Many new cars, in the owners manual they tell you NOT to turn the rotors at all. It's a recent thing. People always need to check the owners manual BEFORE doing any work on their cars or even asking a question here as the owner's manual will answer 99% of questions asked here.

Some rotors are made from a composite material and cannot be turned. Single use only.
 

Gibson486

Lifer
Aug 9, 2000
18,378
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0
Turning rotors in my area is about $25-$30 each unless you go to Pepboys, where it's a far drive and $15 each. A new cheap rotor can be as cheap as $40 and you do not have to make a trip to get your rotors turned.
 

alkemyst

No Lifer
Feb 13, 2001
83,769
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Ahh no. Many cars are coming with thinner rotors that are required to stop cars that are much heavier then older ones. I stopped turning rotors on newwer cars during my last couple years as a tech. Some older ones I would turn but newwer ones warp easly esp if they are turned down even more.
Let alone the cost for new rotors in many cases is not much more then what many charge to turn now.

qft.
 

kornphlake

Golden Member
Dec 30, 2003
1,567
9
81
I don't even know where to take rotors to be turned anymore, I bought new rotors last time I did a brake job, but I've replaced the pads a couple times before that and didn't touch the rotors. I noticed that the old rotors with new pads seated in and gave full power quicker than the new pads with new rotors. Anecdotal at best, but it's my 2 cents.
 

Bartman39

Elite Member | For Sale/Trade
Jul 4, 2000
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Ahh no. Many cars are coming with thinner rotors that are required to stop cars that are much heavier then older ones. I stopped turning rotors on newwer cars during my last couple years as a tech. Some older ones I would turn but newwer ones warp easly esp if they are turned down even more.
Let alone the cost for new rotors in many cases is not much more then what many charge to turn now.


I just cant agree that cars are getting heavier than older ones...? Different models dont mean same ole same ole...? Most manufacturers are still trying to make them lighter for fuel milage and of course cheaper due to less material...

While I agree most newer cars are coming with rotors that barely make a turn after the first set of pads and its almost cheaper in alot of cases to just buy new... But this is not the case with all cars and I have found the material used in alot of the OEM rotors is alot better than it used to be as well... This was done to match the newer pad material which is much harder and more abrasive to improve stopping performance... Will say trucks for the most part dont follow this rule as they have plenty of meat on them but of course its there for the tow rating more than anything... But back to cars higher performance cars will have more material just because they require it (fast accleration does require fast deccleration)...


But back to really what the OP is asking should you replace them uh no if you can have them turned and they are not beyond the min spec which is cast or stamped into the rotor itself... Also if the cost of turning is over 1/2 of the cost of new then it would be a better choice to buy new... BTW I get ours done for $20 per pair and its just down the street and done on a good machine by someone that knows how... I check them myself so know if they can be turned or not and of course call for new prices...

This almost sounds like its getting into a throw away thread...?


[/QUOTE]Some rotors are made from a composite material and cannot be turned. Single use only[/QUOTE]

Exotic cars only from what I have seen... Would`nt even think of not going with new...
 
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Vette73

Lifer
Jul 5, 2000
21,503
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I just cant agree that cars are getting heavier than older ones...? Different models dont mean same ole same ole...? Most manufacturers are still trying to make them lighter for fuel milage and of course cheaper due to less material...

While I agree most newer cars are coming with rotors that barely make a turn after the first set of pads and its almost cheaper in alot of cases to just buy new... But this is not the case with all cars and I have found the material used in alot of the OEM rotors is alot better than it used to be as well... This was done to match the newer pad material which is much harder and more abrasive to improve stopping performance... Will say trucks for the most part dont follow this rule as they have plenty of meat on them but of course its there for the tow rating more than anything... But back to cars higher performance cars will have more material just because they require it (fast accleration does require fast deccleration)...


But back to really what the OP is asking should you replace them uh no if you can have them turned and they are not beyond the min spec which is cast or stamped into the rotor itself... Also if the cost of turning is over 1/2 of the cost of new then it would be a better choice to buy new... BTW I get ours done for $20 per pair and its just down the street and done on a good machine by someone that knows how... I check them myself so know if they can be turned or not and of course call for new prices...

This almost sounds like its getting into a throw away thread...?


Some rotors are made from a composite material and cannot be turned. Single use only

Exotic cars only from what I have seen... Would`nt even think of not going with new...


That is very common knowledge. Cars today have to have airbags, abs, computers, thicker carpet and sound material, etc... and some just out right bigger.

Honda civic 1990 = 2000pounds while a 2006 = 2600pounds
Mustang 1967 = 2750pds, 2005 = 3600pds
Toyota Camry 1985 = 2600pds, 1990 = 2800pds, 2000 = 3000pds

and on and on...


And yes there are some aftermarket rotors that are bad. But that is better then a thin oem rotor that has been shaved down. Also many OEM rotors have had issues so even the oem is not always good.
Let alone there are plenty of aftermarket options so getting a good name brand rotor at a good price is not hard.
 

Bartman39

Elite Member | For Sale/Trade
Jul 4, 2000
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I`d bet though if you looked at the brakes on those cars you have listed the years and such the brakes of the later models would be of a lot better quality and most even in design and material and size...

No doubt the newer Mustang brakes would make the old Mustang brakes look like something off a tractor... Disk Vs. Drum

I remember the older Honda`s had a real goofy compound in their pads which looke more like brass shavings while the newer pads are of the true semi metallic type and the newer Civic`s have disk brakes in the rear as opposed to drum in the older cars... Camry is the same...


One real strange issue though is the newer Chevy trucks have rear drum brakes...? Big stuff but still old tech...?
 
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zerocool84

Lifer
Nov 11, 2004
36,041
472
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Too many people think they know more than the people who made the car. If the owner's manual says not to turn the rotors don't turn them. If the manual says to use a specific type of oil, use that. My car's manual says not to resurface them so I don't. My mom's car is newer and it says it is fine to do so.
 

Bartman39

Elite Member | For Sale/Trade
Jul 4, 2000
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Too many people think they know more than the people who made the car. If the owner's manual says not to turn the rotors don't turn them. If the manual says to use a specific type of oil, use that. My car's manual says not to resurface them so I don't. My mom's car is newer and it says it is fine to do so.


Guess you believe everything you read in the news paper and see on TV...? "tit for tat"

Now not to say you should`nt but again the manual to every car is very generic all there is to it... What type of car do you have that has a manual telling to not turn them...?
 

zerocool84

Lifer
Nov 11, 2004
36,041
472
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Guess you believe everything you read in the news paper and see on TV...? "tit for tat"

Now not to say you should`nt but again the manual to every car is very generic all there is to it... What type of car do you have that has a manual telling to not turn them...?

I drive an SRT4 and it specifically says in the manual NOT to turn the rotors at all as it will make them rotors fall under minimum spec. Owner manuals are there for a reason. They provide information for basic maintenance of the car to keep it running tip top. If you decide to not follow it then more power to you but if you follow what the owner's manual says and do the recommended service at the appropriate times, your car will last you a long time. Like I said, if the manual says not to do it then don't do it. If it says it's fine then it's fine. Don't know where there even needs to be a discussion about it. Also comparing the owner's manual to a newspaper or tv is not even close to the same thing.
 

Bartman39

Elite Member | For Sale/Trade
Jul 4, 2000
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Don't know where there even needs to be a discussion about it.

Guess what...! We do agree on something...

Dont get me started on Dodge either... Just remember I work on auto`s, trucks, heavy trucks & heavy equipment and know what is a PITA to work on...
 

Zorba

Lifer
Oct 22, 1999
15,613
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Guess you believe everything you read in the news paper and see on TV...? "tit for tat"

Now not to say you should`nt but again the manual to every car is very generic all there is to it... What type of car do you have that has a manual telling to not turn them...?

All those specs actually come from somewhere and are based on the engineering judgment and testing that OEM has.

I used to be a design engineer at a major jet engine manufacture. My company spent millions testing different oils, lubricants, etc. And testing proper servicing intervals and procedures. We also had material programs to bring new very specialized materials into existence, a new alloy program cost in the tens of millions. But a ton of our customers think they know better and use different oils and lubes and buy aftermarket parts made with inferior alloys.

The manual is generic because it does not need to change much model to model and testing is very expensive, especially if it gives you the same results you already had.
 

Bartman39

Elite Member | For Sale/Trade
Jul 4, 2000
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Only one thing left to say...

If I were to buy a car and the manual said...

When the brake pads wear out and need to be changed the rotors should not be turned but replaced...

I`d say... "Must be like a Bic lighter when it runs out of gas throw that POS away...!" EOS (End Of Story)


I mean like damn even the little Kia Soul I bought for the wife doesnt say that in the manual...?
^
 
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