Must Replace rotor?
#1
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Don1954 (09-13-2018)
#3
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Most dealerships will claim that the rotors also need replacing every time the pads are renewed.
They usually claim "for maximum braking efficiency and peace of mind you need to renew both at the same time".
IMHO and after lots and lots of research and experience across two XFs and the F-Type this is BS and simply a standard con from the dealership to generate more revenue from unnecessary rotor replacement. I had the OEM rotors on both the XFS and XFR turned/machined when fitting new pads the first time (not long after I bought each car) and not a single problem, the brakes worked perfectly afterwards.
As we know the OEM brake pads on the F-Type wear fairly quickly and so do the rotors, as they are both fairly "soft", and a good portion of the massive amounts of brake dust you get with OEM pads and rotors is actually from the rotors not just the pads.
But in 99% of cases you should easily get two fully worn out sets of pads out of one set of rotors.
The idea is to measure the rotor thickness (all four) when you are ready for a pad change and determine if the rotors are within minimum thickness spec or not.
If they are thicker than minimum spec you are good to go for another set of pads, if under minimum specified thickness then at least for insurance purposes you should renew the rotors as well.
According to the Workshop Manual the specified minimum thickness for all Jag rotors is 2 mm less than new.
For example with the F-Type "super performance" brakes (380 mm front and 376 mm rear) front new rotor thickness is 36 mm / 1.42" and minimum thickness is 34 mm / 1.34" while rear new rotor thickness is 26 mm / 1.02" and minimum thickness is 24 mm / .94".
So JLR are saying that 2 mm of wear or a whopping 1 mm each side takes them to minimum specified thickness, which IMHO is excessively pessimistic and the rotors are almost certainly still perfectly OK at another 2 mm thinner, especially the fronts.
But of course you take a risk running rotors slightly under minimum specified thickness that the insurance company might deny a claim.
Bottom line - don't take the dealer's word for it, measure the thickness of all four rotors yourself (very easy to do with a vernier caliper) and then decide if you want/need to replace them. If you decide to keep them it is always a good idea to get them skimmed when fitting new pads.
They usually claim "for maximum braking efficiency and peace of mind you need to renew both at the same time".
IMHO and after lots and lots of research and experience across two XFs and the F-Type this is BS and simply a standard con from the dealership to generate more revenue from unnecessary rotor replacement. I had the OEM rotors on both the XFS and XFR turned/machined when fitting new pads the first time (not long after I bought each car) and not a single problem, the brakes worked perfectly afterwards.
As we know the OEM brake pads on the F-Type wear fairly quickly and so do the rotors, as they are both fairly "soft", and a good portion of the massive amounts of brake dust you get with OEM pads and rotors is actually from the rotors not just the pads.
But in 99% of cases you should easily get two fully worn out sets of pads out of one set of rotors.
The idea is to measure the rotor thickness (all four) when you are ready for a pad change and determine if the rotors are within minimum thickness spec or not.
If they are thicker than minimum spec you are good to go for another set of pads, if under minimum specified thickness then at least for insurance purposes you should renew the rotors as well.
According to the Workshop Manual the specified minimum thickness for all Jag rotors is 2 mm less than new.
For example with the F-Type "super performance" brakes (380 mm front and 376 mm rear) front new rotor thickness is 36 mm / 1.42" and minimum thickness is 34 mm / 1.34" while rear new rotor thickness is 26 mm / 1.02" and minimum thickness is 24 mm / .94".
So JLR are saying that 2 mm of wear or a whopping 1 mm each side takes them to minimum specified thickness, which IMHO is excessively pessimistic and the rotors are almost certainly still perfectly OK at another 2 mm thinner, especially the fronts.
But of course you take a risk running rotors slightly under minimum specified thickness that the insurance company might deny a claim.
Bottom line - don't take the dealer's word for it, measure the thickness of all four rotors yourself (very easy to do with a vernier caliper) and then decide if you want/need to replace them. If you decide to keep them it is always a good idea to get them skimmed when fitting new pads.
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Valerie Stabenow (05-27-2024)
#5
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Don1954 (09-13-2018)
#6
That hasn't been my experience, at least on the street. Porterfield pads seem comparable to OEM but with 70% less dust, initial bite is a little less than OEM (which is a good thing on F type - I hated the grabbiness at slow speeds) and I have not experienced noise with them on either my F type or my M3. But hey, as they say, YMMV.
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#7
Don,
I concur with OZ that new rotors are unnecessary unless you are pushing 50 or 60k miles. No one will turn the rotors, as the brand new spec is probably identical to the minimum spec in the maintenance book. Even if your rotors have a few minor ridges in them, the new pads will conform perfectly within a couple hundred miles.
I concur with OZ that new rotors are unnecessary unless you are pushing 50 or 60k miles. No one will turn the rotors, as the brand new spec is probably identical to the minimum spec in the maintenance book. Even if your rotors have a few minor ridges in them, the new pads will conform perfectly within a couple hundred miles.
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We are missing critical details here that would be needed prior to our ability to formulate an appropriate response. How many miles are on the car now and have you engaged in any "excessive" wear and tear during that period? If you are a typical "spirited" driver who may occasionally travel some twisty mountain roads then you may need to replace the rotors at 50K or 60K. If you "drive like my 99 year old grandma did never exceeding 45MPH in a one-stop light town on the flat plains of Iowa (Seriously, she lived in Cresco IA & still drove @ 99 years young ) then you may be able to put 100K miles on it before needing rotors. If, on the other hand, you are tracking it on a weekly basis then perhaps the rotors "might" need to be replaced in as few as 25K miles so... What is the current mileage and which type of driver are you?
#9
The OP (Don) stated that the pads are not worn out, he just wants a less dusty pad/wheel.
Of course, the most accurate response is to 'measure rotor thickness first, then decide for yourself'. If a dealer won't do it that way, go to an independent shop. (Which I would do anyway, its not a warranty situation at all...)
That said, I think that Jaguar's conservative wear specs are because the rotor DOES contribute to heat dissipation. If it's too thin you are on 'thin ice' to coin a phrase.
Even if you really want to get your money's worth, don't let yours wear this far, OK?
Or
Of course, the most accurate response is to 'measure rotor thickness first, then decide for yourself'. If a dealer won't do it that way, go to an independent shop. (Which I would do anyway, its not a warranty situation at all...)
That said, I think that Jaguar's conservative wear specs are because the rotor DOES contribute to heat dissipation. If it's too thin you are on 'thin ice' to coin a phrase.
Even if you really want to get your money's worth, don't let yours wear this far, OK?
Or
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Don1954 (09-17-2018)
#10
At least part of this is the dealer is covering themselves in case of a come-back. If they replace the pads only and the brakes have issues, such as squealing, they'll have to do the job again on their own dime.
I never turn rotors, but also do my own brake work. I save on labor, and replace rotors with pads because I don't want to go back in. I've got more interesting things to do with my time. I may feel differently with my expensive two-piece rotors when the time comes, but my micrometer will have the final say.
I never turn rotors, but also do my own brake work. I save on labor, and replace rotors with pads because I don't want to go back in. I've got more interesting things to do with my time. I may feel differently with my expensive two-piece rotors when the time comes, but my micrometer will have the final say.
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Don1954 (09-17-2018)
#11
#12
At least part of this is the dealer is covering themselves in case of a come-back. If they replace the pads only and the brakes have issues, such as squealing, they'll have to do the job again on their own dime.
I never turn rotors, but also do my own brake work. I save on labor, and replace rotors with pads because I don't want to go back in. I've got more interesting things to do with my time. I may feel differently with my expensive two-piece rotors when the time comes, but my micrometer will have the final say.
I never turn rotors, but also do my own brake work. I save on labor, and replace rotors with pads because I don't want to go back in. I've got more interesting things to do with my time. I may feel differently with my expensive two-piece rotors when the time comes, but my micrometer will have the final say.
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Dillweed (05-27-2024)
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Don1954 (09-17-2018)
#14
I enjoy keeping up the appearance of my car, but that doesn't include having to clean the wheels after a 10 mile jaunt! The amount of brake dust the car creates is insane.
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Jdwoody17 (05-30-2024)
#16
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Don1954 (09-17-2018)
#17
you might look into coating wheels with ceramic (cquartz, opti-gloss,etc) to reduce brake dust sticking, and use wheel cleaner like Sonax or Griots heavy duty.
#19
The ceramic coating does work with brake dust
I used Avalon King ceramic on the car and after wasting bottles of wheel cleaner, I finally wised up, cleaned and IP alcohol wiped the wheels and put some AK on them, too. Now all I have to do is car soap them up, take a detail brush and work it around all the little corners, rinse and all good.
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peppersam740 (05-29-2024)