How often do you need to change brake rotors?

Discussion in 'The Garage' started by spikespiegal, Nov 18, 2008.

  1. spikespiegal

    spikespiegal Golden Member

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    99% of the time I go to a mechanic, dealership, etc., to have periodic brake work done they tell me I need to get new rotors. Doesn't matter what brand of car I have because I've owned many makes and models over the past 20 years. I've grown accustomed to being told 'you need new rotors' no matter what. Even of the rotors aren't scored or warped, they always manage to make an excuse that I need new rotors, and hence my bill goes from $200 to $800. Only once in the past 20years has a service dept ever offered to even turn the things. I always 'need new rotors'. Acura, Nissan, Honda, Chevy.....50,000-150,000 miles. I "always need new rotors".

    I've changed by own brake pads/rotors on cars in the past and simply don't have the time, but not being a mechanic I can't really respond to somebody with my car on a hoist and pulled apart and claiming the every tiny groove on my rotor means my car is unsafe to drive and I need new rotors. Case in point, the brakes on my Mazda M3 with 65,000 miles have just started to squeek, which obviously means the pads need to be changed, but I dread going to a mechanic and have them tell me "I need new rotors". Given my mood and the economy, if they are simply trying to screw me, they are going to pulling their impact wrench out of a certain orifice.

    How often do you really need new rotors?
     
  2. OCGuy

    OCGuy Lifer

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    Its a big scam. Take it to someone you trust. Much of the time they can resurface them.
     
  3. PottedMeat

    PottedMeat Lifer

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    You've said 'yes' every time???
     
  4. PlasmaBomb

    PlasmaBomb Lifer

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    Buy a micrometer and measure the thickness of the rotors. Check it against the specification, if they are too thin they need replaced (baring warping or some other defect which would necessitate them being changed early).
     
  5. PlasmaBomb

    PlasmaBomb Lifer

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    PS.

    <------------------------ Garage
     
  6. Bulk Beef

    Bulk Beef Diamond Member

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    You could ask them to show you the spec in the manual, then show you the measurement, then watch the guy at the service counter go "uhhhh, let me talk to my manager."
     
  7. bruceb

    bruceb Diamond Member

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    Interesting this topic came up. Today I just did the brakes on my 1999 Grand Prix and the Front Rotors were in need of replacement .. More wear on the inside edge that you can't really see. Compared to the new Brembos, they were definitely worn to the point of needing replacement. Now I do not recall if they were changed once before or not. But the mileage today was at 178K .. I think I changed them once before, but on average, a set of rotors should last 2, maybe 3 sets of pads... Except on high erformance cars, like BMW or Mercedes ... Had new rear pads put in also ... Inboard pads were totally at the limit. All told it was $130 for rotors, $80 for front pads (already had rear pads, but they run about $40) and $500 labor, which included 2 new P6 tires .. Nice thing on the Brembo rotors, they have a built in Wear Indicator .. when you see only 1 dimple or none, time to replace them. Easily checked thru the wheel.
     
  8. Vette73

    Vette73 Lifer

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    Older rotors were thicker and could be turned without little effect. But a lot of cars come with rotors that are thinner then old ones and the wheel puts pressure on them when you tighten the lug nuts. When I had my shop I would not turn most newwer cars and some truck rotors as there was a high chance of them warping much easier let alone the fact that new rotors do not cost that much for most cars.
    I got a full set of 4 rotors for my CTS for a little over $100 and that was for a zinc coated, drilled, and slotted set.


    Now a lot of shops they way they have the system set up a tech makes more money selling new rotors then turning the old ones. For me it was a wash as I did not really mark up my parts so there is little labor in installing most newwer rotors but turning them was.
     
  9. PottedMeat

    PottedMeat Lifer

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    I think everyone should buy the factory service manual for their car. They're easy to read and tell you exactly what you need to do. I'd get a set of digital calipers too at ~$16.
     
  10. alkemyst

    alkemyst No Lifer

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    QFT rotors can be measured in millimeters...no need for expensive calipers...even a ruler can be used if they don't have a lip.

    Only need to replace when they are out of spec...also you don't need to have them turned everytime either...this is a trick to wear out rotors quick.
     
  11. fstime

    fstime Diamond Member

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    From what I hear, turning rotors is much more uncommon now because rotors that are turned can become too thin and then heat up much faster and warp much easier.

    Whats the point of turning them anyways, $20/rotor to turn vs $40-60 for a brand new rotor.


    Anyways, I usually go by feel, you can tell if your rotors are warped, if you really want to make sure, measure them. Remember, bad brakes can result from a stuck caliper, unevenly worn pads, and many other factors.
     
  12. T2urtle

    T2urtle Diamond Member

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    ^ same...

    on my cars i go by feel, and age. but honestly you never know until you take off the wheel.

    VW i know for a fact will NOT cut rotors because thats how they make it, very thin specs, not sure for weight savings or any other reason.

    most people tend to wait too long to do brakes, the last 3 brake jobs i did for people I've found METAL to METAL, where it grooved the rotors a lot, must replace at that point. I normally just go by feel tho, i've also found out the shop down the block from me cuts rotors at 10$ piece. So i might opt to go there if i feel some warpage.
     
  13. alkemyst

    alkemyst No Lifer

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    myth...

    not all rotors will only set you back $40-60 though. I can get rears for about $50 a pop...my fronts are about $200 each at the low end. Rotors should be closer to $20 turned for the set than each. If you aren't taking them off yourself, chances are you won't be getting $40-60 rotors either.
     
  14. bruceb

    bruceb Diamond Member

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    Rotors for my Grand Prix (Brembo .. not drilled or slotted) were $60 each at Tirerack.com . This is a decent brand.
    Of course for a high performance car, expect that rotor to be heavier, drilled, slotted & run about $120 each & up.
     
  15. Pacfanweb

    Pacfanweb Lifer

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    Whenever your rotors are at or below minimum thickness, to answer your question. It's very possible, and common, even, for rotors to wear out along with the pads, particularly if your pads last a long time.

    Just because they're not grooved doesn't mean they're not worn. And if they're at or close to the minimum thickness, you can't machine them.
     
  16. alkemyst

    alkemyst No Lifer

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    They can easily be much more and not drilled or slotted. Weight is not so much a factor as size and material
     
  17. bruceb

    bruceb Diamond Member

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    Yes, quite true. Luckily most passenger cars at not too expensive for the rotors. SUV / Trucks would be much more, as would
    for say a Camaro /.GTO / Vette type or car.
     
  18. alkemyst

    alkemyst No Lifer

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    Vette maybe, Camaro and GTO aren't running that special of rotors. At least Camaros aren't
     
  19. herm0016

    herm0016 Diamond Member

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    you also have to watch the vented rotors, the webbing can rot away in the center. i just replaced my brakes and rotors, the webbing had lost at least 1/3 of its thickness to rusting and rot.
     
  20. Elstupido

    Elstupido Senior member

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  21. zerocool84

    zerocool84 Lifer

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    Many newer cars advise not to machine the rotors just fyi. Check the owners manual or an internet forum for advice on your specific car.
     
  22. PlasmaBomb

    PlasmaBomb Lifer

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    Wot?

    You are broken??
     
  23. alkemyst

    alkemyst No Lifer

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    He was talking about the edited post above him.
     
  24. StageLeft

    StageLeft No Lifer

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    My experience:

    *Maxima*
    FRONT: felt vibrating while braking; rotors were not "warped", but had some buildup on them. Replaced pads and had rotors turned. The rotors finally became rusted up and unusable 50k later so I replaced them. Got 110k out of the rotors with one turning.
    BACK: heard squeeling around 60k mark. Replaced the pads. Didn't even turn the rotors. They squeeled for 10k until they bedded properly and recently at 119k total--so almost 60k extra, I replaced both the rotors and pads. Got 119k out of the rotors with no turning.

    *MPV*
    FRONT: 60k my front I replaced because I thought they were the cause of vibrating (turned out it was the rear). Rotors had tiny marks in them, but since they were cheap I simply replaced them with the pads.
    REAR: 60k the rotors were basically finished, so I replaced them.

    Understand that I do this all myself and since rotors are cheap $85 a piece for the rear of the MPV, but on the front and all on the maxima they're around $40-45 each, I have a tendency to simply replace them. Not that I won't think about turning them in the future, but $60 saved to ensure new rotors are there is ok with me.

    FWIW, once the wheel is off and the caliper pins regreased, it's really menial a task to take the rotors off (two bolts and a rubber mallet), so it's not like there is much extra labor, although I know shops like to grab you for what they can. That's why I find the time to repair my car. I hate paying others for that stuff.
     
  25. overst33r

    overst33r Diamond Member

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    If they vibrate even a tiny bit, in my experience machining/turning rotors is just a temporary fix. The vibration will be back.