Bryan,
Hard spots can be really hard! Many times they can be machined with a
lathe tool, but more often they require grinding. Lots of shops don't
have the capability of grinding rotors, (I am not referring to sanding
for bi-directional patterns, but actually resurfacing by grinding
instead of a lathe tool) that is why they replace them. If the hard
spots are not properly machined, various kinds of braking problems
result and some these can be dangerous. When working on brakes always
choose the safest approach, even if it gets expensive.
Number one priority when hard spots are encountered is finding out WHY
they are there. Most of the possible reasons have already been
mentioned. I have found that the most common problem is because of
calipers that are not operating freely causing a brake pads to not
return properly allowing a constant drag.
Tom, Redding CA - #216 D/CC
Bryan Savage wrote:
> Doc,
>
> Are "hard spots" real hard?
> Doesn't it require grinding the surface?
> My OEM rotors only have 0.075 left. (0.005 wear). Doesn't seem like
> much..!.?..
>
> Oh well, I have learned a lot of good stuff that I kind of wish I didn't
> need to know.
>
> Thanks anyway,
> Bryan
>
>
> docb8532@aol.com wrote:
>
>> In a message dated 6/2/04 1:39:08 PM Eastern Daylight Time,
>> albaugh_neil@ti.com writes:
>>
>> That's why most brake experts
>> replace rotors that have developed hard spots."
>>
>> We turn them on a regular basis. Don't remember the last time one
>> came back. This is an industry wide MAP aproved standard repair. If
>> it's done right, the calipers are working right, and the wheel nuts
>> are allways torqued properly we just don't have problems. It's not at
>> all uncommon to see these spots in rotors purchased from any source.
>> Selling a customer rotors when machine work is a reasonable option is
>> an unethical practice and most experts don't replace rotors when this
>> situation exists.
>> Doc
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