I had one brake rotor which was scarred. The mechanic told me to
replace the rotors costing another $100 more. I asked if the rotor
could be machined (about 3/16 inch). He said yes. The rotor on the
other side looked fine, but he told me that it too needed to be
machined. It had a slight unevenness which could be removed by
removing at most 1/16 of an inch. He told me that both need to be
machined otherwise the brakes would not grip evenly? Is that true, or
is he just trying to milk more money out of me?
=?x-user-defined?Q?=AB?= Paul =?x-user-defined?Q?=BB?= - 17 Sep 2006 02:34 GMT
> I had one brake rotor which was scarred. The mechanic told me to
> replace the rotors costing another $100 more. I asked if the rotor
[quoted text clipped - 4 lines]
> machined otherwise the brakes would not grip evenly? Is that true, or
> is he just trying to milk more money out of me?
It is best to do both but not absolutely necessary.
OTOH, I would not even bother machining the rotors on your 2005 Pontiac Grand Am.
Just replace them instead.
Scott Dorsey - 17 Sep 2006 15:12 GMT
>I had one brake rotor which was scarred. The mechanic told me to
>replace the rotors costing another $100 more. I asked if the rotor
[quoted text clipped - 4 lines]
>machined otherwise the brakes would not grip evenly? Is that true, or
>is he just trying to milk more money out of me?
These days, I suspect it may be cheaper for you in the long run just
to replace the rotors. Yes, it costs a little more than resurfacing,
but it'll last longer.
And yes, if one needs to be machined or replaced, almost certainly they
both do.
Don't fool around with brakes. When brakes fail, people die.
--scott

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"C'est un Nagra. C'est suisse, et tres, tres precis."
Kaz Kylheku - 18 Sep 2006 02:08 GMT
> I had one brake rotor which was scarred. The mechanic told me to
> replace the rotors costing another $100 more. I asked if the rotor
[quoted text clipped - 4 lines]
> machined otherwise the brakes would not grip evenly? Is that true, or
> is he just trying to milk more money out of me?
The most common reason why rotors have to be replaced is that they have
been machined too many times. The brake shops love to do that because
they get to sell you new ones the next time you come back.
Each time you machine a perfectly good rotor, you are taking tens of
thousands of miles off it.
Grooves that are not too deep are acceptable.
Glaze can be removed with a light sanding, rather than a full machining.
Al Bundy - 18 Sep 2006 13:59 GMT
> > I had one brake rotor which was scarred. The mechanic told me to
> > replace the rotors costing another $100 more. I asked if the rotor
[quoted text clipped - 15 lines]
>
> Glaze can be removed with a light sanding, rather than a full machining.
Rotors can be worn beyond specs and never have been machined.
jeffcoslacker - 18 Sep 2006 18:09 GMT
Al Bundy Wrote:
> > > I had one brake rotor which was scarred. The mechanic told me to
> > > replace the rotors costing another $100 more. I asked if the rotor
[quoted text clipped - 20 lines]
>
> Rotors can be worn beyond specs and never have been machined.
Yep. Most FWD cars' rotors are made with a minimum of meat in the first
place...machining will often take them below spec the first time, and
even if not, leaves them susceptible to developing stress related
warping and cracking later...just throw a new pair on it...and be sure
they put a non-directional finish on the new ones, for faster seating
of the new pads and better stopping power, along with reduced noise
problems...a lot of the new ones we installed were generating
complaints from the start until we began putting a swirl on them before
installing....

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jeffcoslacker
http://www.automotiveforums.com
sdlomi2 - 19 Sep 2006 06:04 GMT
> Al Bundy Wrote:
>> > > I had one brake rotor which was scarred. The mechanic told me to
[quoted text clipped - 31 lines]
> complaints from the start until we began putting a swirl on them before
> installing....
Hey 'jeff' that's interesting. How do you put that non-directional
finish on them? Thx in advance for the info. s
John S. - 18 Sep 2006 17:41 GMT
> I had one brake rotor which was scarred. The mechanic told me to
> replace the rotors costing another $100 more. I asked if the rotor
[quoted text clipped - 4 lines]
> machined otherwise the brakes would not grip evenly? Is that true, or
> is he just trying to milk more money out of me?
Rather than machining, I would just replace both rotors.