Oddly, both the authors of the factory service manuals for my cars, and the
mechanics who have machined rotors for me in the past, don't agree with you.
Stick to subjects you know something about. This isn't one of them.
Obviously it didn't teach you very much -- if you even have it, which (based
on your silly claims) I rather doubt. I have to assume that the guys that
wrote my factory service manual know just a little bit more about what should
or should not be done on their vehicles than you do.
Well, if you are saying it is federally mandated safety standards you
are only PARTLY right.
Federal law requires the minimums (or maximums)to be permanently
inscribed (or otherwise attached) to the rotor (or drum) in question,
but has NO input into what that minimum (or maximum) measurement is.
That is determined by the materials engineers at the manufacturer.
If what you are saying is that ONLY solid rotors should never be
machined, you are not even PARTLY right.
Both solid and vented rotors can often be safely machined to within
very close to the minimum - and both solid and vented rotors can be
caused to warp or pulsate due to that machining - and in a VERY LARGE
NUMBER of cases, replacing the rotors with new (either aftermarket or
OEM) rotors can be done for anywhere from slightly more to slightly
less than the cost of machining.
One instance where machining was definitely cheaper was the pressed
together hub/rotor/bearing assemblies as used on the early (1978-82?)
Toyota tercel (and several other front wheel drive cars) where, with
proper equipment, you could machine the rotors ON THE CAR, while
replacement, (or off car machining) was something close to an hour's
job with the right tools, and closer to 2 hours without.
And these rotors were SOLID, not vented rotors.
What I did as service manager at that time was give the customer the
choice - machine on car, or replace - with the pricing stated both
ways, and a guarantee that if the rotors thumped within 15 days I
would apply half of the cost of machining towards the cost of
replacement.. I did not offer off-car machining of those Tercel rotors
If they could not be machined within spec, there was no charge for the
on-car turning, and they had to be replaced.
Under warranty, any brake pulsation REQUIRED the rotors to be machined
- either off car or on car - and the on-car lathe paid for itself
several times over in the first year on warranty jobs alone.
And 30 years of ASE certification is peanuts.
After you install new rotors, get the old ones machined, oil them up, put them
in the boxes the new rotors came in, and put them on a shelf somewhere. Then
you'll have them ready to install the next time you need the rotors machined.
Repeat as needed until the rotors are no longer machinable.
They were used on my Acura Integra GS-R,and I have them on my Nissan Sentra
SE-R Spec V.
What else is used to hold on the rotors when the wheel is off??
wouldn't bolts would stick out,interfere with mounting the wheel?
BTW,there's probably two other holes in the rotor "top hat",that those
screws thread into for helping push the rotor off the axle flange if it's
so you don't have to hammer on the rotor to loosen it from the flange,or
use a giant "gear puller". :-)
On my wife's (and son's) Taurus, *nothing* holds the rotors on when the
wheel is off...other than rust of course.
The rotors can't be removed until the caliber bracket is removed, but
that's only because the bracket is in the way.
Once the caliber bracket is removed the old rotor just slips off of the
hub and the new one slips on in it's place.
I can't recall what other cars I've worked on that had no mechanical
means of attaching the rotors, but the Odyssey is the only one I've seen
that had screws.
There may be other holes but not for *those* screws. Those screws are
too short (1/2"?) to be used to force the rotors off.
Beside, a Phillips head screw wouldn't be the right screw for the job.
It would have to be a bolt with a head so you could put some torque on it.
they have to be long enough to go through the rotor and into the axle
flange. thus,long enough to push off the rotor in the other holes.
It doesn't take much to break the rotor "top hat" loose.
ISTR it worked for me. it doesn't take much to get it loose.
the Civic/Integra Haynes manual said to use two bolts,not the original
I might have used the caliper bolts,I don't recall. I know I didn't have
two spare bolts that fit.
That's true, but I don't recall any other counter-sunk holes in the
rotor. The holes would need to be counter sunk for the Phillips heads to
go through the rotor and contact the flange.
Maybe when I get done with today's projects I'll pull a wheel and see.
On Sat, 02 Jul 2011 12:32:39 -0400, email@example.com wrote:
If he's getting shop prices for new rotors vs turning, turning will be
cheaper due to rotor markup.
If you do your own work, it might or might not be cheaper to buy new,
depending on the car.
In my experience new rotors is the way to go.
For my GM cars new rotors are $15-40, depending on brand.
I've looked at the cheap and the more costly, and they look the same
to me, so I go with the cheap.
Basically they all come from the same Chinese rotor plants.
Both front rotors cost less than a good pad set.
Front rotors for my daughter's Mitsu Eclipse cost about $30 each.
You have to price by the car.
Wouldn't think of cutting old rotors.
And I've seen BS advice that brand new rotors should be turned.
Can't remember where.
No way I'm going to give a new factory rotor to a kid to shave.
I just clean the preservative off them.
On my Celebrity I put new rotors on when they pulsed due to warping.
That was at about 150k miles.
I had put about 3 sets of pads on the old grooved rotors, starting at
about 50k miles.
Worked fine, braked evenly, but of course the grooves got deeper
and the last pad set wore pretty fast.
Some cars might not tolerate that.
If I knew how cheap rotors were I'd have replaced them earlier, then I
wouldn't have had to bang them off with a sledge.
With cheap rotors now, cutting rotors is a vestige of the past when a
rotor cost +$100 in 1980 dollars.
To prevent warping torque your tires properly and don't run through
puddles with hot rotors.
And there is NEVER cast iron used on an aotomotive hub. Cast steel,
possibly. You will NEVER break something, other than the cheap
screwdriver bit, by using the impact driver to attempt to remove the
rotor or drum retaining screws.
A certified mechanic has the specs on rotor thickness and tolerance. They
should be aware of how much is removed from resurfacing resulting in the
minimal thickness allowed. A thinner rotor does have the potential to warp
easier, but not exceeding the minimal thickness will not be that great.
Also, not riding the brake or keeping depressed after a stop will retain the
heat and add to the potential warping. If people learn to press and release,
they will save their rotors and pads much longer.
The VAST majority of "thumping" rotors are NOT warped - but the press
and release IS critical. When disk brakes are used, part of the pad
material is transferred to the rotor - basically burnishing it - and
after a hard stop, if the pads remain clamped to the rotor, more pad
material can transfer to the rotor.. This causes a brake pulsation
next time the brakes are used - and can OFTEN be cured by riding the
brake for a short time to re-heat and distribute the lining material
on the rotor..
In salt areas corrosion often starts under the deposited pad material
- particularly the "lumps" and the rotors pit behind the "glaze" -
causing permanent thumping - most often too deep to be machined out
Virgin rotors are not that expensive. One main cause of warping is poor
torquing of lug nuts. My brakes last at least 120K miles. I only brake
to stop moving. Idiots always hurry up and brake, hurry up and brake. I
can't understabd them. How many of them are here?
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