Is it customary to replace brake rotors when the pads wear down? I
understand if the rotors have cracks in them, or the pads wore down to the
rivets, they'd need to be replaced or at least turned. I still had some life
left in the pads, but elected to replace them while I was in for an
inspection, and they told me that they routinely replaced the rotors at the
Well I always replace rotors!
But thats just me but heres why.
Rotors on newer vehicles arent very heavy, so generally shops
recommend on turning them so they are straight and smooth. turning
them costs money
But this maes them thinner and before you know it
rotors warp and pulsate:(
So now you need new rotors anyway and pads again.
In my case its worse I carry extra weight in my van for my
Cast iron rotors are extremely dangerous. Wrought iron is better, or
maleable cast.. A straight cast iron rotor would shatter when it hids
a puddle of ice water after hard breaking. I've seen it happen.
(Rallye Mini Cooper in the early seventies)
Through-way driving is pretty easy on brakes compared to city and
urban thoroughfare driving.
It seems to be coming more routine. Rotor are made thinner and cheaper than
in the past. If a rotor was getting grooved, it could be turned down.
Today, there is barely enough to turn and they can be replaced for $25 on
If your rotors were in decent condition, you did right in leaving them
alone. Some brake shops won't just replace pads. They insist on going a
complete change of pads, rebuilding the calipers, etc. The reasoning is
that they can then give a warranty on the entire job knowing that faulty
parts were not missed and cause a problem in a few weeks. Far more
expensive that just popping in a set of pads though.
There reasoning is that they make a hell of a lot more money. Most
people need nothing more then pads replaced on the first brake job.
I'm had many cars with the original calipers still going strong past
125,000 miles. Most brake work is a scam to move money from your
pocket to the shops pocket.
True, you might only need pads, but if the don't turn the rotors (if
they are thick enough) the pads will not seat and the brakes will not
work like they are supposed to, therefore they will not give you a
Never found seating to be a problem, but it probably can under the right
conditions. OTOH, this may save you a few bucks if the brakes are
The obvious question now is "is there a "cure" for discs with uneven
friction material deposits?" The answer is a conditional yes. If the
vibration has just started, the chances are that the temperature has never
reached the point where cementite begins to form. In this case, simply
fitting a set of good "semi-metallic" pads and using them hard (after
bedding) may well remove the deposits and restore the system to normal
operation but with upgraded pads. If only a small amount of material has
been transferred i.e. if the vibration is just starting, vigorous scrubbing
with garnet paper may remove the deposit. As many deposits are not visible,
scrub the entire friction surfaces thoroughly. Do not use regular sand paper
or emery cloth as the aluminum oxide abrasive material will permeate the
cast iron surface and make the condition worse. Do not bead blast or sand
blast the discs for the same reason
Another cure that I've not tried, is a series of about hard stops from 60 to
about 5 as hard and fast as you can. It is supposed to burn off any
So, you have brakes that are pulsating. And you're supposed to take
them apart, put on a set of new semi-metalic pads, scrub with garnet
paper, use them hard, etc. to try to fix it? Who in their right
mind would do all that instead of just buying new rotors or turning
the old ones? In my experience, a pulsating peddle is a WARPED rotor
and none of that procedure is gonna solve it. Even if it might be
capable of solving it, it's one hell of a lot more work than the
obvious and correct solution. And when it doesn't work, you get to do
it all over again.
That's your mind. Many others seem to have a different mindset. This has
been discussed frequently on auto groups and information is on various web
site. A Google search will reveal many opinions of professional mechanics
that differ from your thought.
In any case, new rotors will solve the problem.
On Sun, 17 Jan 2010 06:32:08 -0800 (PST), firstname.lastname@example.org wrote:
I agree with you in principal, but the incidence of actual WARPED
rotors is extremely low compared to pitted or collapsed rotors when it
comes to pulsations. The so-called "material transfer", or
intergranular corrosion that makes high spots or hard spots on the
rotors is much more common - as is the pitting that results when that
high spot pops off.
This intergranular corrosion and hard spotting makes machining rotors
an uncommon solution today, because generally by the time it gets to
the shop that corrosion is SO DEEP that machining it out gets you
below the machinability limit of the rotor.
If I was equipping a new automotive shop today I don't think I'd waste
money on a disc lathe because there is no way it would EVER pay for
itself under today's conditions. There was a time it was a definite
money-maker and the ability to do it inhouse rather than using a
jobber shop was a big plus.
FWIW, I have a 3/4 (or1) ton 2001 Dodge van company truck that I have
had since new. At about 47K, the chirpers on the pads started making
noise. I went to the parts house down the street from our shop, got a
set of the best pads they had, about $50, put them on myself--did
absolutely nothing but replace the pads. At about 97K, we were doing a
routine inspection onthe truck, including pulling the wheels and
checking the brakes. The pads still had probably 10-15K left on them,
but our manager had a garage we use replace them and they turned the
rotors at the same time. Truck has 125K on it now, still stopping fine,
and still has the original shoes/drums in the rear. Larry
Clare, I am in San Antonio, so no salt and mostly fairly flat roads. For
sure, 3/4-1 ton truck brake components are much heavier than modern
cars, and even 1/2 ton trucks. The pads alone for mine are about 8"
across and the lining itself is at least 5/" thick. I'm sure the rotors
are thick and heavy. The company had bought a bunch of 1/2 ton Chevy and
GMC vans before I started there--- I think they were 94-95's.They were
junk. Besides shelling the rear ends out on every single one right out
of warranty at between $800 to $1200, they did good to get 25K between
brake jobs.FWIW, I probably get more mileage out of brakes than almost
anyone there. I am the oldest one there. and am a pretty conservative
driver. Now that I think about it, I have a friend who is about 70, and
I am terrified to ride with him. He takes off from a stop just short of
burnig rubber even if he is only going one block, then slams on the
brakes just short of running a stop sign. His Lincoln Town Car gets
--maybe -- 20K between brake jobs, not to mention probably half the gas
mileage it should get. So, how a person drives has as much to do with
brake wear as the quality of the brakes. Larry
Not to mention where you live. When I lived in Philadelphia, I'd get 25,000
miles from a set of pad. Where I am now, I just traded in my '07 with
67,000 miles and the brakes were in very good condition, close to half the
pad left. I put on more miles per y ear, but hit the brakes much less.
Instead of a stop sign at every corner, I can drive home 25 miles and hit
the brakes two or three times.
yeah, I never actually wore out a set of brakes before I moved to
DC-land. Before that, I'd do a brake job when I bought a "new used" car
and they'd last until the car wore out or I got sick of it.
replace "roosters" with "cox" to reply.
On Sun, 17 Jan 2010 21:14:14 -0600, email@example.com (Lp1331 1p1331)
San Antonio is likely one of the best places to live for brake life.
You have no road salt and relatively low humidity, so corrosion is not
a big concern, and you are not a "large municipal region" like the LA
basin, so have less Urban Gridlock. Much of your driving would be
relatively open road, except during rush-hour. (comparing to, say, the
wachington DC area, NYC, Toronto, or Montreal or even Vancouver - or
Dallas/ft Worth) - and like you say - FLAT - kinda like Saskatchewan -
where you can watch your dog running away for a week.
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