Warpped Rotors
Al Peterson
Explorer 4X4.
Now the rotors are warped (I guess that's the problem) and braking above 45
MPH results in a shuddering sensation. What are the chances of being able
to turn the rotors to true them up. Should I just bite the bullet and buy
new rotors?
--
-= Al =-
Al Rolle
order)If they are in spec, then sand the discs with about 80 grit paper.
Clean with alcohol. I also sand the pads and clean with alcohol.
My Explorer shop manual recommends the sandpaper treatment and indicates
that rotors rarely get warped.
If they are out of spec then they can probably be turned if they are not too
warped.
In the 45 years I've been driving, I've never had warped drums or rotors. Of
course, I take my torque wrench with me when I get new tires and insist on
either they use the torque rods or my wrench when they tighten down the lug
nuts.
If you take it to a brake shop before you check for run-out, you will have
wrapped rotors by definition.
Al
"Al Peterson" <NOSP...@mpinet.net> wrote in message
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Buck-n-Neece
lathe to be made parallel again.
"Al Rolle" <al.r...@worldnet.att.net> wrote in message
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Jack Dannenberg
nowhere does it say to try and true the rotors with sandpaper.
"Buck-n-Neece" <dry...@cybertrails.com> wrote in message
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Al Rolle
spec or not.
Al
"Buck-n-Neece" <dry...@cybertrails.com> wrote in message
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C. E. White
like they are warped because the friction characteristic of the rotor
have been changed in a small area. This can give brakes the "feel" of a
warped rotor. It is usually caused by a hard application of very new
brake pads. During the first few hundred miles after new pads are
installed it is possible that a sudden, hard stop will physically
transfer lining material to the brake rotor in a small area. This become
less likely as the pads "bed-in." If lining material is transferred to a
small area of the rotor, this area will have a different coefficient of
friction and the braking force will change as this area rotates under
the pads. It will feel very similar to a warped rotor. Sanding the
rotors and cleaning them with alcohol may correct this problem.
The original advice to check the run-out of the rotor with a dial
indicator and then sand/clean the rotors if they are within spec is
exactly the right thing to do.
Ed
Buck-n-Neece
left to machine them parallel and true.
"Jack Dannenberg" <cad...@worldnet.att.net> wrote in message
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Robert
Not lubricating the slide pins shouldn't have caused your rotors to
warp unless your pins were in real bad shape. The first time I
lubricated mine on my '97 4x4 was at about 30K miles when I noticed a
moaning noise when idleing forward from a stop. It sounded like the
pads were hanging up, but once I got above 5MPH the noise went away.
They would probably have to drag almost to the point of preventing your
Explorer from moving forward at idle when you took your foot off the
brake. The other thing that can cause warping is not using a torque
wrench on the lug nuts. You don't have much to loose by having them
turned. All of the places I checked wanted $5 each to turn them when I
did my brakes. So at $10 for the fronts, it would be worth it to me to
find out before spending a lot more for new rotors. Mine weren't warped
so they just measured mine to be sure that I had enough material. Ford
also turned my front rotors once before thinking that was the source of
my noise so my rotors were turned twice and were still above the
recommended minimum thickness. The next time though, I'll have to buy
new front rotors.
--
Robert
Al Rolle
away) the disc life.
I recently replaced my Volvo front disc's at 100,000. They had probably
another 10,000 to 20,000 left. I wouldn't have achieved that kind of wear if
I needlessly had them turned. They were well within runout specs when I
replaced them. They were just getting thin. I also installed my third set of
front pads. The rear discs are probably good for another 100,000 plus.
I have 105,000 on my Explorer front disc's. Runout is well within specs and
they have probably another 40,000+ of life left. The surface scouring is
well within acceptable range, as were the Volvo discs when they were
replaced.
Al
"Robert" <reber...@qwest.net> wrote in message
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Jack Dannenberg
that indicates if they are warped. There is a spec for that as well as
thickness.news:7zn66.2000$i25.6...@mick.cybertrails.com...
Jack Dannenberg
Trend or Road & Track did an investigation into what causes warped rotors.
Their conclusion was that the biggest cause of warped rotors was that the
manufacturers used too small of rotors for the size of the vehicle. They
believed that incorrect torqueing of wheel nuts was a minor contribution.
I'll keep torqueing my wheel nuts just to be safe.
Jack Dannenbergnews:e5p66.6441$fj6.5...@bgtnsc05-news.ops.worldnet.att.net...
Al Rolle
any tire shop change air pressure or wrench settings (or use torque rods) as
they switch to different vehicles.
I agree, my Volvo discs/mountings are not strong enough for 140 ft-lbs.
Since I demand that my wheels are torqued properly and stay and watch them
do it, I've never had warped discs/drums. I think that's a good indication
that the discs are strong enough for road use/abuse.
By the way, I badly smoked all four of my old '84 BMW brakes doing a "test"
from an indicated 115 mph. Stopped as fast as possible. Thought for sure the
rotors would have to warp. Runout was perfect. Something like .002" if I
remember correctly.
A caliper locked-up on my 3/4 ton. It brought the vehicle to a stop. The
disc/caliper and about everything else on that wheel was cherry red. No
warpage. I did replace everything though, including the rubber brake line.
Al
"Jack Dannenberg" <cad...@worldnet.att.net> wrote in message
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Al Peterson
indicator to check the rotors on my Explorer?
Thanks
--
-= Al =-
"Al Rolle" <al.r...@worldnet.att.net> wrote in message
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Al Rolle
rods, clamps set (needed to hold gauge, #81AS22467A) 19.95.
Trouble with JCW is that they charge high shipping for small orders. Like 5
to 9 dollars for this one, depending where you live.
Al
"Al Peterson" <NOSP...@mpinet.net> wrote in message
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Just Me!
shakes and took it in, since it was under warranty. The mech said the
rotors were warped and he could turn them to take care of the problem.
Well, I did not have much time so I said I would schedule an appointment
for later the next week. Two days later a friend told me to check my
front tire pressure(s) and if uneven pressure it can cause a like
condition. Well, I checked and found the left front tire to be two
pounds less than the right front tire and when I equalled the pressures
and drove it..guess what....yep, the shakes disappeared..........and
since I did not get the rotors turned or replaced and I've put 47K miles
on the car since then I would have to say that the uneven pressure was
in deed the problem (leastwise in my case). So, check your tire
pressures before you go for the warped rotor diagnosis.
"AZGuy" <jim...@earthlink.net> wrote in message
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> My rotors warped in the first 3000 miles of ownership. During that
> time the brakes were never worked hard. Personally, I don't think
> "undersized" rotors has anything to do with the warping problem per se
> or mine would never have warped in that short 3000 mile light use
> period. After having the amount of "shake" increase tremendously
> following a wheel balance I'm pretty convinced that improper torquing
> of the lug nuts has a lot to do with the warping. In addition it
> would seem to me that if tightening down the lug nuts can have such a
> large influence on the "shape" of the rotors, that the basic issue
> with warping is that the rotors are just not mounted on a stout enough
> "mount" to maintain their geometry. So the basic problem that I see
> isn't undersizing of the disk itself as just plain poor design of the
> overall brake/hub/wheel "system".
Robert
"Al Rolle" <al.r...@worldnet.att.net> wrote:
> My Volvo requires 63 ft lbs, my 3/4 ton Van requires 140. I've never
seen
> any tire shop change air pressure or wrench settings (or use torque
rods) as
> they switch to different vehicles.
I don't think it is as much an issue with the actual setting as it is
that all the lug nuts get the same amount. It's when someone uses an
impact wrench (without the rod) it is not consistent in the torque
applied. Same goes with using a breaker bar. At least using a torque
wrench, regardless if the setting is correct, will put the same torque
on all lug nuts.
Al Rolle
know.
Al
"Robert" <reber...@qwest.net> wrote in message
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FS
resulting in excess heat generation during braking. If the lug nuts are not
torqued to the correct specification, and more importantly if they are not
torqued evenly, the "hot" rotors will be more prone to warping.
--Frank
"Jack Dannenberg" <cad...@worldnet.att.net> wrote in message
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