On Tue, 7 Aug 2018 04:25:26 -0000 (UTC), Arlen Holder
wrote:

On 6 Aug 2018 20:27:12 GMT, Clare Snyder wrote:

Lateral runnout caused by thermal release of stress IS warpage.

If the damned thing runs true untill it gets hot, then has runout
without thickness variation, it HAS WARPED.

Let's give up on this topic.
The same thing that is happening now, happened before.

It happens every time we discuss this topic.

People invariably "google" for "warp" and without comprehending the
reference, they throw whatever reference they find at me, as if I'm too
stupid to comprehend what it actually says.

Then, when I prove what the reference says, they change their definition of
"warp" because they feel that I chastised them and they don't like that.

So I'm sorry that the paper you provided doesn't say a single thing about
rotor warp. I really am sorry. I wish it did. But it just doesn't.

That's a fact.

Let's give up on this topic if the only way we can have an adult discussion
is that we have to use two different definitions of warp, where one
definition means anything you want it to mean, and where the other
definition is what all the references I quoted explain it to mean.
http://www.brakeandfrontend.com/warped-rotors-myth/

They missed the ONE thing that can cause lateral runout of a rotor -
warpage due to poor manufacturing whick allows casting stresses to be
released after machining - sometimes immediately, and sometimes after
they have been heat cycled. No extreme heat required, and NOTHING a
driver can do to prevent it. In the case of those that release the
stress after heat cycling, nothing a tech can do about it either -
other than machine it true -(once the stresses are ALL relieved, it
will not warp any further) after the fact.

When the stress comes out "in the box" or "on the shelf" machining the
rotor before installing has a 50/50 chance of solving the problem. The
rotor MAY be stable, or it may release more stress when heat cycled.

We had many cases of both at Toyota in the early to mid 80's. It was a
production problem which was eventually solved - and was only evident
on replacement rotors.

I had the same problems with the "economy" rotors from UAP (now NAPA)
- and it was on integrated front rotors (cast with hub) which
elimiunated ANY chance of it being an installation problem

I think 50 years experience actually diagnosing and repairing the
problems - and troubleshooting the issue for Toyota Canada beats your
"book learnin'" and cites from "automotive writers" - many of whom
couldn't tropubleshoot their way out of a wet paper bag if it was open
at both ends./
http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

Now you are believing the "marketing BS" from the
manufacturers/supplying who are saying the brake puilsation problems
are NEVER their fault - blame it on the mechanic or the driver.
Thought you didn't believe "marketing BS"
https://oppositelock.kinja.com/brake-myths-what-to-expect-when-youre-expecting-to-st-1688020147

Here's just one quote from that last reference:
"They¢re not warped and they never were warped."

ANd I say, in many cases they are right - but saying there is no such
thing as a warped rotor is total BS.
And the guy writing this last article could just as well be you. He's
no professional mechanic, and no materials engineer,

I won't respond further unless someone provides a reference that backs up
their point of view, as I've already provided plenty of references from
where I obtained my "book knowledge" that everyone seems to hate.

The references you have quoted are NOT scientific reviews - they have
no more (and generally less) veracity than the cite I provided for
you (which, by the way WAS - TOTALLY on topic.

I don't mind a good healthy technical discussion, but I have no interest in
redefining what "warp" means when it's already very well defined in
technical terms.


Give me that definition. I've given you what I accept as the
definition of warpage in this case - thermally induced lateral runout
without thickness variation, caused by the release of cast-in stresses
in the rotor.
If someone provides a paper that supports their viewpoint, I'll read it and
comment upon it - but otherwise - we're just spinning our wheels if we have
to change the definition of warp to prove that rotors do it in street use.

I apologize if I drop off (unless a reference is provided).


You can forget about any more help from me. Bye Bye