On 2022-05-12 5:45 p.m., Andy Burnelli wrote:
> AMuzi wrote:
>
>> If you're so certain about that why not offer to pay parts and service
>> charges for a warped brake rotor?
>
> If that's supposed to be a question, I readily admit I don't know what
> you're asking.
>
> Can you please rephrase the question so that I can understand what you're
> asking me to respond to?
>
> Thanks!

And he's not just suddenly playing dumb, folks!

On 12/5/2022 11:05 pm, sms wrote:
> On 5/11/2022 6:29 PM, Xeno wrote:
>> On 12/5/2022 6:01 am, Alan wrote:
>
>>> <https://www.youtube.com/watch?v=DiuwzN2mQuA&t=122s>
>>
>> Yep, done that, seen the warp, many, many times!
>>
>> I liked the way he did that final non-directional finish. I used to do
>> it the hard way, that looked easy in comparison.
>
> Good video
>
> Andy Burnelli/Arlen Holder/Dean Hoffman/Nil/Robin Goodfellow/more is
> wrong of course™.
>
> Those look like pretty thick rotors. The warping had to be pretty minor
> in order to machine them flat. Most of the rotors these days are too
> thin to machine and are just replaced as part of brake job.

Yeah, that's been the trend for quite some time now. Rotors are
considered as *disposable* as the pads themselves.
>
> There is one train of thought that turning sufficiently thick, flat,
> non-warped, rotors, is unnecessary and that after a short while the pads
> will break in to match the minor imperfections in the rotor, with just a
> little extra wear on the pads. "If your rotor surface is smooth there is

Indeed, I need to see a very overt issue before I would bother machining
rotors. If you don't feel the symptoms on a road test, measurements look
ok and the surfaces aren't gouged, I just fit pads, then do a bed in process

> generally no need to have them turned. If, however, you have warping, or
> rough spots they should be turned, or replaced if need be. This is
> easily detected if you have a solid, non-pulsing braking action when you
> press down on the pedal,"
> <https://www.carsdirect.com/car-repair/when-should-you-turn-brake-rotors>.

--
Xeno

Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)

On 13/5/2022 9:25 am, Alan wrote:
> On 2022-05-12 4:01 p.m., Andy Burnelli wrote:
>> sms wrote:
>>
>>> <https://www.carsdirect.com/car-repair/when-should-you-turn-brake-rotors>.
>>>
>>
>> People like Steve are no different than people who believe the earth
>> is flat.
>> Steve actually _believes_ what he writes.... and yet... And yet... and
>> yet... Steve doesn't even _read_ what the experts say about it.
>>
>> As a result, Steve will _never_ (ever!) find a reputable expert to
>> back up his
>> claims that the earth is, dammit, flat.
>>
>> But... he can _always_ find a salesperson selling bullshit to back him
>> up.
>> Which is what Steve did in this thread (and with his four URLs):
>> <https://www.cartalk.com/blogs/dear-car-talk/warped-brake-discs-are-bad-news>
>>
>> <https://brakeexperts.com/what-causes-brake-rotors-to-warp/>
>> <https://www.sandiegouniontribune.com/cars/click-and-clack/story/2019-05-02/warped-rotors-give-this-pony-the-shakes>
>>
>> <https://www.carsdirect.com/car-repair/when-should-you-turn-brake-rotors>.
>>
>>
>> Notice Steve can't find even a _single_ expert backing up his claims
>> that the earth is flat simply because he found people who said so.
>
> Empiricism trumps your bullshit, Arlen:
>
> 'In the past people here have said that rotors don't "warp". That
> shaking or shuddering during braking is caused by brake pad deposits.
> This is on my lathe right now. You can see the spots where the bit is
> not even touching the rotor. Definitely NOT pad deposits. The bits are
> missing the rotor on opposite sides like you would think it would if a
> rotor was warped. Thoughts?'
>
> <https://bobistheoilguy.com/forums/threads/warped-rotor-pics.309555/>

Yep, very familiar with that scenario. Been there, seen that, done that!

;-)

--
Xeno

Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)

Xeno wrote:

> Indeed, I need to see a very overt issue before I would bother machining
> rotors. If you don't feel the symptoms on a road test, measurements look
> ok and the surfaces aren't gouged, I just fit pads, then do a bed in process

Hi Xeno,
On _that_ topic alone, have you ever seen a typical rotor "gouge" spec?
I have.

That spec is often hard to find, but when found, it's shocking (to me).
For two reasons.

The first is that the spec allows _huge_ gouges (imho).
And the second is I've never seen a rotor _that_ gouged.

No big deal. I'd junk any rotor that doesn't meet spec w/o a second thought
since a rotor is a safety item that costs only about $15 to $35 per wheel.

While I'm not saying gouges can't happen, I've _never_ failed a rotor on
its gouge spec in my life (however I only replace my own rotors of course).

My question to you are the two above:
a. Have you seen how (seemingly) huge a gouge has to be to fail spec?
b. How often have _you_ seen a rotor gouged enough to fail that spec?

On 2022-05-13 10:21 a.m., Andy Burnelli wrote:
> Xeno wrote:
>
>> Indeed, I need to see a very overt issue before I would bother
>> machining rotors. If you don't feel the symptoms on a road test,
>> measurements look ok and the surfaces aren't gouged, I just fit pads,
>> then do a bed in process
>
> Hi Xeno,
> On _that_ topic alone, have you ever seen a typical rotor "gouge" spec?
> I have.

We can certainly see what you wanted to change the topic.

Xeno wrote:

> Yeah, that's been the trend for quite some time now. Rotors are
> considered as *disposable* as the pads themselves.

Hi Xeno,
(See the question in the bottom of the introductory explanation below.)

A _lot_ of morons (like Steve) "claim" to need to replace rotors with every
pad change, and even more morons opine that they simply replace rotors at
every second pad change, and even more morons than those prevalent types,
ask on the car forums the dumbest question possible, which is
Q: *How do you know when to replace your rotors?*

The reason all those three are the brain child of morons is that you
replace a rotor when it no longer meets the spec, and, as you note below,
the spec contains a few simple components, _all_ of which require tools.

Just as Dunning & Kruger wondered what made the bank robber think the lemon
juice would work, and just as I wonder what makes iKooks believe their
fabrications of functionality would work, I have wondered for years why
people ask the dumbest "what oil" type of questions on car forums.

Over the decades, I've realized the "what oil" questions and the when do I
replace rotors questions are born of the exact same "Steve" mentality.
1. They don't know the spec, and,
2. They don't own the tools to _measure_ to the spec.

It's really that simple, don't you think?
Q: When do you replace rotors?
A: When they no longer meet the spec.

Q: On rotors, how do you know when they no longer meet the spec?
A: You measure them.

Q: What tools do you need to measure rotors?
A: The most often missing tool is a dial gauge with a good sturdy mount.
The second most often missing tool is a simple one-inch mic.
The third most often missing tool is a gouge depth and width gauge.

The tool I don't yet own is the latter (as I've never needed it).
So I use a coin of the correct width but that's not the "right" tool.

Q: What tool do _you_ use to measure the depth and width of a gouge?
A: Xeno?

>> There is one train of thought that turning sufficiently thick, flat,
>> non-warped, rotors, is unnecessary and that after a short while the pads
>> will break in to match the minor imperfections in the rotor, with just a
>> little extra wear on the pads. "If your rotor surface is smooth there is

> Indeed, I need to see a very overt issue before I would bother machining
> rotors. If you don't feel the symptoms on a road test, measurements look
> ok and the surfaces aren't gouged, I just fit pads, then do a bed in process

Given rotors cost about what it costs to machine them (and, in my last
clutch replacement, flywheel machining was $60 while a brand new flywheel
was only about $80), I have never bothered to have _my_ rotors machined.

However, I've also never taken a car to a mechanic in my life for something
as trivial as a four wheel brake job, which is just about the easiest job
anyone can do at home if they have the most basic of the simplest of tools.

The bed in process is critical in terms of what people call 'warp' (which
is simply that the car does funny things, which I won't call 'shudder' or
'judder' or 'shimmy' or 'pulsations' since people call _everything_ "warp".

However, that bed in process takes an appreciable amount of time,
especially in areas like those where I live where the highway is nowhere
near, and it's jam packed during all hours of the day with traffic.

My question to you, Xeno, and to any others who get brakes done by the
professional mechanics, is this simple but very important question:

Q: Do professional mechanics take the car on a drive to do proper bedding?

On 2022-05-13 10:40 a.m., Andy Burnelli wrote:
> Xeno wrote:
>
>> Yeah, that's been the trend for quite some time now. Rotors are
>> considered as *disposable* as the pads themselves.

This text does not exist in the post to which you're replying, Arlen...

....so now you're just a liar.

On Fri, 13 May 2022 10:25:35 -0700, Alan wrote:

> On 2022-05-13 10:21 a.m., Andy Burnelli wrote:
>> Xeno wrote:
>>
>>> Indeed, I need to see a very overt issue before I would bother
>>> machining rotors. If you don't feel the symptoms on a road test,
>>> measurements look ok and the surfaces aren't gouged, I just fit pads,
>>> then do a bed in process
>>
>> Hi Xeno,
>> On _that_ topic alone, have you ever seen a typical rotor "gouge" spec?
>> I have.
>
> We can certainly see what you wanted to change the topic.

It shirly looks like he was replying to what Xeno said about surface
gouges.

On 2022-05-13 11:00 a.m., dan wrote:
> On Fri, 13 May 2022 10:25:35 -0700, Alan wrote:
>
>> On 2022-05-13 10:21 a.m., Andy Burnelli wrote:
>>> Xeno wrote:
>>>
>>>> Indeed, I need to see a very overt issue before I would bother
>>>> machining rotors. If you don't feel the symptoms on a road test,
>>>> measurements look ok and the surfaces aren't gouged, I just fit pads,
>>>> then do a bed in process
>>>
>>> Hi Xeno,
>>> On _that_ topic alone, have you ever seen a typical rotor "gouge" spec?
>>> I have.
>>
>> We can certainly see what you wanted to change the topic.
>
> It shirly looks like he was replying to what Xeno said about surface
> gouges.

And leaving out that the conversation was about rotors warping...

....without having the class to admit he was wrong.

On Fri, 13 May 2022 12:11:35 -0700, Alan wrote:

> And leaving out that the conversation was about rotors warping...

There's no law requiring repeating everything that was already said.
It's typical & normal & courteous to NOT repeat everything that was said.
Look it up.
Common netiquette is you only quote the few lines you're responding to.

Those who disagree are always the trolls who have their own agenda.

On 2022-05-13 4:57 p.m., dan wrote:
> On Fri, 13 May 2022 12:11:35 -0700, Alan wrote:
>
>
>> And leaving out that the conversation was about rotors warping...
>
> There's no law requiring repeating everything that was already said.

"Law"? Of course not.

> It's typical & normal & courteous to NOT repeat everything that was said.

Is it typical, normal, and courteous to repeatedly call someone a liar
(essentially)...

....and then when it shown that you are clearly wrong to move on without
apologizing?

> Look it up.
> Common netiquette is you only quote the few lines you're responding to.

Common etiquette says to acknowledge when you've been shown to be wrong.

>
> Those who disagree are always the trolls who have their own agenda.

I don't disagree.

But my problem was him snipping the lines.

On Fri, 13 May 2022 19:11:39 -0700, Alan wrote:

> But my problem was him snipping the lines.

You're nothing but a whiny troll.
Go away.

On 2022-05-13 7:27 p.m., dan wrote:
> On Fri, 13 May 2022 19:11:39 -0700, Alan wrote:
>
>
>> But my problem was him snipping the lines.
>
> You're nothing but a whiny troll.
> Go away.

Nah.

I think I'll stay.

:-)

In message <t5mah9$4ph$1@dont-email.me> Alan <nuh-uh@nope.com> wrote:
> On 2022-05-13 11:00 a.m., dan wrote:
>> On Fri, 13 May 2022 10:25:35 -0700, Alan wrote:
>>> We can certainly see what you wanted to change the topic.
>> It shirly looks like he was replying to what Xeno said about surface
>> gouges.

> And leaving out that the conversation was about rotors warping...

> ...without having the class to admit he was wrong.

Arleen is a lying sack of shit without the slightest hint of class.

Please, every time you're going to reply to him imagine that little
chubby he gets and think again. Do you really want to be responsible for
the only sexual stimulation that obese naked troglodyte gets in his
life? Please, think of that image first.

--
Polexia: Let's deflower the kid.

On 14/5/2022 3:21 am, Andy Burnelli wrote:
> Xeno wrote:
>
>> Indeed, I need to see a very overt issue before I would bother
>> machining rotors. If you don't feel the symptoms on a road test,
>> measurements look ok and the surfaces aren't gouged, I just fit pads,
>> then do a bed in process
>
> Hi Xeno,
> On _that_ topic alone, have you ever seen a typical rotor "gouge" spec?

Can't recall. I just looked at the rotor gouge and, if *I* considered it
too deep, into the bin it went. You have to realise that *any gouge*
reduces the surface area for braking so if it doesn't machine out, it
will take ages for the pads to fully bed, if at all, and will lead to
unbalanced braking if the gouges on each side of the car aren't balanced.

> I have.
> That spec is often hard to find, but when found, it's shocking (to me).
> For two reasons.
>
> The first is that the spec allows _huge_ gouges (imho).

I use my own judgement.

> And the second is I've never seen a rotor _that_ gouged.

I have seen terribly gouged rotors - and I've binned them.
>
> No big deal. I'd junk any rotor that doesn't meet spec w/o a second thought
> since a rotor is a safety item that costs only about $15 to $35 per wheel.

Pre-cisely!
>
> While I'm not saying gouges can't happen, I've _never_ failed a rotor on
> its gouge spec in my life (however I only replace my own rotors of course).
>
> My question to you are the two above:
> a. Have you seen how (seemingly) huge a gouge has to be to fail spec?

Again, I use my own judgement.

> b. How often have _you_ seen a rotor gouged enough to fail that spec?

I have had heaps of rotors, and drums, fail my judgemental spec.

--
Xeno

Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)

On 14/5/2022 3:40 am, Andy Burnelli wrote:
> Xeno wrote:
>
>> Yeah, that's been the trend for quite some time now. Rotors are
>> considered as *disposable* as the pads themselves.
>
> Hi Xeno,
> (See the question in the bottom of the introductory explanation below.)
>
> A _lot_ of morons (like Steve) "claim" to need to replace rotors with every
> pad change, and even more morons opine that they simply replace rotors at
> every second pad change, and even more morons than those prevalent types,
> ask on the car forums the dumbest question possible, which is Q: *How do
> you know when to replace your rotors?*

I have often seen discs worn beyond limits by the end of the second set
of pads. When to replace? When they don't clean up on a lathe, are
undersized, or I use my judgement to assess that gouges, etc may cause
bed-in and braking balance issues. After you've done a few hundred, you
soon get a feel for what works ok and what doesn't.
>
> The reason all those three are the brain child of morons is that you
> replace a rotor when it no longer meets the spec, and, as you note below,
> the spec contains a few simple components, _all_ of which require tools.

And, because I was working *in the trade*, and later teaching my trade
in a college, I always had access to the required tools.
>
> Just as Dunning & Kruger wondered what made the bank robber think the lemon
> juice would work, and just as I wonder what makes iKooks believe their
> fabrications of functionality would work, I have wondered for years why
> people ask the dumbest "what oil" type of questions on car forums.
>
> Over the decades, I've realized the "what oil" questions and the when do I
> replace rotors questions are born of the exact same "Steve" mentality.
> 1. They don't know the spec, and, 2. They don't own the tools to
> _measure_ to the spec.
>
> It's really that simple, don't you think?
> Q: When do you replace rotors?
> A: When they no longer meet the spec.
>
> Q: On rotors, how do you know when they no longer meet the spec?
> A: You measure them.
>
> Q: What tools do you need to measure rotors?
> A: The most often missing tool is a dial gauge with a good sturdy mount.
>    The second most often missing tool is a simple one-inch mic.

A one inch mic is *useless* if it is of the standard form. You *need* a
disc micrometer whereby the bottom of the disc surface can also be
measured as well as near the periphery. After all, one of the checks
required is a *taper measurement*.

>    The third most often missing tool is a gouge depth and width gauge.

Again, I use the disc mic for depth but, whilst in the trade, I used my
own judgement.
>
> The tool I don't yet own is the latter (as I've never needed it).
> So I use a coin of the correct width but that's not the "right" tool.
>
> Q: What tool do _you_ use to measure the depth and width of a gouge?
> A: Xeno?

The brake disc micrometer designed for the purpose of course. But, as I
said in another post, with gouges I use my own judgement.
>
>>> There is one train of thought that turning sufficiently thick, flat,
>>> non-warped, rotors, is unnecessary and that after a short while the
>>> pads will break in to match the minor imperfections in the rotor,
>>> with just a little extra wear on the pads. "If your rotor surface is
>>> smooth there is
>
>> Indeed, I need to see a very overt issue before I would bother
>> machining rotors. If you don't feel the symptoms on a road test,
>> measurements look ok and the surfaces aren't gouged, I just fit pads,
>> then do a bed in process
>
> Given rotors cost about what it costs to machine them (and, in my last
> clutch replacement, flywheel machining was $60 while a brand new flywheel
> was only about $80), I have never bothered to have _my_ rotors machined.

That is what happens nowadays. Back in the day, some rotors were
damnably expensive - especially those integral with the hub. You had no
choice but to maximise their lifespan whenever possible.
>
> However, I've also never taken a car to a mechanic in my life for something
> as trivial as a four wheel brake job, which is just about the easiest job
> anyone can do at home if they have the most basic of the simplest of tools.
>
> The bed in process is critical in terms of what people call 'warp' (which
> is simply that the car does funny things, which I won't call 'shudder' or
> 'judder' or 'shimmy' or 'pulsations' since people call _everything_ "warp".
>
> However, that bed in process takes an appreciable amount of time,
> especially in areas like those where I live where the highway is nowhere
> near, and it's jam packed during all hours of the day with traffic.
>
> My question to you, Xeno, and to any others who get brakes done by the
> professional mechanics, is this simple but very important question:
>
> Q: Do professional mechanics take the car on a drive to do proper bedding?

Short answer, yes. Well, I used to! Not only was I taught to do that, I
saw the need.

--
Xeno

Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)

Xeno wrote:

> But, as I
> said in another post, with gouges I use my own judgement.

Almost nobody knows the spec for gouges for any given rotor in my
experience, and, when the spec id finally found (if found), it's shocking
how _huge_ a gouge has to be to fail a rotor.

They're not really hard to measure though, simply because of the spec.

Those who have never seen the spec for gouges wouldn't know that.

Xeno wrote:

>> b. How often have _you_ seen a rotor gouged enough to fail that spec?
>
> I have had heaps of rotors, and drums, fail my judgemental spec.

I have only about a half dozen old rotors in my garage in a heap.
They're useful for weights, but I was hoping to find a use for them.

Lewis wrote:

> Arleen is a lying sack of shit without the slightest hint of class.
>
> Please, every time you're going to reply to him imagine that little
> chubby he gets and think again. Do you really want to be responsible for
> the only sexual stimulation that obese naked troglodyte gets in his
> life? Please, think of that image first.

Hehhehheh... Lewis _hates_ that he knows nothing about the topic.

On 14/5/2022 3:57 pm, Andy Burnelli wrote:
> Xeno wrote:
>
>>> b. How often have _you_ seen a rotor gouged enough to fail that spec?
>>
>> I have had heaps of rotors, and drums, fail my judgemental spec.
>
> I have only about a half dozen old rotors in my garage in a heap.
> They're useful for weights, but I was hoping to find a use for them.

Recycle them - scrap iron.

--
Xeno

Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)

On 2022-05-13 10:58 p.m., Andy Burnelli wrote:
> Lewis wrote:
>
>> Arleen is a lying sack of shit without the slightest hint of class.
>>
>> Please, every time you're going to reply to him imagine that little
>> chubby he gets and think again. Do you really want to be responsible for
>> the only sexual stimulation that obese naked troglodyte gets in his
>> life? Please, think of that image first.
>
> Hehhehheh... Lewis _hates_ that he knows nothing about the topic.

The irony.

On 5/13/2022 10:08 PM, Xeno wrote:

<snip>

> I have often seen discs worn beyond limits by the end of the second set
> of pads. When to replace? When they don't clean up on a lathe, are
> undersized, or I use my judgement to assess that gouges, etc may cause
> bed-in and braking balance issues. After you've done a few hundred, you
> soon get a feel for what works ok and what doesn't.

It depends on the vehicle and how thick the rotors are. I recall my
1970's to 1990's VWs that had very thick rotors. The late 1970's was the
time when disc brakes were becoming standard equipment even on
lower-priced cars. Those rotors could be resurfaced many times. It was
the pads, on that first VW, that were really too small and wore out quickly.

Unfortunately, in the effort to increase fuel economy, manufacturers
made rotors much thinner, and essentially disposable. You could get by
with replacing pads only, but you couldn't resurface the thin rotors,
there just wasn't enough metal (which is also the reason that they
warped so readily). When a car dealer's service department advertises
low prices for brake jobs and it includes "resurfacing rotors" you can
be pretty, sure that if it's a recent vintage car, that you'll get a
call insisting that the rotors need to be replaced at an extra $150 or so.

Andy Burnelli can learn about rotors and resurfacing here:
<https://www.repairsmith.com/i/blog/resurface-rotors/>

sms wrote:

> Andy Burnelli can learn about rotors and resurfacing here:

Steve,
You make something as simple as a spec into some kind of voodoo magic.

Every statement from you shows you have _never_ done a proper brake job in
your entire life, which is why you posted total bullshit about rotor warp.

Rotors don't warp.
They can't.

You need in excess of 2300 degrees F (brake fluid boils at 1/4 that temp!).
The brake system would be marshmallows by the time rotors got hot enough.

The _only_ way to know when to fail a rotor is when it fails the spec.
Period.

And the best way to tell if it fails the spec is either to _see_ cracks in
the rotor (or some other _major_ failure indicator), or, to measure it.

Only you and Alan Baker could (or would) possibly claim otherwise.

Xeno wrote:

>> I have only about a half dozen old rotors in my garage in a heap.
>> They're useful for weights, but I was hoping to find a use for them.
>
> Recycle them - scrap iron.

Hi Xeno,

I assess you as the most knowledgeable here (certainly you have more
experience than I do); however I will point out you dodged both issues.

1. You dodged the issue that brake rotors can't possibly warp
simply because the 2300 degrees needed would make the rest
of the components disintegrate (e.g., brake fluid boils at
less than 1/4 of that temperature - and you know this).

2. You dodged the issue that you fail a brake rotor on one
condition and one condition only - which is if it no longer
meets the spec.

On the specific spec of gouge depth and width, I also noticed you dodged
that, which tells me you've never looked at a spec sheet in your life.

Don't feel badly about that.
Almost nobody does.

Everyone _says_ they do.
But they lie.

Like you did.
And that's OK.

I'm not _expecting_ anyone here to know what I know about brakes.
Not even you, even as I defer to your mass of experience over mine.

I just tell it like it is.
Most people bullshit.

On 2022-05-14 6:30 a.m., Andy Burnelli wrote:
> Xeno wrote:
>
>>> I have only about a half dozen old rotors in my garage in a heap.
>>> They're useful for weights, but I was hoping to find a use for them.
>>
>> Recycle them - scrap iron.
>
> Hi Xeno,
>
> I assess you as the most knowledgeable here (certainly you have more
> experience than I do); however I will point out you dodged both issues.
>
> 1. You dodged the issue that brake rotors can't possibly warp
>   simply because the 2300 degrees needed would make the rest
>   of the components disintegrate (e.g., brake fluid boils at
>   less than 1/4 of that temperature - and you know this).
>

He didn't dodge the issue and neither did I.

He stated from personal experience that he had seen warped rotors and I
presented video that conclusively showed warped rotors.