What are some car-repair jobs you always wished you could do but have never done?

On Mon, 6 Nov 2017 14:59:13 +1100, Xeno >
wrote:

>On 6/11/2017 2:24 PM, wrote:
>> On Mon, 6 Nov 2017 10:40:25 +1100, Xeno >
>> wrote:
>>
>>> On 6/11/2017 6:05 AM, Frank wrote:
>>>> On 11/4/2017 4:13 PM, wrote:
>>>>> On Sat, 4 Nov 2017 18:17:09 +0000 (UTC), RS Wood >
>>>>> wrote:
>>>>>
>>>>>> rickman wrote:
>>>>>>
>>>>>>> Same here.* Any car of mine that needed an engine wasn't worth
>>>>>>> putting an
>>>>>>> engine in.* Older cars were not made to last and that was true for
>>>>>>> every
>>>>>>> part of that car.* Even things like seats and headliners were shot
>>>>>>> by the
>>>>>>> time the engine was shot.* My current truck has 240,000 miles on it
>>>>>>> and the
>>>>>>> engine is one of a number of parts that shows nearly no sign of going
>>>>>>> anytime soon.* The parts that have been repaired often were not
>>>>>>> repaired
>>>>>>> right so some have needed repairing more than once, but otherwise
>>>>>>> the truck
>>>>>>> is very sound.
>>>>>>
>>>>>> You make a good point which I don't know the answer to.
>>>>>>
>>>>>> In my kid days, plastic toys did not exist (transistor radios didn't
>>>>>> exist
>>>>>> either), so our Tonka toys were rubber wheels and steel bodies.
>>>>>>
>>>>>> Nowadays, if you leave a kid's toy car outside, the sun alone will
>>>>>> destroy
>>>>>> it within a year or two.
>>>>>>
>>>>>> So they certainly don't build *some stuff* the way they used to.
>>>>>>
>>>>>> However ... cars *seem* to be different. Are they?
>>>>>>
>>>>>> My Chrysler's and Dodges days (in the olden days, we had brand loyalties
>>>>>> that sprang from the brand loyalties of our fathers) showed me that a
>>>>>> tuneup was needed every year, bias-ply tires lasted something like 20K
>>>>>> miles, and, as you said, the interior was shot by the time the engine
>>>>>> went.
>>>>>>
>>>>>> And that was in the days before plastic bumpers and plastic headlights
>>>>>> (they were real glass bulbs in those days).
>>>>>>
>>>>>> But yet, it seems to me, cars last forever now.
>>>>>> In those days, 100K miles was a lot.
>>>>>> Now, it seems, 200K miles is approaching a lot.
>>>>>>
>>>>>> Do they really make cars better but nothing else is better?
>>>>>> How can that be?
>>>>> ** They sure make cars a lot better -* experience and technology have
>>>>> made a lot of difference. ( Remember, in 1959, the automobile, as an
>>>>> object, was not as old as a 1959 car is today!!!!
>>>>>
>>>>> The reason just about anything else you buy today is NOT better is
>>>>> everyone wants it CHEAPER and expects to upgrade long before anything
>>>>> with any QUALITY would require replacement. Everything is changing SO
>>>>> FAST.
>>>>>
>>>>> * Most people want to buy the latest and greatest even before today's
>>>>> JUNK is worn out.
>>>>>
>>>>
>>>> I've heard that the younger crowd trades in cars because the electronics
>>>> are outdated, not the mechanical parts.
>>>>
>>>> Lot of us keep a car until repair cost exceeds book value.
>>>
>>> I trade my cars in when I'm sick of them.
>>
>>
>>
>> I get rid of mine when they finally **** me off once too often.
>> Usually after 10 years or so - and I buy them 5 to 10 years old.
>> Sometimes significantly older.
>>
>> When I get sick of fixing them, or something comes up that I decide
>> not to fix, it's adios amigo!!
>>
>I buy new and when anything more than tyres or brake pads is looming,
>it's bye bye. I'll work on other people's cars but I expect my own to be
>reliable and trouble free. When they are in excess of 150k kilometres,
>they are, as far as I am concerned, on their last legs.
I (generally) buy then at roughly 100000klm and drive them another
100 or so - generally with VERY little repairs and problems.The
current one was over 10 years old with 54000 KM - now up to 112000 and
I plan on keeping it another year or two. My wife would like a newer
car. Likely won't end up putting it over 200,000km - possibly not
over 150,000.

I bought my truck at 307000km and 16 years of age. 354000km on it
now, with only very minor issues. Still original rear brakes and just
about everything else. 47000km in 5 years - so it's not heavily used
and I hope to keep it going at least another 5 years.

My cars have always been reliable and virtually trouble free because I
stay ahead of them.

On 6/11/2017 5:35 PM, RS Wood wrote:
> Xeno wrote:
>
>>> That's not the measure of warp.
>>> Warp is measured on a flat bench.
>>> Just like head warp is measured.
>>
>> Or with a dial indicator - on both sides - for comparison.
>
> You *can* measure warp with a dial indicator if you control the centerline
> precisely, but nobody sane would do it that way.
>
> I'm only speaking logic. If you have a head that you need to know if it's
> warped, would you use
> a. a dial gauge or
> b. a flat benchtop with a feeler gauge?
>
> Pick one.
>
>> Use to check for warp every time.
>
> With a dial gauge?
> Or a flat bench and feeler gauge?
>
> I'm not saying it's hard to check warp (heck, people do it for heads all
> the time I suppose). I'm just saying that warp doesn't happen for the most
> part in street cars (I already have a half dozen references) and yet
> *every* idiot out there *thinks* his rotors warped.

Warped rotors will cause steering shimmy but not brake pumping. I
haven't seen many but I have seen some.
>
> Every time I asked anyone to prove it, they *said* all sorts of bull****,
> but they can't even tell me *how* they'd prove it. If they use a dial
> gauge, for example, while the rotor is on the vehicle for example, then I
> have to wonder how to respond because that just proves my point.
>
> Nobody who ever said their street rotors warped ever supplied proof.
> They all are bull**** artists.
>
>>>
>>> If they haven't measured it, it's not happening.
>>> And nobody measures it.
>>> So it didn't happen.
>>
>> Some do. I did. I also taught apprentices to measure for it.
>
> Measuring it is trivial if you have a bench and a feeler gauge.
>
> But show me a single picture on the entire Internet that shows someone
> measuring a street rotor for warp.
>
> Just one.
>
> Now show me the bull**** of someone saying they measure warp all the time.
> (HINT: We don't enough space on the Internet for the bull**** references.)
>
> There has never been a topic more filled with bull**** than rotor warp, and
> all the "experts" who claim they measure it and yet can't show a single
> picture of anyone on the planet doing that (not themselves either) for a
> street rotor.
>
>>> It "could" happen. But it doesn't (on street cars).
>>> The problem is the temperature never gets hot enough.
>>
>> It can under specific circumstances. See it most often on autos in very
>> hilly country.
>
> I give up.
>


--

Xeno

On Mon, 6 Nov 2017 15:03:55 +1100, Xeno >
wrote:

>On 6/11/2017 2:28 PM, wrote:
>> On Sun, 05 Nov 2017 19:58:14 -0500, "Steve W." >
>> wrote:
>>
>>> Xeno wrote:
>>>> On 6/11/2017 9:13 AM, wrote:
>>>>> On Sun, 5 Nov 2017 19:56:38 +1100, Xeno >
>>>>> wrote:
>>>>>
>>>>>> On 5/11/2017 3:15 PM, rbowman wrote:
>>>>>>> On 11/4/2017 9:32 PM, RS Wood wrote:
>>>>>>>> We were talking about timing belts inside car engines.
>>>>>>>>
>>>>>>>> The problem with timing belts on some engines is when they break, the
>>>>>>>> pistons can contact the valves, which is the dumbest bit of engineering I
>>>>>>>> have ever seen in my life.
>>>>>>> A belt is a belt. The point I was trying to make, albeit awkwardly, was
>>>>>>> visual inspection of the belt tells you nothing in most cases. You
>>>>>>> replace the thing after N miles based on the mean time to failure. If
>>>>>>> you have a timing belt that fails before that and an interference engine
>>>>>>> you can plan on replacing valves too. There are many things on an
>>>>>>> automobile that give you hints they should be replaced; timing belts
>>>>>>> just break.
>>>>>>>
>>>>>>> Timing chains used to be less dependable but the newer ones are greatly
>>>>>>> improved. I'm happy my Toyota has a chain. I haven't researched it but I
>>>>>>> do believe some manufacturers are going back to chains. Belts are
>>>>>>> cheaper but ****ed off customers aren't.
>>>>>> I have Toyotas precisely because they have a chain.
>>>>> Some do, some don't. (perhaps today they all do - not sure)
>>>>>
>>>> The ones I buy sure do! ;-)
>>>>
>>>
>>> Chains don't mean a lot when they drop them down to bicycle sizes with
>>> small pins. Things stretch like cheap rope.
>> Ever get involved with the two-chain 2.6 Chrysler Mitso****ty "hemi"
>> 4? About 6 feet of chain that stretched like a cheap underwear
>> elastic.
>>
>The go with any Mitsubishi timing chain system was to use *only*
>Mitsubishi genuine spares. None of the aftermarket crap was up to spec.
The oem stuff was crap too - and the biggest problem was Chtysler
didn't encourage people to change oil on the "extreme" schedule.
Changing the oil often with good oil extended the lifespan
significantly - but they were still trouble with a capital T.

Can't sell a Mits around here - even with their extreme warranty
every dealership around here has failed.

On 6/11/2017 5:52 PM, wrote:
> On Mon, 6 Nov 2017 14:50:30 +1100, Xeno >
> wrote:
>
>> On 6/11/2017 1:10 PM, wrote:
>>> On Sun, 5 Nov 2017 14:23:33 +0000 (UTC), RS Wood >
>>> wrote:
>>>
>>>> Xeno wrote:
>>>>
>>>>> GDI makes it almost an order of magnitude better
>>>>>> again.
>>>>>>
>>>>> Bzzztt. GDI has brought the scourge of carbon buildup back.
>>>>
>>>> Googling for what you mean by "GDI"...
>>>> <https://en.wikipedia.org/wiki/Gasoline_direct_injection>
>>>>
>>>> Pros and cons of gasoline direct injection...
>>>> <https://www.consumerreports.org/cro/news/2015/02/pros-and-cons-of-direct-injection-engines/index.htm>
>>>>
>>>> What's so great about gasoline direct injection anyway?
>>>> <https://www.cnet.com/roadshow/news/whats-so-great-about-direct-injection-abcs-of-car-tech/>
>>> The biggest advantage is the fuel is injected after initial
>>> compression, just before the spark - so the fuel is not "dwelling" in
>>> the combustion chamber under high heat and pressure, dissassociating
>>> and causing detonation. Can run much higher compression ratio on
>>> regular gas.
>>>
>> I suggest you read up on the topic. You can have stratified charge and
>> homogeneous charge in the same engine and these are the two different
>> strategies employed. Typically, in the higher load range the charge is
>> homogeneous in composition and the fuel is introduced into the
>> combustion chamber during the intake stroke. Under part load conditions
>> the engine uses charge stratification with the throttle valve fully open
>> and fuel is injected during the compression stroke.
> Detonation is generally not an issue at higher speed, so the
> stratified charge provides the advantage I ststed. Under full throttle
> at speed homogenous charge is not a problem.
>
It is the stratified charge that *removes* the possibility of
detonation. You can only generally get detonation with homogeneous charge.

--

Xeno

On 6/11/2017 5:53 PM, wrote:
> On Mon, 6 Nov 2017 14:51:59 +1100, Xeno >
> wrote:
>
>> On 6/11/2017 1:16 PM, wrote:
>>> On Sun, 5 Nov 2017 14:36:18 +0000 (UTC), RS Wood >
>>> wrote:
>>>
>>>> Xeno wrote:
>>>>
>>>>>> If toe is last, then unloading, adjusting, reloading makes more sense.
>>>>>>
>>>>> Toe is last. Adjustments to camber will alter toe. Adjustments to toe
>>>>> will not alter camber.
>>>>
>>>> Thanks. The way I'll remember it is Caster -> Camber -> Toe.
>>> Caster and camber are pretty well inter-related - changing one
>>> changes the other on most non-strut suspensions. Struts are a whole
>>> lot simpler.
>>>
>> Changing camber on a strut still changes toe.
> I didn't say it didn't. camber has a lot less effect on camber, and
> vice versa on a strut system than on a double wishbone system
>
That depends entirely on *where* you adjust that camber on the strut.

--

Xeno

On Mon, 6 Nov 2017 15:16:20 +1100, Xeno >
wrote:

>On 5/11/2017 8:19 AM, RS Wood wrote:
>> wrote:
>>
>>> Oh? used to be the rings and bearings, oil pump, lifters, and half
>>> the other moving parts in an engine required replacement within 60,000
>>> miles.
>>
>> I hear you that engines used to last only about 100K miles in those days,
>> but is that true.
>>
>> Are engines really far more reliable today?
>> Why?
>>
>> Is it because they're mostly Japanese?
>>
>>> And the fuel and ignition system parts in less than half that.
>>
>> I do agree that PCV valves and condensers and points and carbs required
>> maintenance basically yearly or every two years at the longest.
>>
>> Now, they're "almost" lifetime parts because they don't exist.
>
>The fuel system *still exists*. It just no longer looks like a carburetor.
>>
>>> Even timing CHAINS and GEARS often required replacement in roughly
>>> that time frame. I replaced LOTS of GM timing sprockets long before
>>> 60,000 miles - and that was a lot more work than replacing a timing
>>> belt.
>>
>> I'll agree with you that engines seem more reliable today than in
>> yesteryear.
>>
>> But why?
>
>Technology, pure and simple. And competition from OS makes.
>
>> What's the magic that makes a 150K-mile engine into a 300K-mile engine?
>>
>>> The timing chains on Mitsubishi (Chrysler) 2.6 engines seldom made
>>> 100,000 km (60,000 miles) if you followed the "normal" oil change
>>> schedule - and they were a LOT of work to change.
>
>They were underrated for the task. It's something that immediately came
>to my notice the first time I did a timing chain change on one.
>>

The problems they had with lubrication to the balance shafts didn't
help the bicycle chain they had driving them and the oil pump


>> That's bad.
>> I have never replaced a timing belt or a timing chain.
>> And I've gone well over 150K miles on cars with chains.
>
>A decently rated timing chain should be good for 200k miles at the
>least. That would see most engines out.
>>
>>> They are a LOT easier to access than they used to be on many
>>> engines. Transverse engines make EVERYTHING harder to change - even
>>> on an old Mini.
>>
>> I never had a FWD car in my life.
>> Nor a 4WD.
>
>I've had all sorts. I prefer FWD.
>>
>> Luckily, 2WD RWD cars spread out the "stuff" in manageable ways.
>>
>>> There are a lot of engines that I can change a timing belt on in less
>>> than 2 hours - even on my driveway.
>>
>> I don't even do an oil change in 2 hours. I take my sweet time.
>>
>> I think for a home mechanic, time only matters when the car is still on
>> blocks on Monday morning when you have to get to work (if you still work).
>>
>> Otherwise, time isn't the issue.
>>
>I consider my *time* as being valuable and I have many better things to
>do with it than work on servicing my own car.
I actually enjoy doing some of it - been 26 or 27 years since I did
it for a living - in my retirement as long as I have place to work, I
don't mind.

On Mon, 6 Nov 2017 04:48:28 +0000 (UTC), RS Wood >
wrote:

wrote:
>
>> Some of the best rotors out there are Chinese - but also some of the
>> worst. Consistency is the problem
>
>I can't argue but my point is that I've heard everything.
>The problem is that the advice has to be both logical and actionable.
>
>Saying "buy only Brembo or Meyle" is actionable, but not logical.
>Saying "don't buy Chinese crap" is logical but not actionable.
>
>For advice to be useful, it has to be both actionable and logical.
>I've never heard that in rotors other than buy solid and don't buy
>drilled/slotted rotors.
>
>Other than that, there's no way for a person to tell if one rotor is gonna
>be better than another.
>
>Hence pragmatically ... a rotor is a rotor is a rotor is a rotor.
>
>> In some instances (virtually never normal street use) grooved and
>> slotted rotors DO provide better braking. We are talking competition
>> use, where the rotors are glowing red hot half the time, and the pads
>> are off-gassing like crazy - where even 100% dry DOT4 brake fluid
>> boils in the calipers. Under those conditions, rotors can warp - and
>> even fracture (in Rallye use I've seen red hot rotors hit an icy
>> puddle and totally fracture)
>
>I'm never talking racing.
>They drive on bald tires for heaven's sake in racing!
>
>
>> Actually, on SOME cases you can. Look at the consistancy of the fins
>> in the rotors, and the even-ness of the thickness of the braking
>> surfaces on both sides of the fins.
>
>I'm not gonna disagree that we all can see the mark of good quality on some
>things when we have two to compare in our hand, but it's too late if you
>order on the net.

And only a total fool buys everything on the net. I can generally buy
off the shelf for close to the same price, with no hassle returns and
I get to see-feel EXACTLY what I'm buying.
>
>>>How are you gonna know the metallurgy?
>>
>> You don't - that's the hard part - but when you are in the business
>> you get to know which suppliers stand up, and which don't. If you
>> know the suppliers well, they will tell you which ones they have
>> trouble with, and which ones they don't.
>
>Yup. I have nothing against good suppliers. I use Brembo and Meyle but if
>someone else gave me a rotor at a better price, I'd consider them too.

Can't even BUY Brembo for my daughter's car.
>
>> And some rotors DO WARP. Not many - but I've had at least a bushel
>> basket full of genuinely warped rotors in my 25 year carreer. Most
>> "warped" rotors are not warped - but some are. Some DRASTICALLY - to
>> the point the caliper moves visibly when the wheel is turned - and if
>> the sliders stick the pedal jumps and the steering wheel twitches.
>
>That's not the measure of warp.
>Warp is measured on a flat bench.
>Just like head warp is measured.

Not in the real world. On a large percentage of rotors doing it your
way is totally impossible. And my way (the industry standard) I can
measure warpage/runout ON THE CAR and know if it's a problem before
taking ANYTHING apart beyond moving the rim.
>
>> More often than not though, they are either pitted or have deposit
>> buildup, ot they have "hard spots" due to metalurgical inclusions
>
>The only person who says their rotors warped that I will ever trust is one
>who measured the warp just like you'd measure head warp.
>
>If they haven't measured it, it's not happening.
>And nobody measures it.
>So it didn't happen.
>
>It "could" happen. But it doesn't (on street cars).
>The problem is the temperature never gets hot enough.
>
>Now they can be "warped" from the factory; but that's different (and rare).
>
>> Wrong tool. The one I'm talking about has tabs that fit into the
>> notches on the piston face to "thread" it in as you squeese. Can
>> sometimes get away with the $17 "cube" but the kit you KNOW is going
>> to work starts at about $35 for one of questionable quality, and goes
>> up very quickly from there (and IT won't turn back Mazda rear calipers
>> - they use a different system
>
>I think we're talking about two different kinds of disc brake systems.
>I had the Nissan 300Z which had the rear disc also as the rear parking
>brake, but my bimmer has the rear disc and a separate rear parking brake.

Really crappy system - sorry.


I've worked on everything from a moskovitch to a Rolls, with Jags,
Rovers, Toyotas, Fiats, Ladas, VWs, Nissans as well as just about
every North American brand
>
>The piston arrangement is different as is the way to retract them.
>
>You don't *twist* pistons in disc brakes that I own that don't have the
>parking brake as part of the disc brake itself.

I'm talking in general - not the limited vehicles of your experience.
>
>At least I don't.
>
>
>>>Never once in my life have I found a single person who has *measured* the
>>>warp.
>>
>> I have. many times.
>How?
>
>>>You know why?
>>>They don't even know *how* to measure rotor warp.
>>>They don't have the tools to measure rotor warp
>> A somple dial indicator tells the tale
>
>Nope.
>How you gonna tell runut from warp with a dial gauge?
\Measure in more than 2 places -
>
>> - and sometimes one side is
>> straight, and the other side is not - parallelism warpage - where some
>> fins collapse and one side of the rotor "caves in" - 1 inch thick on
>> one "side" of the rotor, and .875 or something like that diametrically
>> across the rotor. - and sometimes virtually deead flat on both
>> surfaces - other times with about hald paralel and the other half
>> "sloped"
>
>Now you're straining credularity.

No I'm not. Seen it many times
>
>>>(Hint: It requires a flat benchtop and feeler gauges and it's not hard -
>>>but they don't know that because they didn't measure a single thing.)
>>
>> That won't necessarilly tell you anything. The only way to KNOW is to
>> use a dial indicator properly.
>
>How you gonna tell runut from warp with a dial gauge?

Watch the needle move.
>
>> And that is where YOU are WRONG.
>> Many technicians measure brake rotors virtually every day of their
>> working lives.
>
>On the entire freaking Internet, find *one* picture (just one) of a
>technician actually properly measuring brake rotor *warp*.

The internet doesn't show EVERYTHING. What you know comes from the
web. What I know comes from tears in the trade (including teaching the
trade)
>
>Just find a *single* picture please. Just one.
>On the entire freakin' Internet.
>
>Find one.
>
>> Dealerships were then REQUIRED to buy an "on-the-car lathe" to true
>> up rotors.
>
>That's not warp.
>Nothing on this planet is going to fix warp.
>There's not enough metal to remove.

That is totally dependent on how much warp. And what, other than
"warp" will cause a rotor to develop "runout" if it is totally true
when installed.
>
>> A wize man learns from the mistakes of others - a fool never learns
>> because he "never makes mistakes"
>
>Which is why I wish I had done these half-dozen jobs:
>1. Alignment
>2. Transmission
>3. Engine
>4. Tires
>5. paint

Ond I've dome them all at least once.
>
>> Yes - you are right to the extent that MOST "warped rotors" are not.
>> But you are absolutely WRONG when you say they never warp in
>> street/highway use and anyone who says they have had a warped rotor is
>> lying and hasn't measured the rotor to prove it.
>
>I never once said "never" but "almost never" which is different, and we're
>only talking street, and I have references that back up everything I say
>whereas you provided zero references for what you said.

You have references I have experience.
>
>I'm not here to argue opinions.
>I only argue using logic.

Reality defies logic.
>
>Just read the references I provided and then provide some references that
>back up your point of view.
>
>The "Warped" Brake Disc and Other Myths of the Braking System
><http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths>
>
>The 'Warped Rotor' Myth
><http://www.10w40.com/features/maintenance/the-warped-rotor-myth>
>
>Warped Brake Rotors - Vibrating Reality or Internet Myth?
><https://blog.fcpeuro.com/warped-brake-rotors-vibrating-reality-or-internet-myth>
>
>Stop the +IBg-Warped+IBk- Rotors Myth and Service Brakes the Right Way
><http://www.brakeandfrontend.com/warped-rotors-myth/>
>
>Raybestos Brake Tech School, Part One: Rotors Don't Warp
><http://www.hendonpub.com/resources/article_archive/results/details?id87>
Only the stop-tech article is written by a pro (Can't open the
raybestos link so it's useless)

The rest could be written by you - same level of cred. They are
written by enthusiasts who have read articles.

They are correct in most of what they say - but real warpage DOES
exist, because not all rotors are properly manufactured and stress
relieved and heat treated - like the problem Toyota had in the early
'80s, and many of the "crap" rotors in the aftermarket - as I have
explained before. In the "ideal world" they would never warp. Also,
not all rotors spend their life in "normal" conditions - other
problems in the braking system, or abuse, can cause a lot more heat
than normal driving - which is why the accurate stement is:

"Under normal operating conditions, properly manufactured and
installed brake rotors very seldom actually WARP. Poor quality rotors
can warp, as can rotors that are severely overheated due to abuse or
certain braking system falures. When you experience brake pulsation,
actual brake rotor warpage is UNLIKELY to be the problem - but
stranger things HAVE happened. Uneven friction material transfer due
to either poor intial bedding of the pads or improper use of the
brakes is much more likely, and some brake pads are more prone to
causing these issues due to their composition. In areas where winters
are more severe and salt is used on the roads some pad compostions are
more likely to cause problems - particularly the hard-spotting and
pitting of rotors due to localized overheating caused by uneven
friction material transfer. Many brake problems tend to be regional in
nature for this reason. Rustout of cooling fins of a rotor, for
instance, would be unheard-of in arizona or alabama, but fairly common
in the northeat and the "rust belt".


NEVER say never and ALWAYS avoid always.

On Mon, 6 Nov 2017 04:48:30 +0000 (UTC), RS Wood >
wrote:

>Xeno wrote:
>
>> Any scoring on a rotor will fail it. As you say, there might be less
>> than 50% of the pad surface in contact with the rotor surface. No way
>> will that bed in properly. You will get localised overheating both on
>> the pad and on the rotor.
>
>I'm not gonna argue vehemently because, in practice, while I've seen those
>"wavy" rotors too, my rotors tend to be smooth so I don't deal with
>"scoring".
>
>However, anyone who says "any scoring of rotors will fail it" has NOT looke
>up the manufacturer's spec for scoring tests.
>
>I have. Long ago.
>
>The result was shockingly huge.
>
>I don't remember the actual number but I remember being shocked at how huge
>it is. Something like tens of thousanths of an inch in width huge.
>
>We're talking Grand Canyon in rotors.
>
>I may be wrong but if someone says "any" scoring, that's just preposterous.
>Let's see a manufacturer's spec for anyone who says that.
>
>Sorry. It's just not logical that 'any' scoring fails a rotor.
ANY mechanical damage fails the rotor on DOT test. Some smoth wear is
allowed - but you NEVER install new pads on rotors that have an uneven
friction surface because it is virtually impossible to properly bed
the new pads to the uneven rotor withot localized overheating

At the price of rotors today even on your Bimmer, it just is not
worth it. The pads cost more than the rotors on MOST vehicles today.
No reputable shop will do it because comebacks are expensive - and
real mechanics KNOW the comebacks will happen if they do something
stupid like installing new pads on badly worn rotors.

On Mon, 6 Nov 2017 04:48:32 +0000 (UTC), RS Wood >
wrote:

>The Real Bev wrote:
>
>>> If the vibration decreases, or markedly changes character, or even goes
>>> away, then how could it possibly have been rotor warp in the first place?
>>
>> I wish I could remember when I stopped noticing it. I might have done a
>> hard stop to test whether the seat belts were still working properly...
>
>It's impossible to diagnose brake-related judder/shudder/vibration on the
>Internet - but - most of the time - the cause is the simplest most obvious
>reason.
>
>You drive hard on the highway and then stop hard at the bottom of an exit
>ramp at a light where you sit there with your foot on the brake for a
>period of time.
>
>Guess what happens?
>
>For a hard-to-understand reason, the teeeniest tiniest pad imprint tends to
>grow over time. I don't really understand why, but it does. It gets almost
>imeasurably larger over time, until you finally feel it while braking at
>speed.
Not hard to understand at all. Uneven friction causes uneven heating,
and localized overheating causes enhanced friction material transfer -
which just cascades.
>
>What's the solution?
>Simple.
>
>SHORT TERM: Scrape that deposit off.

Short term? Gently re-bed the pads. Works high percentage of the
time if you don't allow it to get progressively worse to the point you
get cabide inclusions in the rotors.

>LONG TERM: Change your braking habits.
>
>>> Q: Is a $50K rolex watch a better watch than a $30 Timex watch?
>>> A: The watch that keeps better time is the better watch.
>>
>> Ha. My $25 Casio atomic solar watch has been providing accurate time
>> since 2008 with no attention whatsoever. The beautiful 195x Omega
>> Seamaster is sitting in a box somewhere because it needed to be cleaned
>> every couple of years. Apparently the lubricant breaks down -- it
>> doesn't seem that dirt could get into a waterproof watch. I guess it
>> was accurate, I didn't have anything to check it against but the nice
>> lady on the phone who told me the time.
>
>I have a few Rolex watches (most received as gifts).
>They suck at keeping time.

The Rolex my dad bought when I was born (basic Tudor model - 1952)
has been rebuilt twice and still keeps extremely accurate time.

Also, ALL Rolex watches are made in Switzeraland - if it says Tolex
Japan it is NOT a Rolex (I have one of those)
>
>For brake pads, the thing you care about is friction, cold and hot.
>Nothing else is close in importance (although dusting is key for some).
>
>So pick your pads by what the OEM pads were and try to meet or exceed that.
>Most pads are around FF but every pad says what it is or it can't be sold
>in the USA.
>
>The (SAE J866a) charts are all over the net.
>Just look for 'brake pad friction ratings' or something like that.
>
>> I drive roughly 4K miles/year and front pads on other cars generally
>> were OK for 40K miles (rear shoes double that). ~20K now. I'll
>> remember this just as long as I can :-)
>
>Life is one thing but the *primary* factor in brake pads is friction.
>
>I buy $35 PBR pads with FF or GG friction ratings which last 30K miles or
>so and the dust isn't objectionable.
>
>So my factors a
>a. Friction rating (anything less than FF is worthless)
>b. Non-objectionable dust (the only way to know is to ask owners)
>c. Decent life (the only way to know is to ask owners)
>
>Friction Coefficient Identification System for Brake Linings
><http://standards.sae.org/j866_200204/>

On Mon, 6 Nov 2017 04:48:34 +0000 (UTC), RS Wood >
wrote:

wrote:
>
>>>Adjustable wrenches should be banned as a menace to society.
>> They are totally fine for some applications - but NOT bolts on a
>> car!!
>
>I was joking, but I still don't get why I see people use them all the time
>when they slip too much because they fit so badly and only on a few edges
>and they are huge compared to the right-sized box wrench so they don't fit
>in a car.
>
>I'm gonna start a "Save the bolts" non-profit political group to enact
>stringent adjustable-wrench control laws!
>
>One rounded bolt head is too many.
>
One skinned knuckle is one too many!!!