| Vic Smith <thismailautodeleted@comcast.net>: Nov 06 02:36AM -0800 > Only the stop-tech article is written by a pro (Can't open the >raybestos link so it's useless) That "pro" says to replace brake fluid once a year. I wonder how many people do that. I never replace brake fluid unless I've got the system open. |
| clare@snyder.on.ca: Nov 06 04:39AM -0500 On Mon, 6 Nov 2017 16:25:31 +1100, Xeno <xenolith@optusnet.com.au> wrote: >> <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?id 87> Notice amateur Woody is arguing with 2 former professional mechanics and trade school instructors???? I'm done with him. A waste of time, effort and breath. PLONK!! |
| clare@snyder.on.ca: Nov 06 04:44AM -0500 On Mon, 6 Nov 2017 17:23:01 +1100, Xeno <xenolith@optusnet.com.au> wrote: >The past half dozen cars I've had have been FWD. I don't have a problem >with them. My first FWD car was a Morris Mini back in 74 and I have had >heaps of them since. Had heaps of RWD cars too. Totals in the hundreds. 2 mechanics/trade school instrctors who drove Morris Minis ---- |
| Xeno <xenolith@optusnet.com.au>: Nov 07 12:32AM +1100 > 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) Teaching the trade, yes, bound to cause tears at times. >> 4. Tires >> 5. paint > Ond I've dome them all at least once. Done hundreds and hundreds of alignments. >> 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. Ditto. Been there, measured that. ;-) > 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: Overtightening wheel nuts or uneven tightening of same will cause warpage of discs. -- Xeno |
| Xeno <xenolith@optusnet.com.au>: Nov 07 12:35AM +1100 > 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 Exactly. The new pads will charcoal grill on the high spots and *never* properly bed in. > 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. Brake pulling is most likely as the most grooved disc will have less surface contact. -- Xeno |
| Xeno <xenolith@optusnet.com.au>: Nov 07 12:44AM +1100 >> with them. My first FWD car was a Morris Mini back in 74 and I have had >> heaps of them since. Had heaps of RWD cars too. Totals in the hundreds. > 2 mechanics/trade school instrctors who drove Morris Minis ---- First car was a Hillman Minx. Had a few before I bought the mini. 850cc of raw power, 70 mph with a tail wind and a downhill run. -- Xeno |
| Xeno <xenolith@optusnet.com.au>: Nov 07 12:46AM +1100 On 6/11/2017 9:36 PM, Vic Smith wrote: > That "pro" says to replace brake fluid once a year. > I wonder how many people do that. > I never replace brake fluid unless I've got the system open. Every two years at a minimum was what it used to be. The fluid is hygroscopic and will absorb moisture out of the air or anywhere it can. -- Xeno |
| rbowman <bowman@montana.com>: Nov 06 07:26AM -0700 On 11/5/2017 9:48 PM, RS Wood wrote: > is sinking in a pond (pool in their case) where someone mentions to roll > down the windows ... heh heh ... > When's the last time you saw a roll-down window? About 12 hours ago when I parked the car. |
| rbowman <bowman@montana.com>: Nov 06 07:35AM -0700 On 11/5/2017 9:49 PM, RS Wood wrote: > I don't hear anyone talking about pushrods, so, all I see here are that > chains last a*lot* longer in general than do belts, where if either one > broke on an interference engine, expensive things can happen. Unless it's a gear driven camshaft the pushrod design will have a chain. Other than bikes I don't there are many gear drives because of the fitting problems. My Harley has gears but they are factory matched. Aftermarket cams tend to be noisier because of the wider tolerance. |
| rbowman <bowman@montana.com>: Nov 06 07:36AM -0700 On 11/5/2017 9:49 PM, RS Wood wrote: > They make 'em for one reason, and one reason only. > The tradeoffs are legendary, especially in a group that has to DRIVE them > and REPAIR them. Cheaper? No, you're wrong on that one. |
| Ed Pawlowski <esp@snet.net>: Nov 06 09:47AM -0500 On 11/6/2017 1:18 AM, RS Wood wrote: >> why rings would be "better" today than in the days of yore. > I think I got cranky. > Apologies. As an alleged engineer you should be ashamed of yourself. Your thinking lacks logic too, if you think a 1955 Chevy rings is the same as used today. https://upcommons.upc.edu/bitstream/handle/2099.1/22095/Designing%20and%20modeling%20of%20piston%20in%20combustion%20engines.pdf?sequence=1 |
| Ed Pawlowski <esp@snet.net>: Nov 06 10:00AM -0500 On 11/6/2017 1:13 AM, RS Wood wrote: > Just one reference from the entirety of the Internet. > You show it ... I'll read it. > Until then, it's marketing bullshit. Doubt you'll believe it anyway. https://ebcbrakes.com/articles/what-is-brake-fade/ There are principally 2 common types of formulation for a brake pad friction material, organics and sintered metallics (there are also brake pads known as 'semi-metallics' but these are a 'hybrid blend' of the two aforementioned friction types and thus have properties that typically lie somewhere in the middle). For more information on the different brake pad constructions read our article 'How to make brakes'. Organic brake pads inherit their name from the organic phenolic resins used to bind together the different compounds used in the pads construction. There are countless different types of thermoset phenolic resin, but they can all be generally considered to have a maximum temperature up to which they are thermally stable. Above its intended maximum operating temperature, just like any organic matter, the phenolic resin used as the binding agent becomes altered by the heat and effectively 'boils', expelling an appreciable volume of gas as it degrades. (The actual technical term for this process is sublimation, since once the phenolic material reaches the critical temperature it jumps from its original solid state and changes instantaneously to a gas, with no detectable liquid phase). The dominant mechanism causing brake fade is this thermal degradation of the phenolic resins and other materials in the friction lining, which create a film of gas at the pad-rotor interface and effectively causes the brake pad to skid off the disc. As these gasses build up at the pad-rotor interface, they produce an appreciable backpressure which creates an opposing force to the brake caliper that is trying to hold the pads against the rotor. If there is no way for the gasses to escape, the opposing force as a result of the outgassing can become large enough to prize the pads away from the rotor, reducing the area of pad in contact with the rotor and thus reducing braking power (i.e. brake fade). |
| AMuzi <am@yellowjersey.org>: Nov 06 09:04AM -0600 On 11/6/2017 8:35 AM, rbowman wrote: > drives because of the fitting problems. My Harley has gears > but they are factory matched. Aftermarket cams tend to be > noisier because of the wider tolerance. My Corvairs are geared-cam. -- Andrew Muzi <www.yellowjersey.org/> Open every day since 1 April, 1971 |
| clare@snyder.on.ca: Nov 06 10:06AM -0500 On Mon, 6 Nov 2017 18:06:57 +1100, Xeno <xenolith@optusnet.com.au> wrote: >> 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. Since the caster adjustment can only be done some 16 or so inches from the ball joint (have not seen an adjustable lower control arm pivot in decades on a strut suspension) the difference in caster from camber or vice versa is by necessity less than half what it would be if the centers were 8 incges apaty like a typical double wishbone |
| clare@snyder.on.ca: Nov 06 10:07AM -0500 On Mon, 06 Nov 2017 03:32:52 -0500, "Steve W." <csr684@NOTyahoo.com> wrote: >designs fail around 50-60K and do more damage than just the valves if it >drops into the lower sprocket on a stick that rolls a bit. >GMs 3.6 and some others use a VERY light chain that stretches and breaks. "Garbage Machines" |
| clare@snyder.on.ca: Nov 06 10:08AM -0500 On Mon, 06 Nov 2017 02:36:44 -0800, Vic Smith >That "pro" says to replace brake fluid once a year. >I wonder how many people do that. >I never replace brake fluid unless I've got the system open. I generally did when doing any major brake work (drums, rotors, pads or shes) - just s thorough bleed. |
| clare@snyder.on.ca: Nov 06 10:16AM -0500 On Tue, 7 Nov 2017 00:32:45 +1100, Xeno <xenolith@optusnet.com.au> wrote: >> web. What I know comes from tears in the trade (including teaching the >> trade) >Teaching the trade, yes, bound to cause tears at times. Took tech courses at high school - not typing!! - but you are right. Tears of frustration Snipped >>> 5. paint >> Ond I've dome them all at least once. >Done hundreds and hundreds of alignments. Likewize. Thousands of tires. likely at least a hundred transmissions of different stripes, and between total rebuilds, head jobs, timing chains, and other major internal work, several hundred engines. SNIPP |
| clare@snyder.on.ca: Nov 06 10:17AM -0500 On Tue, 7 Nov 2017 00:35:45 +1100, Xeno <xenolith@optusnet.com.au> wrote: >> stupid like installing new pads on badly worn rotors. >Brake pulling is most likely as the most grooved disc will have less >surface contact. Untill it does finally totally wear in - when it will have more - so either way you can't win with grooved/worn rotors. |
| clare@snyder.on.ca: Nov 06 10:19AM -0500 On Tue, 7 Nov 2017 00:44:59 +1100, Xeno <xenolith@optusnet.com.au> wrote: >> 2 mechanics/trade school instrctors who drove Morris Minis ---- >First car was a Hillman Minx. Had a few before I bought the mini. 850cc >of raw power, 70 mph with a tail wind and a downhill run. Thats a GOOD tailwind and a GOOD downhill. My 850 was the only car I've owned that would go faster in third than in forth - and I owned a '49 split-window bug. The mini was faster, but the bug could hold it's own in top gear. |
| RS Wood <rswood@is.invalid>: Nov 06 03:20PM Ed Pawlowski wrote: > Doubt you'll believe it anyway. > https://ebcbrakes.com/articles/what-is-brake-fade/ It's marketing bullshit and it's track related, but it has nuggets inside it just like all bullshit does. For example, it's interesting they don't mention the rotor (but of course, they're selling pads) when they say "Brake fade is caused by overheating of the brake pad". It's also interesting they talk about 'green fade' which makes sense since a more complex look at friction reveals that there is a microlayer of pad deposition on the rotor which "covalently bonds" in a way that I don't completely understand, with the hot pad, where *breaking* those chemical bonds adds to friction but only after a good bedding occurs. They skip all that, and concentrate on water, surface area, and volatiles, but I think the early fade is due more to the lack of covalent bonding than anything else. I gotta run so I'll get back to this, but it's a typical marketing job trying to make believe they're being scientific when they don't mention even once the pad ratings nor the word "warp", but I have to go before I finished it as I have to pick someone up at the airport. |
| RS Wood <rswood@is.invalid>: Nov 06 03:20PM Xeno wrote: >> rebuild than a manual would be for a typical rebuild. > Far more than most people realise. Even more complex now that trans > operation is integrated with a TCU and the ECU. When I listed transmission in the original post, I meant manual, and specifically I meant clutch which, as you know better than I do, means a few more parts like a. clutch b. pressure plate c. pilot and throwout d. slave and master e. flywheel I'm not sure what else offhand, but had I just done the job once, I'd know. I think the only "special" tools needed are a transmission jack and the tools to align the clutch and pull out the old bearings where people jury rig all sorts of solutions but where I'd likely buy the right tool. Seems to me the special tools are about $200 to $300 at most, which is about what the labor costs would be. And the job isn't like an alignment where you have to do a lot more than normal thinking. Maybe some day I'll do it but probably never. I lost my chance, and I regret that. |
| RS Wood <rswood@is.invalid>: Nov 06 03:20PM Vic Smith wrote: > That "pro" says to replace brake fluid once a year. > I wonder how many people do that. > I never replace brake fluid unless I've got the system open. I agree with you that the so-called "pros" say a lot of things that are pure horseshit, but usually they're just super overly conservative (like have your tires balanced every 10K miles or something like that). You can't call them "wrong" but you can say "nobody does that". I would agree with you on two things related to those articles: a. I don't agree with everything they say (they don't even agree with each other). b. But the net is that what most people call warp isn't warp at all. There are few technical car topics on the net more filled with bullshit than rotor warp for street cars. Nobody who says they have seen warp ever proves a single word they say. That's a fact. Just try to find a picture or video of someone testing their rotors for warp (not runout!) and you'll see my point. I'm done with warp because I provided references and I said it "can" happen but it's not happening in 99.9999999% of the cases. Anyone who wants to dispute the references need only provide a reference. |
| RS Wood <rswood@is.invalid>: Nov 06 03:20PM > 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. Rotors are cheap. $50 for Brembo or Myle. I measure runout. I measure thickness. I measure thickness variation. I look at scoring. I look up the specs when I need them. In practice, it's pretty simple: 1. Replace the OEM Jurid/Textar pads with $35 Axxis/PBR FF equivalents. 2. Measure the thickness of the existing rotor 3. If it's too thin, replace with Meyle/Brembo for $50/wheel I don't blame any shop for replacing *everything* they can. The more they replace, the more they make and the less people come back. That's just logic. |
| RS Wood <rswood@is.invalid>: Nov 06 03:20PM Xeno wrote: > The pads on my car(s) have both long life and good braking ability. Did > I mention they don't squeal too. They are the OEM Toyota pads that came > with the car and that's what they will be replaced with. The only time you don't have to mention the friction rating is when you purchase OEM pads. Otherwise, the friction rating is critical to mention. I have nothing against OEM anything, but in the case of the bimmer, the FF Jurid pads in the front make a black dust that is objectionable. For some reason, which I don't believe the marketing of, the PBR/Axxis FF pads don't have that objectionable dust. Nobody has ever given a good answer since "dustless" doesn't cut it. All pads and rotors must dust. So we just assume that the dust from Axxis/PBR pads is not as objectionable as the dust from the OEM Jurid pads. Both stop as well as indicated by the FF rating for both. |
| RS Wood <rswood@is.invalid>: Nov 06 03:20PM > Not hard to understand at all. Uneven friction causes uneven heating, > and localized overheating causes enhanced friction material transfer - > which just cascades. That must be it because you don't feel the effect of the primary pad imprint. You only feel the effect over time when it builds up to enough of the teeniest tinyiest amount to make the shuddering occur at speed. My main point is that if people think their brakes actually 'warped' (ad in a potato chip), the short term solution always works but their long term solution can't possibly work. The long term solution is, most of the time, to change their braking habits. Until they realize that their brake rotors didn't warp, they won't realize that the long term solution is what it is. To me, that's the crime of people thinking their brakes actually warped. > 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. I know. I know. But I was summarizing. You can scrape the deposit off a bunch of free and easy ways. 1. Easiest is to run the re-bedding procedure 2. Easy but harder than that is to put some scratchy pads on 3. Harder than those two by far is to have them machined or replaced I do what you do, which is I rebed them which is easily enough done if you have a long downhill straightaway with no traffic or a highway straightaway with no traffic. In summary, the *crime* of people believing that the rotors actually warped is that they never implement the correct long term solution. So they're constantly complaining that their rotors warped. |
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