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Home > Archive > Home Repair forum > July 2005 > Re: Car Brakes Squeaking
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Re: Car Brakes Squeaking
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| deans@wdeans.com 2005-07-24, 9:10 pm |
| Greetings,
Isn't there a car newsgroup somewhere???
If your rotors are scored don't let them tell you that you need new
ones. Unless they are BADLY scored or thin you can sand them. If you
want new ones cheap often cars go to the junk yard with almost new
rotors. Look at 4 sets and odds are you will find one with 80% or
better of its life remaining. Rotors cost $10 each at my junk yard for
a savings of over $100 for about 1/2 hours work (once you are to the
yard).
I also tell everyone they should replace their own break pads. It
normally doesn't take me more than about 20 minutes if I don't bleed
the breaks and maybe 30 if I do. Brand new pads cost about $5 per
wheel. Since, depending on your families driving habits, you may have
to replace a set as often as once per year, I recommend taking the time
to learn. It will save you thousands over your lifetime and it is so
quick it is hardly worth taking the time to drop off your car and pick
it up later even if the replacement was free.
Hope this helps,
William
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| JerryL 2005-07-24, 9:10 pm |
|
> I also tell everyone they should replace their own break pads. It
> normally doesn't take me more than about 20 minutes if I don't bleed
> the breaks and maybe 30 if I do. Brand new pads cost about $5 per
> wheel. Since, depending on your families driving habits, you may have
> to replace a set as often as once per year, I recommend taking the time
> to learn. It will save you thousands over your lifetime and it is so
> quick it is hardly worth taking the time to drop off your car and pick
> it up later even if the replacement was free.
>
> Hope this helps,
> William
>
What kind of crap pads are $5 a wheel? Secondly, telling someone who knows
nothing about brakes to do their own brake job or change their own rotors
is almost like giving them a loaded gun and telling them to pull the trigger
while aiming at their loved ones. You might know how to do a brake job but
99% of the rest of the world doesn't.
Have you ever had brain surgery? Why not do it yourself? Do you know how
much money you could save?
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| Oscar_Lives 2005-07-24, 9:10 pm |
|
"deans@wdeans.com" <William.Deans@gmail.com> wrote in message
news:1122149688.488919.136360@f14g2000cwb.googlegroups.com...
>
> The same kind that comes on a brand new car rolling out of the factory.
> AutoZone VALUCRAFT SEMI-METALLIC part number MKD215V with 1 year
> warranty are the kind that I have on one of my own vehicles. Guess
> what? They cost 9.99 for a set which does both front breaks. I also
> believe that tap water is safe to drink and that I do not need to pay
> up to $1 per bottle for water from a spring. My shoes do not have an
> air pump so one day a Tiger might outrun me and eat me. I'll fly on
> AirTran (ValueJet) to Atlanta. I guess I am just a stupid idiot.
> Hopefully my healthy diet, exercise, and continued mental activity will
> more than make up for it.
>
>
> You are right. If someone gave me a loaded gun and told me to pull the
> trigger while aiming at my loved ones I would know just what to do with
> that loaded gun after they handed it to me. I don't think our readers
> are stupid. They can follow some steps and figure out what to do with
> the break pads.
>
>
> If I could learn how to do brain surgery myself in an hour following a
> single page of steps and if I wasn't satisfied with the results I could
> take the brain into a hospital to be reviewed and possibly redone by a
> brain surgeon why not? Especially if the brain surgen looked like the
> guy at Midas and didn't have a high school degree. Especially if I
> also had an emergency brain I could call upon. Especially if the most
> complex organ in the human body perhaps never to be fully understood
> were as simple as break pads. Unfortunately this isn't at all what
> brain surgery is like and so I prefer to leave it up to the
> professional.
You can't even spell a simple word like "brake". You have no credibility
here.
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| JerryL 2005-07-24, 9:10 pm |
|
"deans@wdeans.com" <William.Deans@gmail.com> wrote in message
news:1122149688.488919.136360@f14g2000cwb.googlegroups.com...
>
> The same kind that comes on a brand new car rolling out of the factory.
> AutoZone VALUCRAFT SEMI-METALLIC part number MKD215V with 1 year
> warranty are the kind that I have on one of my own vehicles. Guess
> what? They cost 9.99 for a set which does both front breaks. I also
> believe that tap water is safe to drink and that I do not need to pay
> up to $1 per bottle for water from a spring. My shoes do not have an
> air pump so one day a Tiger might outrun me and eat me. I'll fly on
> AirTran (ValueJet) to Atlanta. I guess I am just a stupid idiot.
> Hopefully my healthy diet, exercise, and continued mental activity will
> more than make up for it.
First of all, auto manufacturers buy millions of brake pads and yes, they
can purchase them a little cheaper than you, who buys one set of pads every
couple of years can buy them.
If you choose to use a cheap set of pads on your car, that's your choice.
But to tell a person who knows nothing about brakes that they should avoid
going to a mechanic to have their brakes installed or checked and that they
should do it themselves without any knowledge of brake systems leads me to
believe that you are a complete idiot.
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| JerryL 2005-07-24, 9:10 pm |
|
"deans@wdeans.com" <William.Deans@gmail.com> wrote in message
news:1122155504.613031.177100@g14g2000cwa.googlegroups.com...
> Greetings,
>
>
> Car manufacturer's prices are not lower simply because they purchase in
> bulk. They are also lower because they are free from such notions as
> the more expensive a pad is the safer it is.
All pads will stop the car. Better pads will react to the heat differently
and will not fade after repeated brakings. Pads originally were made from
asbestos. Besides being a carcinogenic, they wore out extremely fast when
used as disk pads. They also didn't react properly when subjected to the
high temps of repeated braking. Then metallics came out to try and solve
that problem. The first semi-metallics lasted longer, performed better but
were noisy and harsh on the rotors. Now they have ceramic, kevlar which is
not afftected by the heat as much, are easy on the rotors, put almost no
dust on your wheels and guess what? They cost a hell of a lot more.
So don't condemn people for spending more for pads than you do. There are
reasons for it.
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| Mark and Kim Smith 2005-07-24, 9:11 pm |
| deans@wdeans.com wrote:
>Greetings,
>
>And do most auto-manufactures use Kevlar pads on their new cars? Did
>you replace the pads on your car hot off the lot? You asked who used
>the $5/brake pads and I said the auto manufactures. You countered that
>the savings came from buying in bulk but it sounds to me that by your
>definition manufactures in fact save by using so called "crap pads!"
>You most certainly can pay more for z-Rated pads, etc. but believe it
>or not these "crap pads" for $5 per brake will perform equally well
>to the $50 per brake z-Rated pads available because the limiting factor
>on brake performance at any legal speed within my state is not the
>stopping power of the pad but instead the traction of the tires. My $5
>per brake pads can provide MORE stopping power without overheating than
>my tire traction is able to handle. Different pads WILL NOT increase
>braking performance.
>
>Hope this helps,
>William
>
>
>
Yikes! Do me a favor and don't drive behind me! I don't feel like
having the hassle of repairing my car when you crash into it!
Different pads will not increase braking performance??!!??!?!?!?!?
Where'd you get that from??
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| JerryL 2005-07-24, 9:11 pm |
|
"deans@wdeans.com" <William.Deans@gmail.com> wrote in message
news:1122160340.906967.207920@o13g2000cwo.googlegroups.com...
> Greetings,
>
> And do most auto-manufactures use Kevlar pads on their new cars? Did
> you replace the pads on your car hot off the lot? You asked who used
> the $5/brake pads and I said the auto manufactures. You countered that
> the savings came from buying in bulk but it sounds to me that by your
> definition manufactures in fact save by using so called "crap pads!"
> You most certainly can pay more for z-Rated pads, etc. but believe it
> or not these "crap pads" for $5 per brake will perform equally well
> to the $50 per brake z-Rated pads available because the limiting factor
> on brake performance at any legal speed within my state is not the
> stopping power of the pad but instead the traction of the tires. My $5
> per brake pads can provide MORE stopping power without overheating than
> my tire traction is able to handle. Different pads WILL NOT increase
> braking performance.
>
> Hope this helps,
> William
And I hope this helps. Any person that thinks the traction of their tires is
stopping their car instead of the pads is an idiot.
| |
| Mark and Kim Smith 2005-07-24, 9:11 pm |
| deans@wdeans.com wrote:
>
>Do you think that the $5/brake pads should be taken off the market?
>
>
No, I think the way you approach and do brake jobs should be taken off
the market.
>
>
>
>I just explained that. Please explain to me how different brake pads
>could stop my car any faster so long as the ones I have are able to
>apply any amount of stopping power up to and including enough to lock
>the wheels.
>
>
>
You didn't understand the thread about different friction materials and
different friction rates would apply?? Locking up the wheels is not a
goal! Once you have locked up the wheels, you have lost control!
Between applying brakes and the wheels locking up is stopping distance.
Different friction materials will result in different stopping distances.
Now, if you still think locking up the wheels is a good thing, don't get
behind me if you are driving in wet or icy conditions. If you feel that
locking up your wheels is a good thing on a dry day in dry driving
conditions, then please let me know how you have mapped out every oil
slick on every road out there. Why do you think anti-lock brakes stop
in a shorter distance than regular brakes?? Tire friction is not the
best way to stop your car! Brakes are!
| |
| JerryL 2005-07-24, 9:11 pm |
|
"deans@wdeans.com" <William.Deans@gmail.com> wrote in message
news:1122163954.482219.17740@g14g2000cwa.googlegroups.com...
>
> Do you think that the $5/brake pads should be taken off the market?
>
>
> I just explained that. Please explain to me how different brake pads
> could stop my car any faster so long as the ones I have are able to
> apply any amount of stopping power up to and including enough to lock
> the wheels.
>
Did you ever hear of 'brake fade'. It's caused by excessive heat on the
pads. When the pads heat up they will not stop the car normally.
| |
| Mark and Kim Smith 2005-07-24, 9:11 pm |
| deans@wdeans.com wrote:
>
>No one here has suggested that the traction of the tires stops the car.
> The basic physics you are overlooking is that the pads can only stop
>the car if the tires are spinning. If you try to brake too fast the
>tires will stop spinning and you will slide to a stop over a GREATER
>distance than if you had not braked so fast as to lose traction. This
>is why anti-lock brakes intentionally limit the amount of breaking your
>pads produce when your wheels start to slide. So you see that even
>though it is the pads which stop the car their maximum braking
>potential is actually governed by the tire traction. Pads which are
>able to reach this upper limit of friction for the entire duration it
>takes to stop the car will all stop the car equally fast -- no matter
>how much or little they cost.
>
>
>
'cept that you have forgotten about pedal effort. Plus, different
friction materials will act differently because no one uses brakes from
0 effort to maximum or upper limit. Pedal effort. Different friction
materials, different stopping rates. And different friction materials
means different costs.
| |
| Mark and Kim Smith 2005-07-24, 9:11 pm |
| deans@wdeans.com wrote:
>
>I grow very tired of defending myself from statements I did not make.
>Locking up the wheels is a BAD thing; the coefficient of static
>friction is higher than the coefficient of dynamic friction. Having a
>pad capable of exerting the stopping power necessary to lock up your
>wheels is a GOOD thing. This is because the greatest deceleration is
>achieved by ALMOST locking up the wheels coming right up to the brink
>of locking them but NOT locking them.
>
>
Okay, if you didn't say that, you didn't say it. I must have misunderstood.
>
>
>
>I don't understand this nonsense. Can someone else please confirm that
>this is nonsense? What do oil slicks have to do with this? Are you
>saying locking your wheels on a dry day would be a good thing except
>for all those oil slicks?
>
>
Not nonsense if you had believed that locking up wheels was a good
thing. Disregard.
>
>
>
>No, apparently I didn't understand the science behind it. I am not
>trying to put words in your mouth but I think you were trying to say
>that different pads would produce different amounts of drag on the
>rotor with the same pressure exerted by the caliper because they are
>made of different materials? If so, you are correct, but it doesn't
>matter. My original statement was that any pad, no matter what the
>cost, would stop you in an equal distance so long as it was able to
>generate as much friction against the rotor as the tire traction would
>allow for without locking. This statement still holds true.
>
>
Except that you leave too many variable out. Any pad?? Okay, I'll give
you a set of my specially made teflon pads. Tell me you can generate
enough pedal pressure to create the friction equal to a semi-metallic
pad. You can't do it, the system isn't design for it. Bring it up to
max pressure without locking? The teflon would give you lubricating
properties. All pads are not created equal!
Or let's try this. Your pads have lost all their material. You are now
stopping with brakes metal to metal. Bring your caliper pressure up to
but not locking the wheel. That direct metal will give you a lot more
"grab" than a pad with material. The friction happens quicker and more
aggressively. You will slow quicker. In a shorter distance than pads
with material.
Remember, we are talking about vehicle brake systems, not a "perfect"
world where everyone reaches max pressure without locking. Different
diameter rotors, different size pucks, different size pistons, etc,
etc. Pad material makes a difference.
But enough, I don't like talking "work" on my weekends!
| |
|
| deans@wdeans.com wrote:
>
>
> Do you think that the $5/brake pads should be taken off the market?
>
>
>
>
> I just explained that. Please explain to me how different brake pads
> could stop my car any faster so long as the ones I have are able to
> apply any amount of stopping power up to and including enough to lock
> the wheels.
>
Envision this experiment:
Set up two axles so that you can apply the same constant external torque
to each. Set up a hydraulic disc brake on each axle, each brake
actuated by the same hydraulic line. Put pads of different materials on
each brake. Now apply the external torque and apply hydraulic pressure.
The worse pads are the ones that lock their brake first.
You can actually do this experiment by putting pads of different
materials on the front brakes of a non-ABS car. Probably it would be
safer to run the experiment on rear brakes. Apply the brakes and check
for skid marks. You will find that the side that skids has less
stopping power---the front of the car will turn toward the side that
doesn't skid.
You may not sue me if this experiment causes property damage, personal
injury, or loss of life ...
| |
| G Henslee 2005-07-24, 9:11 pm |
| deans_an_asswipe@wdeans.com wrote:
> Greetings,
>
> Isn't there a car newsgroup somewhere???
>
What do you care, or even know? When not screwing it, you ride a mule
anyway...
| |
|
| deans@wdeans.com wrote:
> As I apply hydraulic pressure the wheels will slow. The Teflon wheel
> will always spin faster than the Asbestos wheel at a fixed external
> torque and certain hydraulic pressure. Eventually the Asbestos pad
> wheel will stop once the hydraulic pressure is high enough. Later the
> Teflon pad wheel will come to a stop once the pressure is still higher.
>
>
>
>
> Why? Why is the Asbestos pad worse than the Teflon one just because it
> locked the brakes first? I don't get it.
I didn't quite get that right.
Let p be the hydraulic pressure at which the brake locks up and let c be
the coefficient of sliding friction between the pad and the rotor at p -
delta, where delta is small. The better brake is the one for which c *
p is the larger.
I wrote and you seem to have missed:
> Apply the brakes and check for skid marks. You will find that the side that skids has less stopping power---the front of the car will turn toward the side that doesn't skid.
| |
| JerryL 2005-07-24, 9:11 pm |
|
"Matt" <matt@themattfella.zzzz.com> wrote in message
news:DVMEe.2500$j21.657@news01.roc.ny...[color=darkred]
> deans@wdeans.com wrote:
>
Regardless of type (disk or drum), your brakes work by pressing a
non-revolving material against a revolving material and, as a result,
converting (via friction) the energy from the revolving material into heat.
The harder the materials are pressed together, the greater the friction and,
as a result, the greater the rate of conversion - i.e., the more braking
force applied, the quicker you slow down the revolutions of the wheels, and
the hotter the brakes become.
The brakes are also designed to radiate the resulting heat into the
environment and, thus, allow the brakes to cool down quickly after they are
no longer being used. This is a very important part of their design because
the braking material used loses efficiency (reduced friction) with high
heat. Indeed, if the braking material gets too hot it can be permanently
damaged (it will glaze.)
| |
| Duane Bozarth 2005-07-24, 9:11 pm |
| JerryL wrote:
>
> "Matt" <matt@themattfella.zzzz.com> wrote in message
> news:DVMEe.2500$j21.657@news01.roc.ny...
>
> Regardless of type (disk or drum), your brakes work by pressing a
> non-revolving material against a revolving material and, as a result,
> converting (via friction) the energy from the revolving material into heat.
> The harder the materials are pressed together, the greater the friction and,
....
....for a given rotor/pad material combination...
| |
| jim evans 2005-07-24, 9:11 pm |
| How is this thread related to home repair?
<Theoretical discussion of friction in the context of automotive
braking systems snipped.>
jim
| |
| Edwin Pawlowski 2005-07-24, 9:11 pm |
|
"jim evans" <jimsTAKEOUTnews2@houston.rr.com> wrote in message
news:g3s7e11cc8q12b06c2b7kgs5a72brqahtv@4ax.com...
> How is this thread related to home repair?
>
> <Theoretical discussion of friction in the context of automotive
> braking systems snipped.>
>
> jim
Hypocrite. You complain this is not on topic, yet you have the balls to
attempt to post a binary attachment in another post. Binary is binary and
does not belong in this group no matter the size.
| |
|
| jim evans wrote:
> How is this thread related to home repair?
>
> <Theoretical discussion of friction in the context of automotive
> braking systems snipped.>
>
> jim
Any thread is relevant to any group if the OP precedes the title by "OT".
| |
|
| deans@wdeans.com wrote:
>
>
> I didn't miss that. The side which skids first will be the Asbestos
> pad side, not the Teflon pad side making Asbestos worse than Teflon
> under your theory. Also, the car will turn towards the right OR the
> left when for example, the right wheel locks DEPENDING ON PAD MATERIAL
> because you have dislike pads. The tires sliding on the road might
> still be providing more drag than the Teflon pad at the pressure the
> Asbestos pad would lock the brakes resulting in the car turning TOWARDS
> the skidding tire.
But not if you increase the brake pressure to just less than what would
lock up the teflon brake.
Please state whether you agree that either brake will do better at a
pressure slightly less than what causes it to lock up and skid.
> The car is guaranteed to turn AWAY from the
> skidding tire with like pads but could go either way with dislike pads.
'unlike' not 'dislike'
Wheels with like pads will skid at about the same pressure.
| |
|
| deans@wdeans.com wrote:
>
>
> If you can create pressure causing friction slightly less than enough
> to lock up the brakes without causing brake failure for the duration of
> the stop all brake pad materials will perform equally well.
I don't think you have dealt with that c * (p-delta) expression that I
mentioned. You have to notice that both c and p depend on the pad
material, p-delta being the pressure just prior to lockup and c being
the coefficient of sliding friction prior to lockup.
I am not an expert, but I think you are wrong. I don't think you are an
expert either. Are you saying that the expensive pads are some kind of
gimmick? Maybe supported by some grand sinister propaganda effort? I
suppose it's possible, but how about citing some expert sources that
support your claim? There must be some---maybe put out by the companies
that make $9.99 pads.
And to be fair to yourself, I think maybe you ought to test your claim
by putting pads of different materials on opposite-side brakes. Just
don't do it in a top-heavy vehicle or on a busy road. Standard
disclaimers apply. I guess you are saying that the driver won't be able
to detect that the brake pads don't match.
| |
|
| deans@wdeans.com wrote:
>
>
> If you can create pressure causing friction slightly less than enough
> to lock up the brakes without causing brake failure for the duration of
> the stop all brake pad materials will perform equally well.
Did you give up trying to find an expert or anyone else who agrees with you?
| |
| JerryL 2005-07-29, 2:21 pm |
|
"Matt" <matt@themattfella.zzzz.com> wrote in message
news:lPsGe.2609$cg.645@news02.roc.ny...
> deans@wdeans.com wrote:
>
> Did you give up trying to find an expert or anyone else who agrees with
> you?
I was going to ask him if he buys his tires with the same logic he uses on
buying brakes.
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