Brakes squeal!!!!

Actually it is the internal "O" ring that pulls the piston back, not the outer boot on most calipers.

Reply to
nospam.clare.nce
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Reply to
mic canic

Yes, the "O" ring seals the caliper, but it also "bends" a but as the piston slides though - and when the pressure is released, the "O" ring straightens back out, pulling the piston back in just a smidge. This gives the clearance. Take a good look at the boot, flex it around - then try to push the piston back with your fingers. Note how little resistance the boot gives to being deformed - and how much force it takes to move the piston. Absolutely no way the boot could handle pulling the caliper back.

Your instructor at Chryaler only taught you half of the story.

I've taught it too - and I've tried to get the whole story told.

Reply to
nospam.clare.nce

I've used lots of cheapo chinese rotors in my cars since I don't turn rotors, just throw them away if they are grooved. The only difference between the cheap chinese rotors and the better rotors is the quality of the steel, the chinese rotors aren't heat treated to the point that they will stand up to a lot of heat, thus they are prone to warping. Otherwise the machining quality is generally very good.

However, there is a trick to using these rotors. Chinese cheapo rotors work fine if you learn how to brake properly. And braking properly means driving properly. That means when you see a stoplight up ahead, you let off on the gas and coast to the stop, only braking gently near the end. You don't floor it until you get within

100 feet of the stoplight and then slam on the brakes. Another thing you don't do that I see people doing all the time is drive around with their brakes on practically all the time. I see this on the freeway every day. People nose up to the car in front of them until they are tailgating on his ass then he slows down a little bit and they have to brake. Whereas I let a good 3-4 seconds of distance from the car in front of me, and if he brakes quite often I simply let up on the gas and have plenty of space to coast down until I'm matching his speed again.

The harder and longer you brake the more kinetic energy is dumped into the brakes and the hotter and hotter they get. And also the more fuel you waste. Since the average American driver doesen't appear to understand this, no wonder so many of them complain about warped rotors.

Ted

Reply to
Ted Mittelstaedt

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Too bad you spoiled an reasonable treatise with a foray into metallurgy. Rotors aren't made of steel. Heat treatment isn't done to provide heat resistance, it's done to provide enhanced properties....and it isn't done on rotors anyway.

Reply to
cavedweller

Glad you got it fixed!

BTW - the things that are being called "anti-rattle" clips (I think that's a misnomer) are one of two types. One type is just a wear surface between the pads and the rub points on the steering knuckle. There is also a differenet type that is actually a pad spreader - keeps a little spring force outward on the pads that helps retract them away from the rotor. You can use either type, but only one type at a time. The second type, though shown in the FSM, were not available from DC until a few months ago - if you ordered them, what you got were the wear bars. I'm glad they made the retractors avaialable - they are bound to help in rotor wear and heat (warp).

So which type did you put on? To see photos, look at my third post (the one with the photos) in this thread on the 300M Club forums:

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first two photos are of the pad retractors; the second two photos are of the wear bars. Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Reply to
Bill Putney

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The first two photos are of the pad retractors; the second two photos are > of the wear bars.

Reply to
Dan

Very good. There never were any for the rears.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Reply to
Bill Putney

To my knowledge (and its fairly good...) Chrysler hasn't used a brake system "of their own manufacture" since AT LEAST 1965, and I'm guessing more like 1955. It as far as disk brakes go, been 99% K-H since 65, with a few odd Bendix applications (4-piston front calipers on '67-69 B-bodies and some A-bodies) and Budd (~66 C-bodies and a few others) over that time.

AMC used Delco Moraine, Bendix, and

Bullfeathers. GMs squealed just as much as Chryslers ever did, if not more. Seems like every GM A-body that drove by me in the 80s (Regals, Cutlasses, MonteCarlos" were squeaking away.

Reply to
Steve

Yes you are right, for stockers, however:

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Your right, what was I thinking! I was too caught up in the issue of not creating the heat to begin with I'm afraid.

However, while stock rotors may not be heat treated, heat treating is in fact, done on some rotors, see here:

From:

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"These rotors feature increased "mass" or "weight" in the "fire path" which is the point of pad contact, along with curved and directional vanes, combined with balancing and heat treating, ensure EradiSpeedT rotors "

-------------------------------------------------^^^^^^^^^^^^^^^^^^

Ted

Reply to
Ted Mittelstaedt

I remember a couple years ago when I was toying with the idea of putting together a "showroom stock" VW (before I figured out that I just couldn't afford to do it right, and it would have to be my daily driver) that cryogenically treated rotors were the, ahem, hot ticket. I'm curious if a) anyone has any experience with them and do they live up to the hype and b) would it be worthwhile to have a set of rotors frozen for a regular use passenger car that has a rotor warping problem?

nate

Reply to
Nate Nagel

I was just getting ready to post these two links in response to Ted's post, when you beat me to it:

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I have used both their products (they both pretty much use Raybestos rotors that they run thru their cryo process). Presently I have Frozen Rotor (Diversified Cryogenics) front rotors on my '99 Concorde (rear brakes on LH cars are 99% problem-free with no special efforts or products).

LH cars are very prone to brake vibration - I have many theories on why, and not all are related to rotor warping. They actually do use cryo rotors in racing. They wouldn't without good reason. It is clear that cryo treatment does change the properties of metal. They prolong the life of welding tips and engine parts (in extreme conditions).

Anyway, the Frozen Rotors apps. engineer also talked me into a set of Performance Friction 'Z-Rated?' pads (very reasonably priced:

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I can tell you that the combination is working *very* well for me (I'm presently experiencing the longest period of totally vibration-free brakes I've had with this car). Brakes are absolutely smooth operating. To be honest, I cannot tell you how much pads play a part in vibration-free brakes and how much rotors play - that gets back to my theories of the various real-world causes of brake vibration, at least as related to LH cars. I can say that the combination of the Frozen Rotors and the PF Z-Rated pads has done the trick for my Concorde (80 mile daily commute). Would I get the same results with the PF pads and non-treated rotors? Can't say.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Reply to
Bill Putney

Certainly, see below.

"Stocker" is understood......I only offered the comment within the scope of r.a.m.c. You may have noticed the inappropiate preposition "an" in my original post...I had used the word "excellent" initially but then decided that was going a little too far. :)

Reply to
cavedweller

me results with the PF pads and non-treated rotors?

Cryogenic treatments for steels are valid when the objective is to eliminate retained austenite and drive the martensitic (hardening) transformation to completion. The anture of the mechanism and to what extent it's effective in production rotor material (grey cast iron) isn't clear to me.....

Reply to
cavedweller

They claim that carbide precipitates out, with one result being increased hardness, slower wear, and more stable and uniform structure. Maybe that's another way of saying what you did about the retained austenite (it's been 30 years since I had the metallurgy courses in the engineering curiculum in which all that stuff was covered in detail).

"Anture"? Is that a typo - I'm not familiar with that word. Never mind

- just figured it out - "nature". Got it.

Anyway, you might delve into some of the technical pages on the 300 Below and Diversified Cryo sites. What I read made sense with what I do remember from my engineering courses regarding grain structure, phas transition, etc. You appear to have the right technical background for critical reading of same.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Reply to
Bill Putney

Typos are contagious. "phase"

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my adddress with the letter 'x')

Reply to
Bill Putney

Steels and irons all have carbides in varying form and degree. After all, the equilibrium system is iron/iron carbide.(Fe3C)

Nope. (it's been 30 years since I had the metallurgy courses in the

Yep

Reply to
cavedweller

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