Noisy Brakes

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Noisy Brakes

Postby Silvergun » Fri Apr 01, 2005 2:19 pm

Does any know a quick way of stopping squeaky brakes??

when im braking at about 30% they make that horrible high pitch brake noise. is there any spray etc i can use on them to stop it??
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Postby mr pad » Fri Apr 01, 2005 3:03 pm

How old are your pads dude? I had an ae92 and when my rears started squeaking real bad I took them apart and replaced the pads, the old ones were nearly completly worn down.
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Postby ATAl » Fri Apr 01, 2005 3:37 pm

They are supposed to squeak when the pad is really low, if the pad is not low then it is probably the backing plates causing the noise.

Repco sell something call disc brake noise stop or something like that, get that stuff, pull your pads and backing plates out, spray the stuff all over the back of the pads and plates, reassemble quickly before the stuff sets and the squeaking should be gone.
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Postby Silvergun » Fri Apr 01, 2005 3:53 pm

thanks, will give me something to do this weekend i guess. might even paint the callipers while i got them off.
the noise really pissed me off the last couple of weeks.
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Postby GT4 20 » Fri Apr 01, 2005 4:13 pm

In the good ol' days, most pads had wire running thought them so that when the pad got down to a minimum safe thickness, teh wire was 'broken' which illuminated a light on the dash telling the driver that the pads needed changing.
Problem is that people ignored the light (or even disconnected the bulb!) which is why these days, a metal strip is built into the pad which comes into contact with the rotor when the pad thickness is low. This way, the average motorist will realise that their pads need changing and for the erst, due to the awful noise, they simply can't ignore it :wink:
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Postby mr pad » Fri Apr 01, 2005 4:17 pm

'like nails on a chalk board'
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Postby vvega » Fri Apr 01, 2005 4:36 pm

GT4 20 wrote:In the good ol' days, most pads had wire running thought them so that when the pad got down to a minimum safe thickness, teh wire was 'broken' which illuminated a light on the dash telling the driver that the pads needed changing.
Problem is that people ignored the light (or even disconnected the bulb!) which is why these days, a metal strip is built into the pad which comes into contact with the rotor when the pad thickness is low. This way, the average motorist will realise that their pads need changing and for the erst, due to the awful noise, they simply can't ignore it :wink:
Gary


/me gets out the side cutteder and removes said tag to give me "a few more miles" and then forgets to do it :D

it dosent mattter how you do it people will think of a way to stuff it up lol
stupid people

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Postby mr pad » Fri Apr 01, 2005 4:42 pm

Thats so rangi, its pure class.
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Postby Dr-X » Fri Apr 01, 2005 8:43 pm

The pad squeaking is actually not caused by friction between the rotor and the pad (unless the pad is significantly worn), but between the pad backing and the caliper. Put a spot of grease on the back of the pad where it contacts the caliper, that will eliminate squeaking in 90% of cases.
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Postby GT4 20 » Sat Apr 02, 2005 9:04 am

Dr-X wrote:The pad squeaking is actually not caused by friction between the rotor and the pad (unless the pad is significantly worn), but between the pad backing and the caliper.


ROBODISCO_20v wrote:
Dr X you're a fcuking idiot




Not often I agree with ROBODISCO_20v :lol:
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Postby NZ_AE86 » Sat Apr 02, 2005 9:25 am

GT4 20 wrote:
Dr-X wrote:The pad squeaking is actually not caused by friction between the rotor and the pad (unless the pad is significantly worn), but between the pad backing and the caliper.


ROBODISCO_20v wrote:
Dr X you're a fcuking idiot




Not often I agree with ROBODISCO_20v :lol:


Well once again Dr-X could be correct! Obviously if your pads are worn to the warning tags then they will squeal as they make contact with the disc. In alot of cases though the noise is from the back (caliper side) of the pad! If you go to repco and purchase some 'disc brake quiet spay' read the instructions and it will tell you to spray the back of the pads before installation, it leaves a tacky surface and stops the vibration between the pad and caliper that causes these noises on light brake application. Also, you know the shims on the back of most brake pads are refered to as 'anti-squeal shims' but when people replace their brake pads and don't know what they are doing they will often chuck these shims away and this can cause a squeal under light braking!
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Postby Dr-X » Sat Apr 02, 2005 9:33 am

GT4 20 wrote:
Dr-X wrote:The pad squeaking is actually not caused by friction between the rotor and the pad (unless the pad is significantly worn), but between the pad backing and the caliper.


ROBODISCO_20v wrote:
Dr X you're a fcuking idiot




Not often I agree with ROBODISCO_20v :lol:


And once again, someone is here to argue with me when they dont know the facts. I read a VERY good technical article put together from university research on the topic, which I wish I could find right now.
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Postby vvega » Sat Apr 02, 2005 9:45 am

Dr-X wrote:
GT4 20 wrote:
Dr-X wrote:The pad squeaking is actually not caused by friction between the rotor and the pad (unless the pad is significantly worn), but between the pad backing and the caliper.


ROBODISCO_20v wrote:
Dr X you're a fcuking idiot




Not often I agree with ROBODISCO_20v :lol:


And once again, someone is here to argue with me when they dont know the facts. I read a VERY good technical article put together from university research on the topic, which I wish I could find right now.


you are correst about the backing pad making the noise
however putting a spot of grease on the back is just plain stupid
i cant stress that enought

there are ruberised sprays you can buy that adress this very issue
dr-x if your gunna give advice give good advice
you got the diagnosis correct but i would sue any mofo that puts grease anywhere near my pads rotors and seals.its simply not on at all

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Postby Dr-X » Sat Apr 02, 2005 11:23 am

WTF? There's nothing wrong with putting a spot of grease between the pad backing and the caliper/piston.
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Postby Mr Revhead » Sat Apr 02, 2005 11:27 am

yes, putting grease near ya brakes is a good idea! :lol:


what happens to grease when it gets hot dr-x......
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Postby vvega » Sat Apr 02, 2005 11:35 am

Dr-X wrote:WTF? There's nothing wrong with putting a spot of grease between the pad backing and the caliper/piston.


mate it is utterly dumb you gotta stop this shit
dont give out dangeriuos advice this is worse than the you dont need spring compressors threed

tell me
why would you use grease when for 10 bucks you can buy the proper stuff and do it properly......

thre is nothing wrong with at least been a little bit professional

if you really want ill go into why why grease is stupid but im sure you can figure it out for yourself......well i hope you can.....

common mate you can do better than this.....your diagnostic was good you just lacked the how to fix it part... so thats a 5/10

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Postby GT4 20 » Sun Apr 03, 2005 4:50 am

I made my comment because the noise isn't sometimes made by the pad coming into contact with the caliper. It can be made when the piston is forced onto the pad backing plate (obviously when applying the brakes) - the piston can have a tendancy to rotate slightly which results in the high pitch 'squeal'. By using either a purpose built anti squeal backing plate (usually fitted as OE) or another widely used 'fix' is to use copper ease. This 'lubricates' the contact area between the piston and pad backing thus reducing the possibility of cretaing an unwanted noise.
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Postby Perky » Sun Apr 03, 2005 1:46 pm

Well, I don't know if that is the mechanism behind the squealing -- how would anti-squeal shims stop the piston rotating? And sometimes brakes can squeal for some time -- the piston must be going crazy. But it's good to see the excitement dying down.

Obviously you want to be very careful using grease near your braking surfaces but you SHOULD put rubber grease on the sliding pins of your calipers (castor oil or silicone-based) and copper-based anti-seize grease has long been recommended as the 'proper stuff' for the backs of brake pads to prevent squealing. Since there are some mechanics here, I'm guessing that this is falling from favour with the ubiquity of shims.

I don't know what the mechanism behind the squealing is. Perhaps I read this somewhere or perhaps I just made it up but I've always assumed that the actual squeal was generated between the pad and the disc but that it was caused by the pad vibrating in the caliper (hence vibrating relative to the disc, the caliper and the piston -- so I guess it could be caused by any of these).

In any case, it can reputedly be cured by either springy anti-squeal shims, sitcky rubbery stuff or slippery copper-based grease.
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Postby Perky » Sun Apr 03, 2005 1:54 pm

I should add, for Silvergun's information, that I have used that red, rubbery CRC stuff once in the past and didn't find it wholly effective. However, it seems like it should work and others may have had success with it. Back then it was just a thick liquid and was not that easy to apply evenly. It might be better now that it's a spray. Worth trying anyway.
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Postby GT4 20 » Sun Apr 03, 2005 4:34 pm

Perky wrote:how would anti-squeal shims stop the piston rotating?


They don't. I'll be the first to admit that I don't understand it fully, but I have a feeling that it's something to do with harmonics. For example, run your finger slowly around the rim of a glass and you make a noise. Place a thin strip of metal (for eg or even copper grease) between the glass and your finger and no noise.
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