Aces High Bulletin Board

General Forums => The O' Club => Topic started by: -sudz- on November 09, 2005, 09:11:09 AM

Title: brake mechanics help
Post by: -sudz- on November 09, 2005, 09:11:09 AM
I've got this problem with my brakes that's driving me up the wall - under certain temperatures and only when the dewpoint is low my brakes squeal like banshees.  They scream only the first few times I use them then they are OK.  It doesn't sound when light pressure is applied, only moderate to hard.

I've had them inspected and the mechanic said everything with them is fine.  I believe that since I'm a stickler for maintenance but he had no suggestions to stop the squealing.

I realize it probably has to do with the cold metal of the brakes condensing dew out of the air onto the discs.  There's not much I can do about that.  But are there any tricks or tips out there that can help me take care or minimize the screaming?

Thanks,
- sudz

PS  When the car was new it never did this - don't know why it started in the car's later years.
Title: brake mechanics help
Post by: AKS\/\/ulfe on November 09, 2005, 09:24:00 AM
Maybe the rotors wore funny.
-SW
Title: brake mechanics help
Post by: tce2506 on November 09, 2005, 09:36:43 AM
Did it start after a recent brake pad change?-- get better pads
Did you/they use anti squeel on the backs of the pads when they were installed? Did you/they clean all the rust off of the calipers? Check the rotors and pads for uneven wear. Lots of causes for noisy brakes, most are easy to fix. good luck
Title: brake mechanics help
Post by: airbumba on November 09, 2005, 09:55:53 AM
Isn't there that metal low pad warning piece? Maybe u need pads? Or that metal warning strip is bent outta place.
Title: brake mechanics help
Post by: MrRiplEy[H] on November 09, 2005, 10:08:29 AM
It has happened that certain brand pads produce noise on certain cars. There might be minor differences in the size etc.

Ask your mechanic to slab some anti-squeal paste (to the backside of the pad doh..) and reinstall the pads.
Title: brake mechanics help
Post by: Roscoroo on November 09, 2005, 11:48:47 AM
go back to Original pads.. some of the aftermarket pads have higher metal content that can cause the squeal your getting.
Title: brake mechanics help
Post by: dmf on November 09, 2005, 04:02:12 PM
My mechanic said to never use metalic pads, he recomends semi-metalic pads and anti-squeal on the backings of them, and he hasn't been wrong since I've been going to him.
Title: brake mechanics help
Post by: Skuzzy on November 09, 2005, 04:20:35 PM
The new ceramic pads are the best, but they are expensive.  No noise, no brake dust.  The best characteristics from metal pads combined with the quietness of the composite pads.

They last must longer than composite pads.  Did I say they were expensive?  Also, not available for every car yet.

If you are getting the squeal when pressing hard, it is not the early warning sensor of the pad.  They only make the squealing (think banshee) noise when the brakes are lightly pressed, and then they grind on hard pressure.
How long has it been since the last brake job?  Have you had to ever use the brakes for sustained periods downhill, at high speeds (>30mph)?  Some composite pads can crystallize (best word I can come up with at the moment), and they start making noise whenever they are lightly used.
Title: brake mechanics help
Post by: Torque on November 09, 2005, 04:32:22 PM
your rotors are shined , just have them turned.
Title: brake mechanics help
Post by: Skuzzy on November 09, 2005, 04:47:36 PM
You mean hot spots Torque?  Could happen if you ride the brakes a lot.  Typically they chatter though when they get like that.
Title: brake mechanics help
Post by: Bodhi on November 09, 2005, 05:59:09 PM
sudz,

Is the area of Texas you live in dusty?  If it is, you probably have the same issue that I have with mine in Colorado.  Every morning when I head out, the brakes squeal the first 3 or 4 uses.  Drove me nuts, until I figured out it was just dust settling on the rotors and the linings just scrape it of, hence the squeaking going away.

Does not happen on high humidity days at all... then go figure, the dust is that bad on those days.  

Just a part of life here on the front range of the rockies.  

If it really bothers you a lot, get the ceramic pads that the Skuzzman talks about.  I have never heard them squeal, not once, but, I can deal witha little squealing after I saw the price!!!

Good luck with it.
Title: brake mechanics help
Post by: crowMAW on November 09, 2005, 07:08:00 PM
What kind of car?  BMWs are notorious for this behavior...especially with aftermarket pads.

I agree with Roscoroo...if you are not using the OEM pads, switch back.  Many aftermarket pads squeal.
Title: brake mechanics help
Post by: Flit on November 09, 2005, 09:07:39 PM
Maybe a light coat of rust on the rotors?
 I noticed after it rains my brakes make some noise till  I "scrape them off" a bit. especially if it sits for a day or 2.
 After the first couple of uses the noise goes away.
Title: brake mechanics help
Post by: RTR on November 11, 2005, 12:44:25 PM
Turn the volume on your radio up.
This fixes most annoying sounds your car makes.

RTR
Title: brake mechanics help
Post by: Pyro on November 11, 2005, 02:16:44 PM
I had some silicone spray in my truck so I went outside and sprayed down your rotors.  That should take care of the squeak.
Title: brake mechanics help
Post by: Skuzzy on November 11, 2005, 02:17:55 PM
:rofl
Title: brake mechanics help
Post by: ROC on November 11, 2005, 02:50:45 PM
Pyro, now That's a great idea!

My Mum in Law has squeaky brakes, I'm gonna try that :aok
Title: brake mechanics help
Post by: -sudz- on November 11, 2005, 03:02:01 PM
Thanks Pyro - the squeaking is now gone.  Unfortunately I've developed a problem with my front end.  It keeps crumpling when impacting things (just stone and steel objects, mostly. Bio-mass elements just seem to slow me a little).

Thanks for the input everyone.  I think I'll check out the ceramics but may end up just gritting my teeth and bearing it.

- sudz
Title: brake mechanics help
Post by: SOB on November 11, 2005, 04:20:47 PM
Most cars and trucks have a knob on the dash to solve problems such as this.  In addition to quieting down the squeeking, and any other assorted rattles or wind noises, it will also increase the volume of your stereo.  Just keep turning the knob clockwise until you no longer hear the offending noise.

As far as the ceramic brake pads are concerned, I think cost is relative, unless I was just very lucky on price.  Shucks had ceramic pads for my heap for $55.  Which considering how long they last, seems pretty cheap to me.
Title: brake mechanics help
Post by: Skuzzy on November 11, 2005, 04:37:04 PM
Price is relative.  I was comparing the price to the current composite pads which are several 100% cheaper.
Title: brake mechanics help
Post by: SOB on November 11, 2005, 04:43:43 PM
Yeah, as I recall I had choices of quality, spaced at $10 intervals.  25, 35, 45, and finally 55.  That was for Wagoner...they probably even had super cheap crappier pads, but I've been down that path before when I was younger and (even more) dumber. :)
Title: brake mechanics help
Post by: Dowding on November 11, 2005, 05:51:21 PM
I think BMW are trying to screw me over discs and pads (I think discs are called rotors over the pond).

Anyway, the guy was trying to convince me that under new regulations pads and discs are not as durable as they once were, because they can't use asbestos. I believe the bit about asbestos, but he went on to say that they don't use as good quality steel in the discs anymore because of the change in pad composition. The upshot of all this is that he wants to charge me £180 ($300) to replace the rear discs and pads on a car thats done only 25k miles.

Front disc wear I could accept, but rear discs barely wear at all in my experience.

Think I'll buy the parts myself and get my dad to help, but has anyone heard of a downgrade in disc/rotor materials?
Title: brake mechanics help
Post by: eagl on November 11, 2005, 06:02:02 PM
Dowding,

Take a look at the rotors.  If they're deeply grooved, then they MIGHT need replacing.  Otherwise, leave them alone.

Unless you feel the car pulsing when you hit the brakes, in which case the rotors may be warped.  But rotors shouldn't warp unless you use them very hard.

As for replacing ANYTHING at 25,000 miles, that's very unusual.  I know I don't use my brakes like most people, but I get at least 70,000 miles from my brake pads.  My car has well over 100,000 miles on them and I'm just barely into my second ever set of pads.  I even raced SCCA autocross on my old pads and they lasted damn near forever.  As for my rotors, they were a little bit grooved but a turn or two on the rotor refinisher and they're almost as good as new and will probably last another 70,000 miles.

And that's a pontiac trans-am.  I can't imagine a BMW getting only 25,000 miles from a set of brake pads and rotors unless the car has been badly abused.  Ripsnort will have better info on BMWs but it sounds like the guy is trying to rip you off.  He'll probably take off your old parts and re-sell them to someone who got 100,000 miles from his brakes and is looking for a bargain that will last another 100,000 miles.

Unless something is broken, brakes shouldn't need replacing at 25,000 miles.
Title: brake mechanics help
Post by: crowMAW on November 11, 2005, 06:28:59 PM
Quote
Originally posted by Dowding
I think BMW are trying to screw me over discs and pads (I think discs are called rotors over the pond).

Sounds like BS.  I had well over 50K miles on my BMW M3 before the first time I changed the rotors (discs).  And I amature raced that car twice a month for 2 years, had a few track days and used kelated metal racing pads.
Title: brake mechanics help
Post by: Roscoroo on November 11, 2005, 11:26:24 PM
unless there pulsing pedal , come and go sqweak , wear indicators hitting . (most bmw's have elec wear sensors that set off a warning light) or the pads are down to 1/4-1/3 pad material . they dont need to be replaced yet .

if the pads are low  ,ussually a good scuff sanding of rotors/disc's is enough to toss new pads on .  (as long as the disc's are in good shape)

Bmw's like oem (original equip manufaturer) pads mostly,, there trouble free and almost never sqweek or sqweal 99%of the time.

ps, most bmw's have thick disc's and take well over 200k for then to start getting bad.
Title: brake mechanics help
Post by: Dowding on November 12, 2005, 03:13:11 AM
It's actually a BMW Mini Cooper S, but I was afraid to admit that. ;)

The brakes still feel sharp enough and there is no feedback through the pedal that would have made me think there was a problem. No squeaking either. The BMW guy reckoned that the discs were worn just below their acceptable tolerance.

Thanks for the advice, I might take it to an independant garage and ask them to take a look.
Title: brake mechanics help
Post by: Roscoroo on November 12, 2005, 09:46:06 AM
remember also alot of service shops , exsp dealers , will say your brakes are "Worn" just to sell ya the work . when  in reality they are at half life .
Title: brake mechanics help
Post by: SOB on November 12, 2005, 12:18:43 PM
Quote
Originally posted by Dowding
It's actually a BMW Mini Cooper S, but I was afraid to admit that. ;)

Man, you're as gay as Mini-D.  :p
Title: brake mechanics help
Post by: eagl on November 12, 2005, 12:23:57 PM
edit - nevermind
Title: brake mechanics help
Post by: Swoop on November 12, 2005, 12:29:56 PM
Quote
Originally posted by SOB
Man, you're as gay as Mini-D.  :p


Aw SOB, we knew that way before he bought a Mini.

(http://img.villagephotos.com/p/2002-9/48257/20029211530-0-Swoop.gif)
Title: brake mechanics help
Post by: Roscoroo on November 12, 2005, 12:33:14 PM
whats wrong with a mini coop... Ive been looking for a cheep one just to shoehorn a Rat motor / or a hemi in it... and if that doesnt work ill just gather up the squirrels and let them run .
Title: brake mechanics help
Post by: Skilless on November 12, 2005, 05:10:27 PM
It's not one of those counterfeit Minis is it?
Title: brake mechanics help
Post by: Dowding on November 13, 2005, 09:03:20 AM
The Mini Cooper S is as close to a Porsche as I'll get for quite some time. It really is an amazing drive - almost like a kart and just as much fun. Take it on twisty roads and it just shines. The supercharged engine is something else too, especially in a world of full of turbo charged engines - reminds me of a Merlin or DB. ;)

Roscoroo - I have free servicing for a couple of more years on the car. I guess they have to make their money somehow.