My brakes . . . .

23-05-2003

HELP - changed pads and discs so much recently to stop a high pitched squeeking noise (some of you may have read my previous posts)but it has all been to no avail - its not like normal brake squeel it is like dragging your nails down a chalkboard but a metal version - was told that it had to be the pads or discs so changed both for OEM Alfa ones - now the noise is back - doing my head in, it only happens at slow speeds though and as I am just about to stop from any reasonable speed - could it be the piston stcking - or dirt inside possibly - Im not **** hot on brakes but I need to know anything and everything that could cause weird noises other than the pads or discs!!!! also - the brake pedal feels funny - it is a bit harder than normal but the bite is further down the pedal????? Thankyou so much for your help in advance.
SW

jomor · 23-05-2003

Stewright, if you changed recently the pads, its normal to feel different. After 500 kms it will feel much better. About the noise. I changed my pads recently, and I also have a noise which seems like a bad opera loud voice

Its the pads-disk combination, I hate it and i dont know if some rubbing at the pad's edges could help. I will try that, otherwise I will change them again because it p*sses me off. I dont think its a matter of cleaning, it happened to me just after the new pads, it happens less times lately.

23-05-2003

Jomor - thanks for this - let me know how you get on.

Banflu · 23-05-2003

jomor when i bought the mmintex pads the salesman gave me a sticker-like material (its like self-adhesive tar, sort of) really thick material.

he said to cut it in the pad's shape and stick it to the backside of the pad, so they wont squeal. i already did that and will install them soon... i hope.

will tell you hhow it goes..

alibob · 23-05-2003

Hiya
An old trick used to be to put a VERY LIGHT SMEAR of Copperslip grease on the back of the pads.
Alibob

jomor · 23-05-2003

http://www.alfaowner.com/forum/ubb/icons/icon01.gif

Let me get this right... you mean that the squeal comes from the rear part of the pad? From the metal surface that touches the caliper??

I thought it was from the material touching the disks

Banflu · 23-05-2003

well, i dont know

thats what he said though

jomor · 23-05-2003

<blockquote>quote:<hr />Originally posted by Banflu:
jomor when i bought the mmintex pads the salesman gave me a sticker-like material (its like self-adhesive tar, sort of) really thick material.

he said to cut it in the pad's shape and stick it to the backside of the pad, so they wont squeal. i already did that and will install them soon... <hr /></blockquote>..can I have the leftovers ???

23-05-2003

Copperslip should do the trick and the 156 inside brake pad has a 3 prong retainer so be sure to put a dab on that as well. be sure not to get any on the pad lining.
by the way are you aware of regulation 90.
that is all brake pads have to be E marked or you may fail your M.O.T.
This only applys to cars registered after 99.or V reg.

p.s.
did you cheak your new disks for run-out.

AlfaAlfa · 23-05-2003

Two reasons for squeal:
Pads moving in their seating or pads moving in their seating...
1. Try to get 3M material to stick to the back of the pads. This stuff is heat tolerable and will "glue" the pads to the piston to avoid the pads moving.
2. Try to make a slanting edge on the side of the brake material on the pads that first come into contact with the disc. This reduces the possibility of movement.
3. Copperpaste on the metal back(!) and metal sides of the pads to grease any movement between pads and caliper to avoid the movement to become hearable noise.

If you need comforting then test or buy a Porsche or Ferrari and then you will get to know what brake squeal is all about!

Banflu · 23-05-2003

<blockquote>quote:<hr />Originally posted by jomor:
..can I have the leftovers ???

<hr /></blockquote>NO!

LoL, seriously, i cant cause i dont have enough leftovers for a whole set.
but if you go to someone who sells pads, he should have such material i think?
or use copper grease, like the guys are saying.

jomor · 23-05-2003

<blockquote>quote:<hr />Originally posted by Banflu:
 <blockquote>quote:<hr />Originally posted by jomor:
..can I have the leftovers ???

<hr /></blockquote>NO!

.<hr /></blockquote>I was just kidding Pat

23-05-2003

so let me get this right - the only thing that can realistically cause squeel is the pad in its seating vibrating - that sounds reasonable - is it worth copper greasing the prongs that sit inside the piston??? when you are talking about the sticky pad that sticks it in place - the outside pad came with that (on ferodo pads from alfa) but the inside pad just sits in place with the prongs inside the piston!!!!. . . . . .could the prongs be vibrating inside the piston ??????

jomor · 23-05-2003

<blockquote>quote:<hr />Originally posted by AlfaAlfa:

2. Try to make a slanting edge on the side of the brake material on the pads that first come into contact with the disc. This reduces the possibility of movement.
3. Copperpaste on the metal back(!) and metal sides of the pads to grease any movement between pads and caliper to avoid the movement to become hearable noise.
<hr /></blockquote>2: this is already done

3: greasing makes sense, but with the first rain(I know its not water soluted but..) or the strong heat, wont the grease slide down and reach maybe the disks http://www.alfaowner.com/forum/ubb/icons/icon02.gif

Banflu · 23-05-2003

LoL! jomor dont worry i was kidding as well, duh!

i got them for free anyway wink

btw, if you use a high temperature grease (like the Omega copper grease) i'm sure it will not dissolve or anything

23-05-2003

so let me get this right - the only thing that can realistically cause squeel is the pad in its seating vibrating - that sounds reasonable - is it worth copper greasing the prongs that sit inside the piston??? when you are talking about the sticky pad that sticks it in place - the outside pad came with that (on ferodo pads from alfa) but the inside pad just sits in place with the prongs inside the piston!!!!. . . . . .could the prongs be vibrating inside the piston ?????? will it cause damage by putting grease inside the piston ??

Banflu · 23-05-2003

no it shouldnt harm anything AFAIK

RicksAlfas · 23-05-2003

<blockquote>quote:<hr />Originally posted by Banflu:
no it shouldnt harm anything AFAIK<hr /></blockquote>Just slather it around, but make sure it is proper copper brake grease.
I've never changed pads on an Alfa - do they have anti rattle shims behind them??
Like bits of pressed tin about the size of the pad?? They mustn't be left about!!
http://webcentrix.net/probe/service/images/h6062-b.gif

AlfaAlfa · 23-05-2003

Hi again,
the pads with the sprong could probably do with some sticky 3M pads to make it stick. One set of Ferodo original pads had some also on the inside pads (the ones with the sprongs).
The sound is not from the sprongs moving inside the piston and I woudnt bother having copper paste inside the psiton. Its the pads moving/vibrating against the caliper. So any contactpoints between caliper and pads could need a little copper paste, but I would recommend the adhesive 3M because they take the movement away.
Also because although the copper paste is resistant to heat and water its still a grease and its close to friction area which is a no-no. So adhesive and file off some of the friction material to make it slightly inclined I think is the best idea.
rgds
AlfaAlfa