Squealing brakes

hawker

I have a bit of a problem with squealing brakes on my Peugeot 407 1.6hdi. Is this normal with this model? Have I anything to be worried about?

daedalus2097

All brakes will squeal under certain curcumstances... Chances are they're fine but if you get new pads put on the front it will more than likely get rid of it. If it's an actual squeal and not a scrape of metal on metal the pads have probably gone off from being contaminated or overheated... How long are they on the car?

hawker

daedalus2097 wrote:

All brakes will squeal under certain curcumstances... Chances are they're fine but if you get new pads put on the front it will more than likely get rid of it. If it's an actual squeal and not a scrape of metal on metal the pads have probably gone off from being contaminated or overheated... How long are they on the car?

It's an 05 (October) and they were on it when I bought it. There is now 40k on the clock. It seems to be a squealing rather that metal on metal.

C_Breeze

more than likely you need new brake pads.

Check your manual and see if worn brake pads should bring up a light in your dash, also if you have alloys you should be easily able to see what state the pads are in.

Henry Ford III

Copper grease, applied in the correct places, will cure this issue, assuming the pads are not worn out in the 1st place.

Stephen

Brake pads are designed to squeal when they get worn down past a certain point, in order to compel the driver to get them replaced before they get so worn that you end up damaging your discs!

daedalus2097

I've come across and replaced lots of brake pads which have been less than half way through their life but are squealing away something serious - in most of these cases the friction surface of the pads has become "glazed", looking shiny instead of dull matte, and this is usually due to overheating or similar abuse. If their cheaper pads this will happen more easily, there might niot be anything you can do to prevent it if that's the case. I'd get them replaced with a decent set and you'll be grand.

@Stephen
On the other hand, that's hardly a reliable indicator, I don't remember having a set of pads that did that, and I've chewed my way through many You sure it's not just the cumulative effect of heating which happens to coincide with when they need changing?

@C_Breeze
It would be best to take the wheel off and look through the caliper as often the inside pad wears quicker than the outside. There's usually a rectangular area at on the side of the caliper where you can see through to the edge of the disc and the pads on either side. Might be worth having a quick look there to see what thickness they are on both sides...

MercMad

No pads are designed to squeal at any point !

I would suggest you have you pads and discs inspected by a mechanic you trust !

Darragh29

Stephen wrote:

Brake pads are designed to squeal when they get worn down past a certain point, in order to compel the driver to get them replaced before they get so worn that you end up damaging your discs!

That's news to me!

Moanin

I had the same problem on my previous car Peugeot 307 and replaced discs and pads numerous times and they still squeal the odd time .It seems to be a common thing on peugeots

_Kaiser_

My Passat is doing the same the last week or two. Had it checked out by the guy I bought it from (was up with him for something else) and he says the pads are low alright, but I should be ok till the next service (about 2.5/3k away).

Seems a bit long to wait to me? (especially given the 250-300 miles I do every week). Should I go get them done now, and how much would I be expecting to pay?

daedalus2097

It's hard to say whether you should get them done straight away or not without seeing them, but they don't fail all of a sudden so if you wanted to leave them until the serfice you should be ok, if you get the scraping sound or low pads indicator on the dash before the service, get them done then. But for peace of mind you can get them done fairly quickly (less than an hour), not sure what they'd cost for a Passat but most cars would be under €100 for the pads themselves and labour.

_Kaiser_

daedalus2097 wrote:

It's hard to say whether you should get them done straight away or not without seeing them, but they don't fail all of a sudden so if you wanted to leave them until the serfice you should be ok, if you get the scraping sound or low pads indicator on the dash before the service, get them done then. But for peace of mind you can get them done fairly quickly (less than an hour), not sure what they'd cost for a Passat but most cars would be under €100 for the pads themselves and labour.

That's not too bad I suppose. Would I need to go to a mechanic, or is it something the tyre places can handle for example.

As far as dash warnings go, she's given a very overly-dramatic "STOP BRAKE FAULT" warning and beeping a few times in the past 2 weeks, but it only lasts a few seconds and naturally the brakes actually still work

hawker

Thanks for the replies people. I'll be getting the car serviced pretty soon so I'll get them checked out then.

I thought I read somewhere else where a person with a Peugeot had the same problem with their brakes.

daedalus2097

Kaiser2000 wrote:

That's not too bad I suppose. Would I need to go to a mechanic, or is it something the tyre places can handle for example.

As far as dash warnings go, she's given a very overly-dramatic "STOP BRAKE FAULT" warning and beeping a few times in the past 2 weeks, but it only lasts a few seconds and naturally the brakes actually still work

Yeah, that's probably the wear sensor showing up. Pads with the sensor are usually a few quid more expensive but not much. Most of the bigger tyre places should be able to do it - just give them a ring beforehand to make sure. Failing that any mechanic should be able to find an hour somewhere to fit you in...

CJhaughey

MercMad wrote:

No pads are designed to squeal at any point !

I would suggest you have you pads and discs inspected by a mechanic you trust !

I think you are being pedantic, maybe they don't squeal but they make a horrible screeching/scraping noise when almost worn out .
Most pads have a small metal tab that will contact the disc surface when the pads approach end of life, the result is a horrible sound that may be construed as a squeal or a scrape depending on how the pad is set up.

MercMad

As far as dash warnings go, she's given a very overly-dramatic "STOP BRAKE FAULT" warning and beeping a few times in the past 2 weeks, but it only lasts a few seconds and naturally the brakes actually still work

........so why didn't you stop and get them checked ?? BTW yellow/orange lights usually mean you need to make an appointment to get something checked out, red lights mean "Stop" and get it checked immediately !

I think you are being pedantic, maybe they don't squeal but they make a horrible screeching/scraping noise when almost worn out .
Most pads have a small metal tab that will contact the disc surface when the pads approach end of life, the result is a horrible sound that may be construed as a squeal or a scrape depending on how the pad is set up.

.......I am not being pedantic at all. i have changed brake pads for a living on any type of car you cvare to mention and I can tell you I have never seen any that had a metal tab designed to make contact with the disc and cause a screeching noise. I have of course seen the sensor wire/contact, but this is different to what you seem to be suggesting. Also sensor wires are sometimes only fitted to one pad on the front, the other three can in fact wear prematurely, so lights on dashes should not be relied upon, regular servicing should be part of car ownership.

Anyway, we've been here before with that point, you made that comment before in another thread and I believe it was disputed aswell !

Screeching sounds are caused by vibrations, either the pad is worn, glazed, hardened through heat or is worn out with the backing plate grinding. Other than that you could have any or the above together with worn discs where the pad backing it touching the edge of the discs, despite there still being some friction material left.

Poor quality pads can cause it as can the lack of backing shims or copper grease !

To the OP and anyone else, if you have never fitted pads before then dont DIY. By all means go and watch someone do it or get someone how has done it to stand over you. Its not hard, just important that its done right, and always remember to pump the pedal before you move off !

daedalus2097

MercMad wrote:

.......I am not being pedantic at all. i have changed brake pads for a living on any type of car you cvare to mention and I can tell you I have never seen any that had a metal tab designed to make contact with the disc and cause a screeching noise.

I changed a set on a 00 Punto last year and it had soemthing like this. Admittedly I've only seen it the one time, but the pad itself still had 4mm or so left at their narrowest spot so they weren't worn through. It was just a small flap of metal out of part of the backing of the pad. Not big enough to cause noticeable damage to the disc but it made a horrible noise!

and always remember to pump the pedal before you move off !

Hehe, you'll only make that mistake once

MercMad

Hehe, you'll only make that mistake once

......Ohh yes !!

As I said I have never seen that before, but I apologise to CJ and yourself if I appeared too matter of fact ! You learn something new every day !

Stephen

MercMad wrote:

No pads are designed to squeal at any point !

I would suggest you have you pads and discs inspected by a mechanic you trust !

I was told this by a mechanic when I had the pads replaced on my old car! Perhaps he was filling me with bull5hit.

CJhaughey

[QUOTE=MercMad



.......I am not being pedantic at all. i have changed brake pads for a living on any type of car you cvare to mention [/B]and I can tell you I have never seen any that had a metal tab designed to make contact with the disc and cause a screeching noise. I have of course seen the sensor wire/contact, but this is different to what you seem to be suggesting.

Anyway, we've been here before with that point, you made that comment before in another thread and I believe it was disputed aswell ![/QUOTE]

Screeching sounds are caused by vibrations, either the pad is worn, glazed, hardened through heat or is worn out with the backing plate grinding. Other than that you could have any or the above together with worn discs where the pad backing it touching the edge of the discs, despite there still being some friction material left.

[/QUOTE]
So have you ever changed pads on a Toyota or Lexus?
Because page 7 of this http://www.autoshop101.com/forms/brake04.pdf describes what I am explaining to you.
Of course If I am wrong then I humbly apologise to your superior knowedge...:D

Automan

Any break pads I have ever changed have had these wear indicators but they were all pre 00 Hondas and Nissans.

Link:

http://auto.howstuffworks.com/disc-brake4.htm

It could also be a Seized Caliper making the squealing noise.

MercMad

So have you ever changed pads on a Toyota or Lexus?
Because page 7 of this http://www.autoshop101.com/forms/brake04.pdf describes what I am explaining to you.
Of course If I am wrong then I humbly apologise to your superior knowedge...

.........no, no, its my turn to eat the humble pie here !!

I looked at that article, and yes I have changed Lexus pads, a long time ago. I have never come across those type of wear indicators, and it looks to be a stupid idea. Why not just have them switch on a light on the dash ? It seems odd that they let metal contact the discs !

Anyway, I learned something new, "Every day is a schoolday "

CJhaughey

The indicators are only a very small piece of folded steel, 2mm in thickness they would take an awfully long time to do anything to a disc.
I guess the thinking is that the noise will drive you mad before the pads wear out completely, they are probably a KISS idea, instead of relying on the vagaries of electrical power down near where roadsalt/water/grit etc is they just make a noise and prompt you to get the brakes looked at.

cpoh1

My pads squeal to bejesus after a spirited drive when they are well warmed up. Mintex say its a characteristic of their full race pads that they squeal when warm and that its nothing to worry about.

MercMad

CJhaughey wrote:

The indicators are only a very small piece of folded steel, 2mm in thickness they would take an awfully long time to do anything to a disc.
I guess the thinking is that the noise will drive you mad before the pads wear out completely, they are probably a KISS idea, instead of relying on the vagaries of electrical power down near where roadsalt/water/grit etc is they just make a noise and prompt you to get the brakes looked at.

....ahh yeah the metal is pretty soft so it wouldn't really score the disc, just make a nasty scraping sound !

My pads squeal to bejesus after a spirited drive when they are well warmed up. Mintex say its a characteristic of their full race pads that they squeal when warm and that its nothing to worry about.

......yeah I used to use M171's then M1144's on my cars in the past. The 171's were really poor until they warmed up, first application in the morning you would swear it wasn't going to stop ! Mine never squealed though, but it was a light car........I do recall a lot of Cosworths and the like that squealed like crazy when hot !

cpoh1

MercMad wrote:

......yeah I used to use M171's then M1144's on my cars in the past. The 171's were really poor until they warmed up, first application in the morning you would swear it wasn't going to stop ! Mine never squealed though, but it was a light car........I do recall a lot of Cosworths and the like that squealed like crazy when hot !

Ive got a set of M1155's on the front at the moment and it takes a good 5 mins of solid braking before they come anywhere near their potential. It can be a bit of a pain but I only take my car out at the weekends anyway so its not as much of an issue as it would be with a daily driver.

sundodger5

Stephen wrote:

Brake pads are designed to squeal when they get worn down past a certain point, in order to compel the driver to get them replaced before they get so worn that you end up damaging your discs!

In fairness the pads themselves are not designed to squeal but on a some models the "wear indicator" is a piece of thin metal set to the wear limit.
pads at limit piece of metal touches brake disc causing the squeal.
sorry beaten to the point above...