Strange noise when slowly braking to a stop >>FIXED<<

[Xe]

I have noticed recently a strange noise when slowly braking to a stop coming from the rear of the car. Sounds a bit like when the disc brakes get all rusty after they get wet or are washed. Normally that sound disappears after the brakes are used, but this sound will not go away however much I use the breaks. I hear a "scratching sandpaper" noise kind of like SCH-sch-sch-SCH, there is a repetitive aspect to this noise, like something on the disc that keeps coming around and repeating.

However I do remember on Monday I pulled into a BP forecourt to fill up and there was a high pitched metallic screeching noise (metal on metal), I figured a stone or something had got into the brakes or somthing. So put the car into reverse, and noise stopped. Could this now low rumbling sound be connected?

I don't know what to do, is it a case of taking it back to my Seat dealer? I had the missus listen outside the car as slowly rolling to a stop using the brakes (with engine off), and she said the car was totally silent, even though I could hear the noise inside the car

 

[LeonGTI]

Hi there, the high pitch squealing is unlikely to be stone or similar as the running clearances of brakes are not huge in any way. The low rumbling sound that is similar to when rusty brakes are used after washing your car could be one of a few things

1) The nature of the friction material - some friction materials do emit a 'wire brushing' sound due to metallic content and is not a problem from a performance point - annoying though probably. Sound probably transmitted through the chassis so not easily heard from outside vehicle.

2) Problem with pads themselves, is there any damage to braking face on the disc?

3) Do you drive short, repetative journeys all the time? By braking the same way ie low speed stops repeatedly (not varied driving) can make the µ level at the friction interface increase thus can induce noise (buses for example, lots of slow speed apps of same intensity = noisy). However, I would assume that the fronts would be similarly affected.

Any of this sound familiar?

 

[Lewis_FR]

I get this noise!
As described by you, only when 1st using the brakes and at low speeds. After a while the sound is gone. I just assumed it was normal and havent done anything about it?

 

[LeonGTI]

Corrosion will build up on the discs overnight or after washing your car and is cleaned up after 1 or 2 apps. Nothing to worry about, its what the material is designed to do!

 

[Xe]

Took the car into my Seat dealer this morning, and took one of the technicians for a test drive so he could hear the noise. His opinion was that a stone etc had got in between the disc and pad.
So its booked in for Monday at a cost of £50! Said they would strip down the brakes, and would take them 1.5 hours.
He also had a quick look at the discs but couldn't see any damage, said they looked fine.
I'm going to try and powerjet the brakes and see if I can dislodge anything that maybe in there.

 

[LeonGTI]

£50!!! Thats ridiculous. It is highly unlikely that a stone will get between disc and pad as really tight running clearance and especially if no damage on disc too! I would whip the caliper off and have a look myself!

 

[chrisash32]

I have noticed recently a strange noise when slowly braking to a stop coming from the rear of the car. Sounds a bit like when the disc brakes get all rusty after they get wet or are washed. Normally that sound disappears after the brakes are used, but this sound will not go away however much I use the breaks.

However I do remember on Monday I pulled into a BP forecourt to fill up and there was a high pitched metallic screeching noise (metal on metal), I figured a stone or something had got into the brakes or somthing. So put the car into reverse, and noise stopped. Could this now low rumbling sound be connected?

I don't know what to do, is it a case of taking it back to my Seat dealer? I had the missus listen outside the car as slowly rolling to a stop using the brakes (with engine off), and she said the car was totally silent, even though I could hear the noise inside the car

My Altea has the same issue!
And likewise you cannot hear anything outside!

 

[Xe]

£50!!! Thats ridiculous. It is highly unlikely that a stone will get between disc and pad as really tight running clearance and especially if no damage on disc too! I would whip the caliper off and have a look myself!

Can you advise how to remove the caliper? What tools are needed?

 

[LeonGTI]

there are 2 parts to the caliper assembly:

1) Caliper body (part with piston in)
2) Carrier or bracket (contains guide pins and rubber boots)

You dont want to separate these really so best to undo 2 bolts that hold the caliper assy to the hub (~17-19mm bolts or maybe star drive).

This will release caliper assy from hub and can look at the unit as a whole as not to disturb pads or guide pins.

Can look at pads to see if anything lodged in - unlikely though and also check discs also for damage.

However, it is of utmost importance that the bolts are replaced from the holes they were taken from and then torqued to correct value.

 

[Deev]

I get this noise too but I thought it was related to the rumbling moaning road noise I get cos of my funked rear tyres (two new ones on Monday! Yay!)

 

[Xe]

If this is found to be something other then a stone etc, say a warped disc etc, would this be covered under warranty?

 

[LeonGTI]

If there is a genuine problem it should be covered under warranty. However, a warped disc would not produce a grinding sound but a judder that would be felt through the pedal or chassis. I'm interested to find out what it is and could probably tell in a heartbeat having seen it but harder to diagnose on a description!

Have you whipped off the caliper?

 

[Xe]

No I haven't whipped of the caliper yet as I don't have the appropriate tools. Tempted to just leave that option to the Seat dealer. However I have searched around the internet and have come across a similar post and description where a small pebble has got in between the disc and the disc guard. Which would explain the terrible screeching sound I heard last Friday. So I may take the back wheels off and have a look around plus a high powered powerjet.

 

[Xe]

OK I have whipped the back wheel off today, as I managed to pin point the noise is coming from the driver side back wheel.
Also found out that applying the hand brake gently while driving also made the exact same noise.

With the wheel off the disc and pads look like they are in perfect condition, however when I took the hand brake off, and spun the discs around I could hear something slightly rubbing (once every revolution), which sounded very familiar. Now this is as far as I was prepared to go. So this seems to me totally unrelated to any pebbles or stones. It appears to be a problem with the discs or pads themselves.

Would and should this be covered under warranty? <-- This is my main question now!

 

[Xe]

OK I have whipped the back wheel off today, as I managed to pin point the noise is coming from the driver side back wheel.
Also found out that applying the hand brake gently while driving also made the exact same noise.

With the wheel off the disc and pads look like they are in perfect condition, however when I took the hand brake off, and spun the discs around I could hear something slightly rubbing (once every revolution), which sounded very familiar. Now this is as far as I was prepared to go. So this seems to me totally unrelated to any pebbles or stones. It appears to be a problem with the discs or pads themselves.

Would and should this be covered under warranty? <-- This is my main question now!

Can anyone comment on the above, I need an answer as soon as possible, before I go bact to Seat.

 

[LeonGTI]

hi there,

it doesn't sound too serious, as there is no performance concern it doesn't sound like anything is broken!! A slight rubbing once every revolution is not unusual, there is always a slight runout on discs that may induce the rubbing sound at the high spot but once the vehicle is on the move, the movement of the suspension and subsequently the caliper will knock the pads back and thus not rub while driving. So, the noise is only under braking and on the one side?

 

[Xe]

hi there,

So, the noise is only under braking and on the one side?

Yes that is correct. Driver side back wheel. But its a horrible crusty rusty noise, that everyone can hear in the car.

 

[LeonGTI]

does it happen everytime and does it get louder when braking from higher speeds?

 

[chrisboyle999]

unfortunately i doubt itll be covered under warrenty.
it certainly sounds as though youve picked something up, be it a stone or a screw or a nail.
whatever it is is probably well embedded in to the pad by now, and dont be surprised if they try to flog you a new set of pads.
did you manage to see the back side of the disc when you had the wheel off?

 

[Xe]

does it happen everytime and does it get louder when braking from higher speeds?

No only audible at low speeds, I would say its louder when weather is dry.

did you manage to see the back side of the disc when you had the wheel off?

Yes both sides of the disc seemed fine.