Noisy brakes when reversing

[sanddancer55]

Just bought a new 1.4TFSi Q2 and its done 1000 miles in the 10 weeks I've had it. Its developed a braking noise when reversing. Sounds like elephant trumpeting. I took into the dealership and they power washed the discs but to no avail. Last week it went into the garage for the day and they said the problem was " normal and caused when the static friction is bigger than the dynamic friction which causes the noise." The noise is very loud and turns heads. I've had a lot of new cars over the years, 6 Audis and none have made this noise. Has anyone else had a similar problem and was it fixed?

[Magnet]

Hello Hazel,

Well, ..." static friction is bigger than the dynamic friction..." I really like that!  For friction please leave the 'r' out and subsititue ''fiction' .

This car is trying to tell you something, and you are right to be concerned that it isn't as it should be. Apart from the above!? , there could be a number of valid reasons. 

Could you report back on the effects on the noise of the following:-

When reversing and the noise is present, gently (in caps) apply the handbrake to one or two notches.

When reversing and the noise is present, turn the steering wheel slightly from side to side. Probably daft and unnecessary to advise only going this when there is plenty of room around you and it's safe to do so. 

Kind regards,

Gareth.

[sanddancer55]

Thanks Gareth but I don't have a manual handbrake its electronic. I have tried the thing with the steering and it did stop the noise but not sure if it was a coincidence. I am not happy with explanation as I feel i'm being fobbed off. I have only just done 1000 miles and wondered if it was just the brakes bedding in but I will pursue my questions with the dealership. Cheers Hazel

[Magnet]

Hello Hazel,

Silly me - electronic handbrake! 

If noise alters when the steering turns then there is a stronger possibility that the noise originates from the front wheels rather than the back. 

Can we take it you don't get any noise when moving forward slowly? 

Sorry about additional questions, but full information is king:- 

During your two and a half months of ownership, how often has the car been washed, and what method has been used to clean it? 

Kind regards,

Gareth. 

[sanddancer55]

Hi Gareth,  I've had quite a few days without incident, until today! The noise is back. I still only hear it when I am reversing and usually when I am going up over the dropped kerb. I am seriously thinking of taking it to another Audi dealership and see if they concur with their colleagues. I will let you know if I get any joy. Thanks for your info. Cheers Hazel

[Magnet]

Thanks for coming back Hazel.

You didn't tell us how the car is washed.

It may be thought to be a daft question, but.... 

Kind regards,

Gareth. 

[sanddancer55]

14 minutes ago, sanddancer55 said:

Hi Gareth,  I've had quite a few days without incident, until today! The noise is back. I still only hear it when I am reversing and usually when I am going up over the dropped kerb. I am seriously thinking of taking it to another Audi dealership and see if they concur with their colleagues. I will let you know if I get any joy. Thanks for your info. Cheers Hazel

Sorry I thought I had replied. The car has only been washed a couple of times using a bucket and sponge. The dealership did however jet wash the discs when I first went in to have the car checked and they washed the car the after the second visit ( left the car in an awful state as they didn't rinse or dry the car and my husband had to wash it again to get rid of the marks.) I assume it was jet washed by dealership then using a bucket, sponge and wash leather by my husband.

I had hoped someone else had experienced a similar problem and it had been fixed.

Cheers Hazel

[Magnet]

Thanks Hazel,

OK, bucket and sponge.

 Bang goes my theory of acid contamination of the discs/pads then - unless hubby uses spray-on wheel cleaner when he washes it. 

If it were mine, I think I would insist on having new pads fitted, and the discs thoroughly cleaned up. Chances of getting Audi to do that under warranty??

Kind regards,

Gareth.

[andy.h]

Hi Hazel.

I hope you have got the problem sorted out by now but this could be what was causing it.

I have seen this problem with motorbikes and it's been down to either the way the pads are setup or the way the pads have worn, obviously not reversing but just pushing the bike backwards..

The problem was basically that the back of the pads friction material was slightly closer to the disc than the front which is ok when your moving forwards arguably actually better but the problem is when your reversing the front of the pad friction material (actually it's the back of the pad but your reversing) is closer to the disc first which can cause a screeching noise, this happens because when your not braking the pads are very lightly touching the disc and because it's the front face of the pad touching the disc it causes a vibration.

Putting grease between the piston and pad can help the problem but obviously thats not helped you so i would ask for the dealer to remove the pads and check the making sure they have not worn unevenly.

If you put your foot lightly on the brake the noise will go away.

 

Andy

 

[sanddancer55]

Thanks Andy  I have had the car fixed. The brake pads had been replaced but the problem remained. So Audi Germany listened to the audi tape I made of the noise and after 2 weeks of trying various remedies they replaced the pads with "different " pads and it seem to have sorted the problem. I got the car back after 2 weeks just in time for Christmas. So far no further problems. Thanks for your efforts though, much appreciated.

[andy.h]

Hi Hazel, thats great, as long as it's fixed now.

Andy

[Steve Q]

Glad it's resolved 🙂

[Fvvc94]

I’m having the same problem. Audi says it’s nothing to worry about but it is clearly not normal. 

[andy.h]

Hi,

Since my last post, for a short while my rear brakes started making the noise, for some reason it seems to have sorted itself. I noticed in another forum that due to the same problem some Audi dealers had changed the rear brake pads which had resolved the problem. I think they said the new pads had a different friction material.

[Jaywak]

Had the same problem on my 21 VW T roc , it was a known problem and called the mooing brake problem VW changed the rear brake pads with a different type and the problem was solved .