312mm brakes rattling

[noone]

I've had an ongoing issue since December when I bought a set of Audi TT brakes from a forum member.

The brake pads rattle when going over uneven road (so pretty often). When I apply the brakes, the noise goes away.

I've tried applying various substances to the back of the brake pads, but after some kms, the piston pushes / melts the sustance away and I'm left with the rattling.

The Pads are OEM and the inside ones have 3 little prongs to help them locate / stay connected to the piston.

So I believe the noise is the pad rattling against the Rotor or against some part of the calliper / carrier.

I'm struggling to understand why I am experiencing this issue. The callipers / carriers I bought were in reasonable condition, new pads, new rotors.

I had a look at a new set of Audi TT pads today and they had a thick almost fabric backing on the pad, mine don't have this, just a thin rubbery film which does not last long where the piston contacts the pad.

Any ideas? I don't fully understand how there is enough room for the parts to move around, hard to find good info, but from what I've read the hydrolic system should only allow very small movement between all the parts (i.e. enought to allow the pad / rotor to still touch but not enough to bounce around).

Fun Fun Fun...

[DVR68U]

hey mate do you have the little spring thing that holds the pads to stop them from rattling , sounds like that is what you are missing. ill try and get a pic , but someone might already have a pic to show you. i have the same brakes on my mk2 and i get no rattle.
cheers brenton

[noone]

A picture would be great, or an explanation. There is a metal clip on the outside that pushes the carrier and calliper appart, both sides have that.

There is a 3-prong dooby on the back of the inside pad which clips into the piston, these appear to be fine as well (and new as they come with the new pads).

[gtimonkey]

Hi noone

I run the same brake set up no problems yet. I imagine that the black rubber things in the path that allows the caliper to slide and squeeze the brakes could be worn.

It is the things either side of the pot on this pic

Google Image Result for http://img.auto555.com/photo/product/49341/big-AUDI-S3-Brake-Caliper.jpg

sorry do not have photo bucket set up.

[Yevvy]

i think someone might have not aligned the pads nicely, which caused an uneven wear and hence rattling. i had the same problem on my old subaru. the best way to fix it is to get a new set of pads (upgrade ) if you order from US, should get a set for less than $150 landed.

hope this helps

[noone]

I don't have any issues with braking, just what I believe to be the inner pad moving around when not braking.

gtimonkey: As I don't have issues with braking and the carriers slide easily on the caliper rails, not sure why this would be an issue.

Yevvy: Aligned Pads? the pads did this on day 1, the workshop was bollocks and could not work out what was making the noise and basically shrugged and said not their problem (thus never been back). I've had the pads in and out a number of times, there is not much to how they sit, its clear when they are in properly and I don't have any noise under braking or strange brake symptoms other than they move around when not braking.

Thanks for the input tho...

[goodfella]

I had exactly the same problem with my front brakes following a replacement of Rotors and Pads.... It is a solid metal knocking sound that I felt cheapened the car and made it sound like it was some cheaply designed and built <insert asian brand>!

One place did suggest it was the caliper guides, being rubber, may have deteriorated and were allowing more movement. Changed these to Tyrol brass Caliper guides but this did squat for the problem (but did improve brake feel and performance ! )

I also went with some CRC Brake Quiet goo and this did the job until the next spririted run thru the National Park! Also considered new pads, but have since persisted and after about 6 mths the knocking has greatly reduced to a knock every now and then. My only advice, keep the windows and stereo UP.

[Jmac]

Hi noone

I run the same brake set up no problems yet. I imagine that the black rubber things in the path that allows the caliper to slide and squeeze the brakes could be worn.

It is the things either side of the pot on this pic

Google Image Result for http://img.auto555.com/photo/product/49341/big-AUDI-S3-Brake-Caliper.jpg

sorry do not have photo bucket set up.

Yours were fitted with care and pride mate
Jmac

[noone]

So today I replaced the rubber calliper guides on one side (the worse side) and lubed it all up.

it SEEMS that the last buses were in pretty good condition, the biggest thing I noted was that it was very dry in there...

Before I changed over the guides, i could put my hand through the wheel and move the rear plate around with my fingers. With the new bits and lube, the movement does not seem to be there any more... Hopefully it was an issue with the install and not the parts.

As I used a little of a brake disk noise solution on the back of the pads, this may be giving me a false impression of the improvement and I may be looking at the seals / component of the piston next...

Fingers crossed.... Crossed, crossed. Crossed, crossed. - Sorry, Freddy got fingered moment

[Stuwey]

Sounds to me like you need the sprung wire clip that sits on the outer edge of the caliper that keeps preload between the two parts of the caliper.