S7 Brake Pad Damping Plate Kit Replacement?

[hamornica]

Hi. I am a 2016 A7 owner living in Korea.
I get a lot of information about Audi from here. (But my English is not good, so I rely on translation.)
My hobby is self-maintenance, and I installed S7 brakes on my A7.
I am satisfied with the great braking performance, but there is a lot of noise and vibration when braking at high speeds.
My guess is that it is thermal deformation due to high temperature, as the discs are stained.
I replaced the discs and pads with new ones, but the same problem occurred again shortly after.
After much thought, I found a part called a damping plate that goes between the brake caliper piston and the pad.
I haven't been able to replace this part yet, but I'm wondering if this is causing the problem, so I'm leaving a post.
* My damping plate is currently covered in lithium grease and has no adhesive at all.
Brake Pad Damping Plate kit.jpg4H0698231.jpeg

[Audibot]

Not necessarily. I had a similar judder on some cars before. This has worked for me before: use sandpaper (100-200 grit) and rough up both surfaces of the discs and pads. You want to remove the pad transfer material that is on the discs. And then try to re-bed your brakes.

If you have gone so far as remove caliper, you can also see if the disc is running true and/or have a shop put it on a brake lathe to verify. Clean up excess grease because maybe the pads are sliding around.

If you do think you need the shims, the least expensive I have found (here in USA) are ÜRO PARTS 99635208602 at USD $6.97 each before tax. This is a Porsche part # (996-352-086-02). I hope you can find them pretty inexpensively yourself.

[Avantly]

Can you be more specific about the vibration? Where do you feel it from? I.e. what percentage of the vibration is felt in your hands from the wheel, vs. your feet from the floor or rear end from the seat?

Do you ever notice any shimmy, i.e. back-and-forth motion or feeling in the steering wheel at any speed at any time even when not hitting the brakes?

You can sometimes get the feeling of a warped rotor from contamination or rust on the hub - The last time you had the rotors off, did you carefully inspect the hub where the rotor seats, and make sure there was no rust/debris stuck to the face of the hub where the rotor is clamped by the force of the wheel stud? In my area, salt is a big problem, and standard procedure at all automotive shops is to take a soft grit flap disc and thoroughly clean the face of the hub before installing a new rotor - Often, a replacement rotor does not contact the hub in the exact same pattern in which the old rotor did; The areas with no contact tend to develop rust/dirt, and when a new rotor is installed, it may end up being placed over the edge of this contamination causing a very slight misalignment even when clamped by the wheel studs. Customer complaints of a warped-rotor feeling is extremely common due to even small amounts of rust on the face of the hub, so this cleaning procedure is critical for us in the rust belt :-)

[hamornica]

Not necessarily. I had a similar judder on some cars before. This has worked for me before: use sandpaper (100-200 grit) and rough up both surfaces of the discs and pads. You want to remove the pad transfer material that is on the discs. And then try to re-bed your brakes.

If you have gone so far as remove caliper, you can also see if the disc is running true and/or have a shop put it on a brake lathe to verify. Clean up excess grease because maybe the pads are sliding around.

If you do think you need the shims, the least expensive I have found (here in USA) are ÜRO PARTS 99635208602 at USD $6.97 each before tax. This is a Porsche part # (996-352-086-02). I hope you can find them pretty inexpensively yourself.

Thanks for the reply.
I'll have to go to the mechanic and get the discs polished.
This part is very expensive in Korea. I think a set of 12 is over $300 at the Audi service center.
I'll have to look for after parts on eBay or Amazon that ship internationally.
$6.97 each. I'm jealous of that low price!!!

[hamornica]

Can you be more specific about the vibration? Where do you feel it from? I.e. what percentage of the vibration is felt in your hands from the wheel, vs. your feet from the floor or rear end from the seat?

Do you ever notice any shimmy, i.e. back-and-forth motion or feeling in the steering wheel at any speed at any time even when not hitting the brakes?

You can sometimes get the feeling of a warped rotor from contamination or rust on the hub - The last time you had the rotors off, did you carefully inspect the hub where the rotor seats, and make sure there was no rust/debris stuck to the face of the hub where the rotor is clamped by the force of the wheel stud? In my area, salt is a big problem, and standard procedure at all automotive shops is to take a soft grit flap disc and thoroughly clean the face of the hub before installing a new rotor - Often, a replacement rotor does not contact the hub in the exact same pattern in which the old rotor did; The areas with no contact tend to develop rust/dirt, and when a new rotor is installed, it may end up being placed over the edge of this contamination causing a very slight misalignment even when clamped by the wheel studs. Customer complaints of a warped-rotor feeling is extremely common due to even small amounts of rust on the face of the hub, so this cleaning procedure is critical for us in the rust belt :-)

Should I film a video and upload it?
There is a very loud noise that howling the car during high-speed braking, and an unpleasant vibration that can be felt when riding the steering wheel.
here is no particular problem with the floor or the rear. As far as I know, if there is a problem with the rear brake disc, the symptoms are worse than the front disc.
Before installing, I removed the rotor, removed all the rust that had formed inside the hub with a metal brush, and applied lithium grease that can be used even at high temperatures and installed it.
The only other suspicious thing is that the appropriate torque was not used when tightening the caliper and disc.
I need to visit a repair shop and get a professional diagnosis, but I think it's a priority to replace all the consumables.
I've already spent too much money replacing the discs and pads twice. T^T

[Avantly]

Should I film a video and upload it?
There is a very loud noise that howling the car during high-speed braking, and an unpleasant vibration that can be felt when riding the steering wheel.
here is no particular problem with the floor or the rear. As far as I know, if there is a problem with the rear brake disc, the symptoms are worse than the front disc.
Before installing, I removed the rotor, removed all the rust that had formed inside the hub with a metal brush, and applied lithium grease that can be used even at high temperatures and installed it.
The only other suspicious thing is that the appropriate torque was not used when tightening the caliper and disc.
I need to visit a repair shop and get a professional diagnosis, but I think it's a priority to replace all the consumables.
I've already spent too much money replacing the discs and pads twice. T^T

Is it loud enough that you can actually capture it with a phone microphone?
Every time I've been in Korea it seems that the roads were in excellent condition, so we definitely can not blame the pavement xD

What type of brake disc and pad did you use? OEM? If not OEM, are they drilled or slotted?
Is the noise ever present when you are not applying the brakes? If "yes", does the noise change at all if you sway to the right or left, with no brake applied, such that the vehicle's weight is shifted to the left or right?
Has the brake fluid been bled during any of the brake services?

[hamornica]

Is it loud enough that you can actually capture it with a phone microphone?
Every time I've been in Korea it seems that the roads were in excellent condition, so we definitely can not blame the pavement xD

What type of brake disc and pad did you use? OEM? If not OEM, are they drilled or slotted?
Is the noise ever present when you are not applying the brakes? If "yes", does the noise change at all if you sway to the right or left, with no brake applied, such that the vehicle's weight is shifted to the left or right?
Has the brake fluid been bled during any of the brake services?

If my wife is riding next to me, she will be startled by the sound and very anxious.
As you said, the road surface is smooth, so there is no problem at all.
The disc is a Zimmerman product, and slots are machined for gas and heat dissipation, and holes are not made because they seem to be bad for durability.
There is a unique noise when it reaches perfect braking, but I can clearly distinguish it.
The first pad was a Brembo ceramic pad, but I have now changed it to a TRW COTAC pad, but the symptoms are all the same.
It is so sad that this is happening even though all the parts used are Audi Original Equipment Supplier parts(OES).
And check the moisture level of the brake fluid every time the season changes and replace it with a new one.
Lastly, if the symptom persists even after resurfacing the disc and replacing the damping plate, I will probably have to use the genuine Audi parts.
I used to buy parts locally for quicker maintenance even if it cost a little more, but now I'm looking hard for Rock Auto to reduce my expenses.
Thank you for your answer. ;)

[Avantly]

Interesting that you used Zimmerman rotors. I was told that these should be good quality rotors, and put a set on one of my C5 allroads. Within a few weeks I had vibration issues while braking which became severe after a few months and I purchased different rotors. It appeared that the rotors had a "hard" spot which was wearing differently and this created quite an unpleasant braking experience in that allroad.

This happened to me almost 4 years ago, I wonder if there is still an issue with Zimmerman rotors? I don't know much about their quality, but I replaced them with a different brand (I think it was Bosch) and had no more problems.

I also use Rock Auto, and FCP Euro for nearly all of my parts needs. I also use ShopDAP aka Deutsch Auto Parts especially when I need specific VAG fasteners, as they seem to list every single VAG fastener in existence.

Anyway, I would remove the rotors and take a good look at the friction surfaces. When I had the hart spot issue on my zimmerman rotors, it became visible - I don't recall exactly what it looked like but it seems that there was a spot a few inches wide with a visually different appearance than most of the friction surface. If there is a significant hart spot, it may be a problem for resurfacing, I am not sure. Also, as with any slotted or drilled rotor, always good to inspect closely for any cracks during service.

Also, FYI, I have used slotted rotors, but on the centric slotted rotors I used, there was some significant humming during hard braking. It was not alarming, but was definitely noticeable from both sound and feel. I think that the slots are not causing your issue, though they may be adding to the noise a little bit.

[Audibot]

Interesting that you used Zimmerman rotors. I was told that these should be good quality rotors, and put a set on one of my C5 allroads. Within a few weeks I had vibration issues while braking which became severe after a few months and I purchased different rotors. It appeared that the rotors had a "hard" spot which was wearing differently and this created quite an unpleasant braking experience in that allroad.

This happened to me almost 4 years ago, I wonder if there is still an issue with Zimmerman rotors? I don't know much about their quality, but I replaced them with a different brand (I think it was Bosch) and had no more problems.

On my RS, I replaced with Zimmermann and after a group driving trip in the mountains, they juddered like crazy when they were roasting hot. Thankfully I bought via FCP, who accepted my return. Second set has been perfectly fine. Did the same trip and no issues whatsoever.

You could have gotten a bad batch, but that's all it takes to shape your experience. Same reason I won't get one of those clay detailing pads. First one left orange peel in my paint that I had to later polish out. So I'll stick to traditional clay.

[Avantly]

On my RS, I replaced with Zimmermann and after a group driving trip in the mountains, they juddered like crazy when they were roasting hot. Thankfully I bought via FCP, who accepted my return. Second set has been perfectly fine. Did the same trip and no issues whatsoever.

You could have gotten a bad batch, but that's all it takes to shape your experience. Same reason I won't get one of those clay detailing pads. First one left orange peel in my paint that I had to later polish out. So I'll stick to traditional clay.

Agreed, I'd definitely give them a chance again, but I always buy the plated rotors due to salt belt and rock auto always seems to have the best price by far (and they don't sell zimmerman). Does Zimmerman make 2-piece rotors for the C7 like OEM? It seems that back when I purchased rotors for my S6 the only OEM style option was VNE, but that was years ago.

[Audibot]

Probably still single piece. OE SHW would be the way to go.