Brake Noise: Ferodo Pads & Zimmermann Discs Squeal?

Hello everyone!

On Saturday, I installed new, slotted Zimmermann brake discs with a diameter of 280mm on the front axle of my A3, along with Ferodo brake pads (OEM quality, so not performance brake pads).
Today, I drove approximately 150km with this setup. After a while, the familiar bite of the brakes, which I'm used to with light to moderate pedal pressure, returned, as the components had a chance to "break in" and adjust to each other.
However, I've noticed a disgusting squeaking noise in city traffic, which occurs at very low speeds and with light pedal pressure.

Now, of course, I'm wondering about the cause of this noise. My A3 is equipped with the FSIII brake system, where the pads are not glued (like in FNIII), but are clipped into the pistons and brake caliper using springs. I cleaned the pad chambers and treated the guides with a little copper paste. I also treated the contact area between the brake pistons and the back of the pads.
I very slightly rounded off the edges of the tiles with the file, but really only to the point where there were no sharp edges.

Therefore, I can't explain the cause of the squealing. Could it be that the combination of Ferodo Original brake pads and slotted rotors is unsuitable (in terms of acoustics)?

Who has advice?

Regards,
Alex.

P.S. I'm already looking forward to the first rainy drive/braking experience .

150km??? Sure.

Have you also considered properly cleaning the rotors and pads using brake cleaner/a file? The sliding surfaces of the pads and caliper should be treated with ceramic paste; copper paste has been prohibited by Audi for a long time. But we already discussed that in another thread.

My tip: Drive them in first, and then get back to me after 2000 km. And always leave the process of filing new pads to the professionals.

P.S.: I know enough Audi drivers who drive this combination quietly...

P.P.S: Just a reminder: https://community.dieselschrauber.org/en/viewtopic.php?t=8779

Hi Julian!

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150km??? Just?

Sorry, but I simply didn't drive any further today .

Quote:

Did you also think about properly cleaning the discs and pads using brake cleaner/a file? You should treat the sliding surfaces of the pads and caliper with ceramic paste; copper paste has been prohibited by Audi for a long time. But we already discussed that in another thread. icon_smile.gif

Okay, I obviously cleaned the new rotor thoroughly with brake cleaner. As mentioned above, I only slightly deburred the pads (removing sharp edges, a maximum of 0.5mm) because there were small, sand-like particles stuck to both the surface and the edges. I wanted to prevent those particles from scratching the new rotors immediately.
I am aware that Audi does not approve of using copper paste, but this doesn't bother me, as I only applied very small amounts to the sliding surfaces. From a functional point of view, copper and ceramic paste should be equivalent.

Quote:

My tip: Break them in first, and then get back to me after 2000 km.

On the first short ride on Saturday, I couldn't hear any noises yet, but I did hear them today while driving in the city .
I hope it resolves itself. The 2000km should be completed the week after next, and then I will update you here .

Regards,
Alex.

Hello everyone!

As promised, I would like to provide a brief report based on my experience.

The noise level of the Zimmermann sport brake discs combined with Ferodo pads has indeed improved within the first 2000 km. You can still sometimes hear a faint squeaking when braking very gently at walking speed, but that will probably disappear soon as well.

Otherwise, I am very satisfied with this combination. In the meantime, I also upgraded the rear axle with Zimmermänner + Ferodo brake pads, and I am more than thrilled with the improved braking performance .
Especially in wet weather, the difference in responsiveness is huge .

When I switch from my A3 back to my wife's Golf, which has the exact same FSIII brakes as the Audi, I always miss the immediate bite of the brakes.
But that will be remedied soon, because the discs and pads have already been ordered .

What I find remarkable is the fact that, especially on the rear axle, the change has led to a very noticeable increase in braking performance. Before, I could never reach the grip limit of the rear axle when braking sharply before a curve, but now you immediately notice the Electronic Brakeforce Distribution (EBD) system engaging. I used to consider the rear brakes more of a placebo, as if they weren't contributing significantly to the overall deceleration of the vehicle. Since the modification, it's very clear that a certain increase in braking power is due to the rear axle.

Initially, I struggled for a long time, wondering whether I should even undertake the renovation. Looking back, I can only say: it was the right decision!

Regards,
Alex.

That was the right decision!


Great that things are better now.

Please keep us updated on the rust behavior of the Zimmermann rotors. Many of them tend to rust very, very easily...