Braking Noise: Why Your Disc Brakes Squeak

Hello,

"For the past few days, I've been hearing a brief crackling sound in my Ibza 6L Cupra whenever the rear brakes are engaged, whether it's through the foot brake or the handbrake."
Otherwise, the brakes and braking performance feel completely normal, and the rotors appear to be in good condition when viewed through the rims.
I'd like to go and take a look if the weather is good.

If this crackling sound is a common problem, any tips on the cause(s) would be greatly appreciated.

Thank you.
Best regards.

Ulf.

Hello Ulf,

First, check the banjo bolts (fittings) of the brake calipers. It's also possible that the brake pads have some play within the calipers.

Best regards, Rainer.

Hi Rainer,

I checked, and everything seems normal.
However, I can probably trigger the creaking sound by moving the left handbrake lever. But it only creaks after a few minutes of inactivity, and then only noticeably with the first movement. After that, it quickly becomes quieter and disappears completely after the fourth attempt.
Since the crackling sound (after the mentioned pauses) can also be triggered by the foot brake, I assume it originates from the movement of the pistons.

"Funny thing... I regularly engage the handbrakes on our cars, and they seem to be pressing against rusty rotors. The braking force feels completely normal. The free play on both handbrake levers (until the pads engage) is the same. Also, the left brake isn't sticking, and the wheel spins freely."

I'll keep an eye on it for now.

Resolution:
On the left wheel, the brake pads were so tightly fitted against the caliper (despite the presence of shims between the pads and the caliper bracket) due to rust formation on the bracket, that even the slightest movement of the pads caused creaking and squealing noises.

The tiles were removed (or knocked out), rust was filed away, all seating surfaces were lubricated with copper paste, it was assembled, and it's been quiet ever since.

(During the process, the Ibiza incidentally showed me the next construction site: underbody corrosion in several places . See https://community.dieselschrauber.org/en/viewtopic.php?t=8251).

It's not going to be boring. It's good that the issue with the } surface was noticed before it and the } disc were damaged.

I wouldn't use copper paste in this case, but rather aluminum paste. Based on my experience, the effect of copper paste doesn't last long enough.
Somewhere during my technical training, I overheard that the copper layer attacks the weaker metal, but I didn't pay much attention to the details at the time due to a lack of interest. "I'm such an idiot."

http://www.feuerverzinken.com/wissen/arbeitshilfen/arbeitsblaetter/e-weiterverarbeitung/e5-kontaktkorrosion/

Copper paste is acceptable for use on iron parts, but it can be problematic for aluminum; in that case, use ceramic paste instead.

Best regards, Rainer.