[bohunka]

Hi all

Great forum, very interesting reading, VERY helpful members!

Just curious to hear if anyone else has come across this problem:

Every time my i30 brake pedal is applied when reversing, the rear brakes emit a loud low frequency "squeal". It's really annoying, especially at night. The "squeal" has been there ever since the vehicle was purchased a couple of years ago.

The "squeal" occurs regardless of whether the brakes are hot or cold. They don't "squeal" at all in forward motion when the brakes are applied.

The rear brakes have supposedly been checked by a Hyundai dealer on two occasions. The first time they said they couldn't replicate the problem, the second time my wife collected it and was told it just needed some anti squeal spray on the rear brake rotors - YEAH RIGHT!

As soon as she brought the car home I drove it in reverse and applied the brakes, amazingly the "squeal" was still there, seemingly louder and more annoying than ever!

I put the "squeal" in inverted commas because the sound is more like the brakes on a big truck.

Thanks for reading.

[Phil №❶]

We have a 1986 "retired" Ford Meteor that does that in reverse, too. It's not a problem, just a bit annoying. However, As the brakes are disc brakes, I've heard that when racing, if the brakes are habitually run at cool temperatures, a build up can occur and this promotes "squealing". The "racing" solution to this is to heat up your brakes, but I don't advise that for normal passenger car usage. In fact, if this is happening, it is probably an indication of good brake usage.

[Surferdude]

If you are at all mechanically minded, remove the pads and run a strip of emery tape over both the pad surface and the swept rotor surfaces.

[Phil №❶]

How long will that last, Trev.

[Surferdude]

How long will that last, Trev.

Indefinitely.  But dependent probably on what the original cause is.
Used it many times over the years for exactly this issue.

[cruiserfied]

Surferdude beat me to it. Definately do that. You'll want a courser grit so it doesnt clog up. What i do it hold the emery strip on my workbench or concrete and rub the pad back and forth. That way you dont rub any low spots into the friction material. It will be a dark grey/black before and should turn a light grey once you've knocked the top off.
I will also say add a bit of a chamfer to leading and trailing edges. Nothing too much just enough so its not a 90* from rotor to pad.

[bohunka]

If you are at all mechanically minded, remove the pads and run a strip of emery tape over both the pad surface and the swept rotor surfaces.

I tried the emery fix after it came back from the dealer the first time. I thought the rotors may have been glazed but they were fine. I still gave them a rub over but it made no difference.

[Dazzler]