Fixing Brake Squeal
 

I have a 2010 220 CDI 4matic and around 2012 the brakes starting squealing under soft braking so I took it in under warranty and it was fixed. The service center told me to expect it to come back after awhile.

When it started getting really cold here this year it started again. I've read here and other sites that if you brake hard a few times it should go away. I've tried that near my house on a downhill incline before heading to work but I was only going around 40 km/h and broke hard a few times (ABS also kicked in). It seemed to do the job but the squeal always comes back later at night.

My car is kept in a garage overnight but outside under covered parking at the office. Does the cold have anything to do with it?

Since I'm in Seoul, there's not a lot of places where I can go 100 and brake hard without putting myself and others in danger. Is this the trick to make the annoying squeal go away? I got new tires in August and when I brought the GLK for service after someone bumped my car, the guy said that my pads were still very much new so if this is not the way to do it, I'd rather not put wear on my tires and pads.

Any insight will be much appreciated.

Thanks in advance.

I have a 2010 4 Matic and had horrible brake squeal. I needed few front brakes and they ended up replacing all 4. While I didn't like the price, it was worth it as I no longer have any brake squeal. I can come to a gentle stop with confidence knowing my car won't sound like a truck!

I'm guessing the material changed in the pads. So one option, although not the cheapest, would be to replace all the pads.

I gotta agree with n8nu on the brake squeals. The GLK has horrible brakes and the only way to stop squealing is to replace the brake pads. Mine is squealing like jingle bells and I've only replaced the two years ago. The life on the OEM pads are very short and not the cheapest so I might look at other pads.

Thanks guys. That sucks as the guy that looked at my current pads said they still have a lot of life in them. Guess I gotta look at non-OEM pads.

Try giving them a good wash and try to get as much brake dust off the rims/pads/rotors as you can. That might help reduce the squealing.

I've read that a really hard stop will remove glaze and stop the noise.

My 2011 squealed almost from day one and it drove my wife crazy (crazier?).

I recently did a full brake job and absolutely no noise now. I made sure to carefully grease all the metal contact points so I am not sure if that or the new pads made the difference, but I'll take it regardless... :cheers:

I have a '10 glk 350, I tried EVERYTHING to get rid of the noise. I noticed the rotors were actually wearing out as there was a lip overhanging the pads. And those were the original pads at about 50k (kms). I think the squeal was a combination of softer metal rotors and the pad material. They worked well, but the noise and dust was ridiculous. I replaced the front rotors with an after market performance rotor (Ate brand) pronounced "ahtay"
and used wagner thermoquiet pads. I've had that combo now for 20k. No issues. Quiet as a mouse. Great initial bite and very smooth and linear predictable braking. I left the rear wheels stock. The wagner pads even have the proper hole drilled in them for your pad replacement sensor. Basically I haven't heard one good thing about the stock rotors. I wouldn't waste cash on pads alone. Just do both and then enjoy.....

Thanks for the additional tips. I'm going in for a scheduled service soon and see what they have to say but I suspect that they'll try to gouge me if they fix it so I'll see if I can get the replacements done elsewhere.

Also, possibly a dumb question but I've been looking on ebay for replacement rotors and pads. I think I may have to order online and then have someone do it for me because I'm pretty sure that these things are more expensive in Korea.

Anyways, dumb question: the rotors/pads are for a GLK350. They only sell the 220CDI in Korea. Should fit okay right?

Also, do you recommend just changing the front or the rear as well?

Thanks again.

In the U.S. most mechanics will not use parts supplied by the customer. They claim it is for warranty reasons but they also mark parts up and don't want to lose that $.

As to parts compatiblity, you probably should check with the parts seller.

Change the rear if they need them; if it ain't broke don't fix it... :cheers:

Squealing is not usually directly caused by the pads or the rotors especially if the are OE.

The squealing is caused by vibration of the pad metal backing against the caliper pistons. You can make the noise go away, by removing the pads and applying an anti-squeal paste between the metal pad backing and the caliper pistons. Just takes a light smear. Has to let sit for a while to cure. It is some sort of high temperature silicone. Available at most auto stores.