Mercedes brake nightmare

[Falcon_LS]

About 2 weeks ago, I did a brake job on my '05 ML500. I had the rotors turned, and installed a set of German Trucktec semi metallic pads instead of the OE Mercedes ones (brake dust was a major problem).

All was well, and I was delighted not to have to clean the wheels ever so often, until the brakes really started to squeal under light and heavy braking. Took it to a few shops, thinking maybe I did something wrong, and they all told me I need to turn my rotors again. I only turn my rotors once before I replace them, and I refused to have them turned.

Later on, I took the truck out of town and did a series of hard braking from 100 MPH to the point where the brakes nearly faded. The squealing went away completely and the brakes actually grabbed better.

Two days later (today), the squealing came back.

Didn't use any paste on the brakes (always do), so I'm wondering if that had anything to do with it. Should I just bite the bullet and replace the rotors with a new set of pads?

 

[bmwtechguy]

Try the anti squeal "paste" first. Sounds like the brakes you got are a harder compound and those will squeal more readily than OEM.

 

[bluestream]

Most high quality pads have anti-squeal shims on the back. The cheap pads need the silcone bedding compound applied before they are installed. Let it dry 15 mins before install.

All pads can squeal a bit, I consider it normal

 

[Dieseldoctor]

does not say how many miles u have on it... but your suppose to put 1000 miles on them under light braking no sudden stops then after the 1000 miles of light braking your suppose to stop from 60-0 hard as possible to seat the pads 10 times. It's normal for them to squeal really bad for first 1K miles alot pads have brakein stuff on top to deglaze the rotors. I'd imagine if your rotors were done right first time and u shouldnt need anything done. Agian brake fade and squealing is normal for first 1K miles per ebc.

 

[JHZR2]

I bet the calipers weren't cleaned and lined right, so the geometry isn't quite right. It probably doesn't align just right with light use.

 

[Kestas]

The brake paste MB sells that goes between the pad and caliper is nothing more than copper neverseize compound.

 

[JHZR2]

But if the pins are grimy and not cleaned right, they won't necessarily slide right... Wentcthrough that on my truck when I went off-road a lot...

 

[mechtech2]

By all means, get some brake anti squeal sauce on the back of the pads.
Don't let it dry before assembly. Put it on and seat the brakes before it dries so there is no 'cushion' to make things spongy.
This should fix it in almost all cases.

 

[Vizzy]

Unless a car or vehicle is going to be raced or under extremely heavy duty use especially german makes you should ALWAYS use the OEM pads and rotors! I would bet your issue is due to aftermarket parts in this case, nothing else.

 

[rshunter]

Originally Posted By: Vizzy
Unless a car or vehicle is going to be raced or under extremely heavy duty use especially german makes you should ALWAYS use the OEM pads and rotors! I would bet your issue is due to aftermarket parts in this case, nothing else.

I've never used OEM pads and discs on my German vehicles, or any of the others for that matter. I've also never had an issue related to the aftermarket pads, shoes, discs or drums that I've used.

 

[bdcardinal]

Originally Posted By: JHZR2
But if the pins are grimy and not cleaned right, they won't necessarily slide right... Wentcthrough that on my truck when I went off-road a lot...


im thinking ML500 has fixed mulitpiston calipers so no sliders, although i could be wrong.

 

[Vizzy]

Originally Posted By: rshunter
Originally Posted By: Vizzy
Unless a car or vehicle is going to be raced or under extremely heavy duty use especially german makes you should ALWAYS use the OEM pads and rotors! I would bet your issue is due to aftermarket parts in this case, nothing else.

I've never used OEM pads and discs on my German vehicles, or any of the others for that matter. I've also never had an issue related to the aftermarket pads, shoes, discs or drums that I've used.


Perhaps you have been lucky.

 

[Scott_Tucker]

You need to have some sort of lubricant between the caliper and pads, and the piston(s) and pad. I use copper anti-sieze with much success. If you apply it now the noise may go away but it seems like you can sometime miss the window of when it will work.

 

[SteveSRT8]

you have simply been lucky.

Picking brake pads is very tricky.

There are millions of flavors.

 

[Falcon_LS]

Originally Posted By: bmwtechguy
Try the anti squeal "paste" first. Sounds like the brakes you got are a harder compound and those will squeal more readily than OEM.


The only place I can get the paste is the Mercedes dealer, and they close early before I'm able to leave work. Will try and ask for a favour from somebody, to see if they can get it for me.

Originally Posted By: Bluestream
Most high quality pads have anti-squeal shims on the back. The cheap pads need the silcone bedding compound applied before they are installed. Let it dry 15 mins before install.

All pads can squeal a bit, I consider it normal


Thanks!

Originally Posted By: Dieseldoctor
does not say how many miles u have on it... but your suppose to put 1000 miles on them under light braking no sudden stops then after the 1000 miles of light braking your suppose to stop from 60-0 hard as possible to seat the pads 10 times. It's normal for them to squeal really bad for first 1K miles alot pads have brakein stuff on top to deglaze the rotors. I'd imagine if your rotors were done right first time and u shouldnt need anything done. Agian brake fade and squealing is normal for first 1K miles per ebc.


Thanks for the info! They have about 1,300 kilometres on them, which works out to about 813 miles. I've attached a video of how bad the squealing is, and this is when the vehicle is driven slow. It's a lot louder when it's being driven faster. Not the best quality, but I hope it helps explain:

Video

Originally Posted By: JHZR2
I bet the calipers weren't cleaned and lined right, so the geometry isn't quite right. It probably doesn't align just right with light use.


Maybe that's where I went wrong, although I have followed the instructions in the service manual to the dot. I also removed the discs last night and cleaned them all with brake cleaner. Also rubbed the pads a bit on a smooth surface, sprayed them with cleaner and put them back on. There was no noise after that, but I think it's starting to come back again.

Originally Posted By: mechtech2
By all means, get some brake anti squeal sauce on the back of the pads.
Don't let it dry before assembly. Put it on and seat the brakes before it dries so there is no 'cushion' to make things spongy.
This should fix it in almost all cases.


Will do, thanks very much!

Originally Posted By: Vizzy
Unless a car or vehicle is going to be raced or under extremely heavy duty use especially german makes you should ALWAYS use the OEM pads and rotors! I would bet your issue is due to aftermarket parts in this case, nothing else.


To be honest, I've had it with the OE Mercedes pads and got absolutely sick and tired of cleaning up my wheels every other day. I know a lot of people who run German aftermarket brake products in Mercedes, BMWs and VWs yet they never seem to have any issues.

Originally Posted By: bdcardinal
im thinking ML500 has fixed mulitpiston calipers so no sliders, although i could be wrong.


Multi piston calipers.

 

[The Critic]

My friend's VW GTI had TRW rear brake pads from the factory.

When the replacements wore out, I told him to buy some TRW pads from worldpac.

The replacement TRW pads squeal like a bus, but the OE factory pads never did. Both are just as dusty.

Perhaps you should try a different pad.

 

[Scott_Tucker]

You should be able to get the copper anti-seize paste at any auto parts store or hardware store. I think it works best and I've done hundreds of brake jobs.

 

[The Critic]

Originally Posted By: Scott_Tucker
You should be able to get the copper anti-seize paste at any auto parts store or hardware store. I think it works best and I've done hundreds of brake jobs.

From my experience only, regardless of what the OEM or the pad maker says, any chemical (be it anti-seize, caliper grease or disc brake quiet) has had no effect on brake noise.

 

[Scott_Tucker]

Originally Posted By: The Critic
Originally Posted By: Scott_Tucker
You should be able to get the copper anti-seize paste at any auto parts store or hardware store. I think it works best and I've done hundreds of brake jobs.

From my experience only, regardless of what the OEM or the pad maker says, any chemical (be it anti-seize, caliper grease or disc brake quiet) has had no effect on brake noise.


In my 20+ years of professional experience, it makes a huge difference. Most of the noise you hear is the pads vibrating. It there is no lubricant between the pad and the caliper the caliper bracket vibrates, which causes the noise. Putting new pads and unmachined rotors can also cause noise.

 

[mechtech2]

Always use factory brake parts on German vehicles?
Nonsense.
Sure, there is a certain level of quality there, but you can met or exceed that, for sure.
And save big $.