Brake pads partly rubbing on disk (sounds like a steam train)

[Paragon1970]

Hi Folks,

I hope someone can help.
My S211 E280 2008 Estate has this weird issue on the offside brake caliper and disc.

When rotating the wheel it partly rubs in a certain place which makes a shhsh shhsh shhsh noise while driving, particularly prominent when creeping along in traffic.
Can also be witnessed when jacking up and rotating the wheel.

Things done, removed wheel, rotated disk by hand and notice a side to side movement of the disc which corresponds to the rubbing at the inside pad closest to the cylinder.
Suspected the discs were warped so forked out for a set of new ATE discs and Telstar pads.
After fitting the new components I still noticed that the disc is not running completely true, there is a slight side to side movement but it does not seem as pronounced as the old disc.
Problem is I am still noticing the noise after replacement.

Anyone have any idea what the problem could be?

Kind Regards.

 

[AMGeed]

Did you thoroughly clean the hub with a wire brush before fitting the new discs?
I suspect that is the problem if the disc is moving "side to side"

I would remove the caliper and disc, wire brush the life out of the mating face on the hub, refit and try again.

 

[Paragon1970]

Thanks for your reply,
I did clean the hub face with lite abrasive particularly around were rust spots were showing.

One thing to note I also gave the hub a lite smear of copper grease. (not sure if this was a good idea)

Incidentally the hub and knuckle was replaced sometime years ago due to a wheel bearing exploding without warning while on trip through france, probably not related, I never really noticed this noise until recently, but then that's not to say it wasn't there as I've also had major issue with the rear parking brake drum system causing heat and rubbing issues, to the point I removed the things, so they may have been masking the noise, i dunno, cars been a bit of nightmare, but in fairness only when it comes back from work done at the indies i've used.

I think I need to get a dial gauge on both the disk and hub and check the run out, though I'm not sure what is acceptable.

 

[slade1]

Had similar problem with CLK. The disc on inside had what looked like blow holes, like aftermath cutting torch holes !!
New discs fixed the problem.

 

[optimusprime]

I chamfer the material off the leading edge of the brake pad with a file .Not a lot just rub the file over it a few times .Some pads are liker this from new so you dont have to do anything to them

 

[Neiltodd]

Have the same issue, have also replaced discs and pads and still there. My description is exactly as you have said, sounds like a steam train.

 

[Paragon1970]

Thanks for your replies. Sorry to hear you also have this similar problem Neiltod.

So circling back with an update.
Turned some spacers so as to tighten the brake disc to hub with the wheel nuts, without the wheel attached, this is required so as to get an even mount across the face.
Without installing the above runout is around 0.3mm due to the small torx star bolt which retains the the disc to the hub.
Checked run-out of new brake discs seeing around .03 mm which is about right from my understanding.
Experiencing no noise when hand turning with wheel on or off.

I also checked the nearside wheel by jacking it up and rotating with wheel on and my initial check seemed ok, I could hear a consistent sound from the still original brake pads, so thought no more about it.

Took car for a spin same annoying sound no change.

Rotated tyres, just incase .... no change.

Though this time I had the feeling noise was coming from the yet to be changed (brakes) nearside wheel, the one that initially seemed ok.

Jacked car up and spun the nearside wheel... whoosh whoosh whoosh. What the heck!!?

Started to replace nearside disc and pads but before attaching new and with everything removed, spun the hub again there was the same sound and friction with the heat shield.
Removed three heat shield torx screws but the thing was jammed solid and the friction continued.
Checked between the heat shield and hub and noticed material that was quite hard (looks like foam, bit like the strips one uses for door draft excluders) pried some of it out to clean it up which allowed for a little movement of the heatshield, fastened it down noise gone, hub spins freely.

Commenced with fitting of new pads and disc ensuring everything was clean.
Put wheel back on and tightened to spec (130nm)

Span wheel whoosh whoosh whoosh... What the!!?
Figured / hoped the new pads just needed bedding in.... but alas no, issue persists.

Now something to point out..... Thanks to an over enthusiastic idiot tyre fitter the wheel nuts were way over torque, so this may have been the catalyst of the issue, but cannot be sure.

Trying to figure out if the hardened foam type thingy between the heatshield is a required thing or whether it was something picked up. I dunno.
Wondering if the problem could now be due to a deteriorating reluctance ring (thinking aloud while clutching at straws)

So problem still persists.

Hope this rather long post may be helpful for others.

Oh forgot to mention, while screwing on the brake fluid cap, it slipped out my hand and fell into a never never region of the car, spent half hour fishing the darn thing out. Oh boy, oh boy... LOL

Cheers.

 

[Paragon1970]

Thanks for your replies. Sorry to hear you also have this similar problem Neiltod.

So circling back with an update.
Turned some spacers so as to tighten the brake disc to hub with the wheel nuts, without the wheel attached, this is required so as to get an even mount across the face.
Without installing the above runout is around 0.3mm due to the small torx star bolt which retains the the disc to the hub.
Checked run-out of new brake discs seeing around .03 mm which is about right from my understanding.
Experiencing no noise when hand turning with wheel on or off.

I also checked the nearside wheel by jacking it up and rotating with wheel on and my initial check seemed ok, I could hear a consistent sound from the still original brake pads, so thought no more about it.

Took car for a spin same annoying sound no change.

Rotated tyres, just incase .... no change.

Though this time I had the feeling noise was coming from the yet to be changed (brakes) nearside wheel, the one that initially seemed ok.

Jacked car up and spun the nearside wheel... whoosh whoosh whoosh. What the heck!!?

Started to replace nearside disc and pads but before attaching new and with everything removed, spun the hub again there was the same sound and friction with the heat shield.
Removed three heat shield torx screws but the thing was jammed solid and the friction continued.
Checked between the heat shield and hub and noticed material that was quite hard (looks like foam, bit like the strips one uses for door draft excluders) pried some of it out to clean it up which allowed for a little movement of the heatshield, fastened it down noise gone, hub spins freely.

Commenced with fitting of new pads and disc ensuring everything was clean.
Put wheel back on and tightened to spec (130nm)

Span wheel whoosh whoosh whoosh... What the!!?
Figured / hoped the new pads just needed bedding in.... but alas no, issue persists.

Now something to point out..... Thanks to an over enthusiastic idiot tyre fitter the wheel nuts were way over torque, so this may have been the catalyst of the issue, but cannot be sure.

Trying to figure out if the hardened foam type thingy between the heatshield is a required thing or whether it was something picked up. I dunno.
Wondering if the problem could now be due to a deteriorating reluctance ring (thinking aloud while clutching at straws)

So problem still persists.

Hope this rather long post may be helpful for others.

Oh forgot to mention, while screwing on the brake fluid cap, it slipped out my hand and fell into a never never region of the car, spent half hour fishing the darn thing out. Oh boy, oh boy... LOL

Cheers

 

[Paragon1970]

Ok so I think I know what the spongy foam thing is / was.... it what the ABS / speed sensor sits in.

Actually ignore the the above. I saw the sponge thing on a video of a s-class w220, I don't think it applies to the W211 setup.

 

[Neiltodd]

Mine now fixed, turned out be a loose parking brake cable rubbing on the drive shaft.

 

[Trickythemerc]

Did you replace the clip or do the cable tie bodge ?

 

[optimusprime]

Neil well who would have thought it would be that ...you did say brakes ,,it took me of the scent Thjs is good news my frioend ..

 

[Neiltodd]

Did you replace the clip or do the cable tie bodge ?

It was repaired by mercedes dealer so I'm not sure what they did, hopefully the clips.

 

[Paragon1970]

Glad you sorted your issue.
I still have the problem but in my case it can't be the parking brake since the problem is on the front wheel.
Received new hub assembly with pre fitted bearings yesterday, so aiming to fit today.
The only thing left to replace is the bearings, brake disk and pads have been replaced, dust shields have been checked.
Fingers x'd this will resolve the issue.

 

[Neiltodd]

Glad you sorted your issue.
I still have the problem but in my case it can't be the parking brake since the problem is on the front wheel.
Received new hub assembly with pre fitted bearings yesterday, so aiming to fit today.
The only thing left to replace is the bearings, brake disk and pads have been replaced, dust shields have been checked.
Fingers x'd this will resolve the issue.

Myself and my local mechanic initially thought front Left Wheel and changed discs pads etc with no change to the noise but MB picked up the real cause (Parking brake cable not the actual brake)

 

[Neiltodd]

Ps hopefully you get it sorted, it was doing my head in.

 

[Paragon1970]

Fitted new hub front wheel drivers side.... no change. :-(

On a bright note pretty much everything wheel and brake related up front is brand new now;-)

I'm actually left with tyres though I did rotate them, but they are the same make, they are also winter tyres as never bothered changing back to summer, due to lack of use (covid).

Unless I am experiencing the same issue you had with parking brake cable.

Neil, so to be clear are you saying you thought the noise was from front but it turned out to be coming from rear since this is where the parking brake cable runs, it then splits in a Y shape to each of the rear wheel hub drum parking brake shoes. So in your case the cable came loose and was rubbing on the drive shaft to rear wheels?

Was your noise more prominent when turning?
In my case turning left seems to make it more prominent.