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I have a 2010 A207 with the AMG brake pack. To make sure I got that right, my pad carriers are the A2044211194 version and look like this. The pads are the type with that little claw on the back, A0064202820, which look like this.
My car has a loud rattle whenever I go over a bump or something like a drain cover, which is really unpleasant with the roof off. I am confident that the source of it is the brake pads, as it is exactly the problem this guy describes and shows here,
, and it disappears with gentle brake application.
I have tried:
Using normal copper grease on the back of the pads.
Using copper grease on the pad carrier rails, which helped for a bit, but not long.
I have tried tightening up the claw, but it still doesn't have much force to it.
These pads came with the car when I bought it, I think they're main dealer parts but I can't be sure. They've loads of life left in them so I'm reluctant to replace them on spec.
What can I do? Should I be investigating some kind of adhesive between the pad backing and the caliper? Could it be that my pads are poor copy parts?
I would think the claw on the back of the pads should prevent this. Perhaps the pads overheated at some point and ruined the temper of those claws preventing them from gripping in the caliper piston as they should. I would also suspect the clip on the front of the pads as being "sprung" for want of a better term.
Pads are relatively inexpensive and not a hugely difficult job to replace. I think it might be worth doing if this is the cause of the rattle. Of course I detest rattles and they drive me bonkers till I find and fix the cause.
Thanks, John, I think you're probably right - and at £40 for a new pair, it's the best approach. Looking at these ones from Euro Car Parts they appear to have the spring plus some kind of adhesive padding too. That ought to do the trick.
I have this same problem as outlined in the video (there's another video floating on YouTube). The issue is the outer pad that has the adhesive backing to it, not the inner pad that has the shim on the backing plate that affixes to the piston.
On most floating caliper designs, there is a shim or anti rattle clip that goes on the top side of the caliper to hold both pads in. On the W212/207, this is not the case.
The adhesive tape is important!
About 2k miles ago I installed akebono Euro pads, as I've used their proACT pads and enjoy the low dust. First 900 miles or so, tolerances were tight, and everything seemed great. Rattling went away. However as the pads wore in, a rattle appeared on heavy bumps that went away anytime the brakes were applied.
After much back and forth with the engineering team at akebono, im getting a full refund. From my tear down, the front pad has a nipple that sits in a groove in the caliper. Other than that, nothing holds it in place. As the pad wears down expect even more noise. I have videos and pics to show this (I'm on vacation). I installed all new hardware at the time of install also to minimize any other potential issues.
I ordered OEM ferodo pads. I will be installing them asap. I will make sure to use prepsol (or any other oil, wax, adhesive remover) on the inside of the front facing portion of the floating part of the caliper to ensure the adhesive sticks.
the pad when the brakes are not applied, start to move around. This is hard to replicate on a lift. I used a rubber mallet on the hub/knuckle and barely got any noise. On a bump however you hear it. On my still new pads the noise happens only on bad bumps. As you can expect as the pad wears down the tolerance will increase and with nothing to hold the pad in place between the caliper and rotor, a noise will occur. This is where the adhesive is paramount.
im surprised this issue has not surfaced the internet sooner (or more).
Speaking to a star technician, he told me he encounters this issue almost daily. The adhesive is the "fix". Who knows how long it'll hold. I may even plan to add even more adhesive (brake pad adhesive).
Bad design on part of MB on their floating caliper design. funny enough the w213 has a fixed caliper.
Thanks 12E350, it looks like you've nailed it. It does seem like a really poor design, especially on a car that is more about luxury than performance I would have expected them to work hard to get rid of rattles!
Time for some new pads and some adhesive methinks...
Anyone try adhesive strips on the back of aftermarket pads for this issue? I suspect my aftermarket front pads are causing the knocking noise i've been hearing lately but I don't want to to go back to oem pads. I'm assuming it would need to be a high heat adhesive tape?
Would also be interested to know if anyone has an aftermarket or oem version of this pad that is ceramic that comes with that adhesive backing. Looks like the oem part number is 007 420 58 20
I've found if you don't have the adhesive backing, you can put a little(very little) high-heat RTV to hold the pads in place. sticks well and cleans off easily when replacing pads the next time
Hey all, so I tracked down an annoying rattle in my front brakes to the caliper bolts being loose in the knuckle. The caliper bolts are torqued to beyond spec and the caliper and rotor are still able to move freely from the knuckle.. So i guess either the two bolts have chaffed away or the knuckle opening has widened to allow the bolts to bang around. Does anyone know if the knuckle is threaded where the caliper attaches to it or is it just a smooth bore?
Trying to figure out if I need two new bolts or a new knuckle. Maybe if its a smooth bore on the knuckle I can get away with wrapping the bolt to shim it in there so there is no play?
Thanks!
Edit: to be clear I'm talking about the bolts that hold the caliper to the spindle/knuckle, not the slide bolts.
Last edited by Late; May 6, 2023 at 05:49 PM.
Reason: more information
if I'm seeing this correctly I believe the two circled points are where the caliper bolts thread through. They look to be smooth bore with no threads? So i guess the when the caliper bolts are torqued into the caliper it compresses the knuckle against the caliper?
Just to finish this off. took the two caliper bolts off and they are threaded all the way through but the knuckle is a smooth bore.
The threads wore down to nothing where they were contacting the knuckle which was causing the banging noise over bumps and while braking.
As a temporary fix I wrapped the end of the bolts where they make contact with the bore of the knuckle with steel wire and added a poly crush washer to squeeze in when torqued back into the caliper.
Worked like a charm but I have new bolts on order as no one carried them locally.
Seems like a dumb design to me... why would the bolt be threaded up to the head? Does anyone know of a company that makes one like this in our size?
Late: From what I can gather it sounds like you're saying the bolts were loose and pounded a thread impression in the knuckle? This is no biggie as a general rule, as long as the threaded holes in the caliper are good. I do wonder since you said they were torqued to spec but the assy was still loose? I'm confused...
It would be nice if the bolts had a shoulder that fit, but then it would upset the bolt stretch needed and cost more. As long as they're torqued good they should never move, so I'd assume the last guy that touched 'em didn't torque 'em?
Yea great point I was confused as well, I had a 3 ft breaker bar when I initially saw the loose bolts and tried to tighten them but both bolts would not tighten anymore. i was able to break them loose and tried retightening but the slop was still there. maybe the bolts were stretched from previous install or they were too long? i guess ill compare when the new ones come in.
My temporary fix seems to be working so far ( about 100 miles on it since this weekend) The sacrificial poly washer i added did squeeze in with the wire that i wrapped around the shoulder of the bolt and effetely sealed the bolt into the bore wholes on the knuckle. The head of the bolts clamped in the excess washer that bulged/squeezed out when tightened so maybe that little space being taken up by the rubber was the actual solution. ill be sure to take some pics when get the new ones installed
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Rattling front brake pads
