Need honest opinion here.

I went to my indy shop for a caliper rebuild after hearing knocking sounds going over bumps.

The tech says I may need to buy an entire new caliper as it may be damaged resulting in the sound.

You can clearly hear the noise when jiggling the caliper left and right here is a video:

https://youtube.com/shorts/WKZfNATEanM?si=WF9HFk1A0nQ86h1O

This video is after the shop has "rebuilt" it.

Your thoughts?

 

you sure it's not a loose caliper bracket bolt or something? I've never seen a caliper move like that

 

i doubt it, the tech disassembled the whole thing, greased it up and tightened it back in place...

 

"May need" a new caliper? If the caliper is flopping around, something worn should be apparent. I'd take it to the dealer ASAP.

 

It is not clear from the video whether the caliper (the assembly that slides and has the brake pads attached) or the caliper support is moving and the source of the noise. Your finger tapped the caliper support, but since the camera was jiggling with your jiggling of the caliper... it's not clear if the caliper is moving in relation to the support. It seems a caliper thing.

If the sliding caliper assembly is what's moving, then you have a pin, boot, or anti-rattle clip that isn't right. We'll assume brake fluid is clean and topped off. Did you use 100% OEM parts? Were all conceivable wear parts replaced in the rebuild (since all the itty bits appear to be orderable separately... I looked up 2018 E63s since that's what's in your profile... https://mbparts.mbusa.com/v-2018-mer...s-and-fittings) Brakes are tricky. There's a lot of nuance and tradeoffs in the tolerances of the parts.

Also, the rattle sounded like it could be splash-shield related. Splash shield can get hit by road debris and bent, or a bolt could be loose. More of the characteristic splash-shield ting-ting sound than the thud-thud of a heavy caliper knocking against fixed support.

 

Thanks for your input, I brought it in today and analyzed the whole thing.

All parts are OEM from MB, there is quite a bit of play in the caliper but the sliding pins show no wear or damage.

the pads were removed and glued back in the caliper using urethane and so far no more noise 🤞

 

Curious.
Glued?

 

yes, they applied urethane to the back of the pads before sliding them back in the caliper.

Zero noise.

 

I’d say you need a new shop

 

at no time in any car that i seen to include million dollar rides has "glueing" pads ever been a thing or a consideration!

with that said, glueing pads won't fix the issue you showed with the caliper clunking and clapping as it moved everywhere.

 

Special formulations of polyurethane glue are good up to 150Deg C. Your calipers can easily run as high as 200Deg C. 150Deg C glue + 200Deg C temps = disaster.

 

Slap some duct tape on it

 

@AhMyGod
The urethane thing is a red flag. I've never seen that in any vehicle maintenance procedure. Now I think there's an issue with how the brakes are applied and then back off the rotor. Again, tricky. Don't want drag, but don't want too much space or pedal feel will suffer. I now wonder if you're seeing sub-par brake performance. Brake squeal is a pain, but generally doesn't occur if everything is clean. I've seen this lubricant (not glue) used to prevent squeal and facilitate caliper movement (braking and release).

I suggest the brakes be disassembled and cleaned of all foreign material. If any urethane migrates to the cylinder walls, the pistons will stick.

 

Some brake pad shims comes with rubberized coating. Are they trying to replicate that?

Otherwise I grease all the brake parts with this

 

While inspecting the 3 other brakes (which the discs and pads have been replaced by my MB dealer) they are all "glued" with polyurethane to the calipers.

It's just that one side that somehow is making noise while driving on unequal pavement.

I am taking a wild guess here and it could be another chemical than polyurethane but it sure as hell looks like it.

 

Polyurethane makes foam products and wood floors shiny. Are you just talking about brake grease?

 

First thing is to remove the cap and see what's happening underneath. The red plate that says AMG pops off, just pry it with a screwdriver, then you can see what's happening underneath.