Please read the bolt/socket size chart in my signature line. Should be sticky. Should be required reading here.
There is no such thing as an 11mm German cap head screw. DIN 912 defines German cap head hex socket screws. It has now been withdrawn in favor of the identical ISO 4762 (both are shown on my chart).
Its possible you have a US spec 7/16" cap head screw. But that should give you pause. Why would a US spec bolt be on a German vehicle? (could Mercedes be buying brakes from the US? Unlikely. Mercedes INVENTED disk brakes in the early 20thc).
I believe the caliper guide bolts on a MB ML are T40. Sometimes, especially on brakes, the recess fills up with black brake lining and you can squeeze a hex bit into a torx head bolt.
But please be sure, as you will likely strip the torx recess with a hex bit. These caliper bolts may be torqued to nearly 100ftlbs from the factory and there may be some sort of locktite applied. You will not strip a torx recess with this torque, but you could shear a low quality bit. I can pretty much guarantee Lisle or Craftsman, maybe even Blue Point, will struggle or fail.
I know you don't want Snappies, but they are the recognized best bit sockets out there. Bit sockets are the reason I started using Snap On. Ditto, you may need more than 150ftlbs to loosen these babies. So you could be risking breaking some 3/8" ratchets. The Snap On dual 80 3/8" drive is one of the strongest ratchets on the market and I think it's good for 250ftlbs.
You might do okay with other brands or you might not. I recommend you buy bit sockets directly from Snap On so you have warranty service, then swap them out as they become worn. On the flip side if money is tight, you can buy sets pretty cheap on ebay and buy replaceable bits direct from Snap On for 10 or $12 each. The chrome doesn't really wear, only the business end of the bit.
Last- I don't have one of these vehicles to look at, and I'm not 100% sure I'm right about the head size. Check before you splurge!
