I don't think so, my 190E 2.6 was easy...should be straight forward to change the fluid. Are you using the one-man pressure bleeder? They do work awesome. And that Castrol is better than average fluid; also ATE Super Blue is nice stuff...I put that in my 500E and it made the brake feel noticeable firmer. Micheal turned me on to the Castrol and I put it into our Volvo 850 GLT. Also nicer than stock stuff.
Of course, MB wants you to use their OEM stuff, which is also good for most all driving conditions....can't be wrong if you did use it. Don't get any on the paint or your hands though...nasty little viscous chemical compound.
You probably knew that already...
