no not on a 1998 C230, I have one. ( at least not the ABS unit that my model uses - guess there could be a possibility that they used different ABS units as they used different power steering units on some model C-class).
BTW Startuned magazine available on the web has an article on the ABS unit bleeding (on mercedes cars that apply).

I just did a brake fluid flush on my car and the pedal has good feel not mushy, I'd had a mushy brake due to when I did a sloppy brake flush.
I pressure bleed and was very careful not to let my reservoir go empty and wait for all bubbles to dissipate from each caliper.