It is a VERY common place for leaks on these cars. The lines do discolor and the O rings do leak, I don't believe the lines cracking is your problem. The most common leak source is the O ring on any of the clear lines. Some of the lines can be replaced with the IM in place. Replace the ones you can and see if that solves your problem. If not the IM isn't that hard to R+R. Don't forget; there is an O ring behind the shut-off valve and another on the pre-filter. The one on the pre-filter isn't a standard size O ring so don't try to "make one fit". Buy the right one from MB. That $2 O ring cost me $700 at my FORMER indy's.

Sounds like you have a relatively common problem for these cars. If you can, just replace all the clear lines and O rings at the same time. That should solve your problem.

__________________

Muleears
'07 E320 Bluetec 133K my DD
'04 Jaguar XJ8 VDP, 34K
'10 Hyundai Accent 60K Grocery Getter
'02 VW Golf soon to be on the road again
'97 E300 Diesel Son's DD
'61 VERY tolerant wife

Hampton Roads, VA USA

Gone but not forgotten:
'67 250S 95K
'86 300SDL
'87 300D Turbo, 364K! R.I.P.
'98 E300 Turbodiesel, 213K
'02 S420, 164K
'01 Prius 138K