I just went through this on my 1998 E300DT.
I am curious about your car and what they offered in Ireland.
Do you have a sedan or a wagon? In the States they never offered the W210 wagon with a Diesel engine. We could only get the Diesel in a sedan.
The Diesel sedans were offered like this:
1996 and 1997 were NA OM606.960 engine, called E300D.
1998 and 1999 were turbo OM606.962 engine, called E300DT.
For the remainder of the W210 cycle they dropped the Diesel entirely in the States and you could only get a W210 gas powered, until the W211 came along with the CDI. Even then no wagon, only sedans, but you could also get an M-class with the CDI engine.
But I digress. Here are my hints.
- just go ahead and order the complete hose assemblies from M-B. I bought the complete set of 6 for around $100 US. If the hose is brown and brittle chances are it could be admitting air into the system.
- Don't forget the crush washers (items 126 and 128) for the IP return line. I did and now I get to pull the IM again to replace them when they come in.
Whunter has a thread on the hoses and part numbers:
1998-99 E300 Turbo Diesel Plastic injection pump lines, OM606.962
And here is my post from where I did this job, you may want to consider ordering a new valve cover gasket and the 6 o-rings, while you have it that far apart it is easy to change them.
Attn OM606 - inspect under the engine cover
And renew the injection line clips, pads, and spacers as well.
All told the parts bill was about $250 US and about 4 hours of labor on a Sunday afternoon. Money well spent on preventative maintenance.