It's been a couple of weeks now since I replaced my cooling lines. I thought I'd provide an update that may help someone in the future if they come across the same issue (which is probably less and less likely as I don't see many W211's still on the road).
It turned into a pretty big job. There was no way I could see to replace the lines without removing the bumper as there was no access to the connection into the radiator, without even factoring in 20 years of rust/corrosion welding the two parts together.
In the end I bit the bullet and removed anything near the lines; bumper, fan, intercooler, air ducts, trim pieces/panels etc.
With the 'spring clips' removed from the connections at the radiator there was no way of seperating the actual oil line from the plastic radiator connection without causing irreversible damage. I ended up hacksawing the pipe off so I could turn the entire radiator connection with a spanner, before using a masonry bit as a punch, along with a hammer to seperate the remaining piece of cooling line from the radiator connection. I then cleaned the connection up with sandpaper and a dremel in order to provide any chance of pushing the new oil line connection into it.
I used a bit of silicone around the radiator connections I was reusing (when I reinstalled them) as I didn't think it was going to create a seal otherwise.
I connected the new pipes and replaced everything to its correct position, topped up the transmission fluid and coolant (with the intention of doing a flush soon anyway) and I've done around 500 miles since, with no loss of fluids (I've left the undertrays off underneath and checked periodically for any signs).
Below I'll post a couple of videos that helped me along with an itemised list ot part numbers/cost.
- this video proved invaluable right when I was in the middle of the job unable to remove the old pipes. Saved me buying a new radiator.
- this video made me completely overthink the process of connecting the new cooling lines. He goes on and on for almost 20 minutes explaining how to fit the new connectors. It really isn't that difficult, just line them up correctly with your new pipes (once they are fully seated) and snap the spring clips down. That's it.
Parts were ordered from Mercedes Newcastle who are pretty spot on and I was pleasantly surprised at the prices.
A 211 270 05 27 - Oil Line (Top) £42.36
A 211 270 00 27 - Oil Line (Bottom) £42
A 000 277 05 54 - (Plastic Sleeve) £3.48
5 Litre Transmission Fluid - £27.88
PARTS I DIDN'T USE
A 028 997 62 48 - O Ring £2.58
A 000 277 05 54/B (Spring Clip) £5.34
I didn't use the above parts as they came as part of the items I'd ordered above them (seals = oil line, spring clips = plastic sleeve) something which Mercedes Newcastle couldn't confirm at the time of ordering.
Anyone still reading this far is probably gearing up to do this job. It'll take a few hours and you'll fight with those old connections but it's straight forward enough.
Good luck
