Is it a M103 engine?

Never did it myself,

I would try without removing any pump etc. I believe that the length is so short that one can squeeze that hose.

Just a hint if it can be of any help for you. if I would have to do it, I would use the lubricant used by shops that mount the tyres. I use it every time and it makes the rubber to slip so fine that it is amazing.

Keep us posted.

Good luck

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Keep us posted especially if your problem is solved
Present cars:
My car: E-class 420CDI, 2008, W211, V8, 180 000km

Wife's one: C-class 220CDI Sport Coupé, Euro, 2002, W203. 345 000km

Son's one: GLK class 220CDI, 2009, W204

Sold E class 260E, W124, 1988 beloved car sold after 489 000 kilometres of reliable services (engine M103, clutch and 5 speed manual gear box all original).

E-class, W210 320CDI, 2000[/B], 225 000km, Sold