As d.delano says, stick genuine MB on this item if nothing else.
I also got stuck with no-start condition due to a crack in the hose that I REPLACED. CRP brand. It cracked on the underside out of sight. Luckily I found it 2 days later after scratching my head. It was less than 1 year old.
Follow this as for the trick to get the one that snakes under the intake manifold:
http://w124-zone.com/articles.php?article_id=35