The 3 mm id x 9 mm od vacuum hose 007 977 61 82 feels slick on the outside -- like many silicone vacuum hoses. The MBZ hoses is going on 30 years old and looks brand new for the door actuators. I've used non-MBZ vacuum hose only to have they crack within a month.

Is the MBZ hose silicone or silicone modified? Some on the vacuum hoses in the engine compartment show some cracking, but what do I expect after 30 years? I'm thinking of using silicone vacuum hose, but silicone tends to slip more than rubber. I don't want to take apart a door panel to reconnect a slipped hose.

BTW: silicone hoses have 3.2mm id x 2.0 mm wall but the OD is only 6.8 mm. It looks like some round 1.8 mm wall to 2 mm.