just checked my " $1/foot " vacumm hose on my 300SD. After one week of usage the hose is not leaking, ( a miracle considering the way I push that engine ) but it definatly has become softer and more malible. Looks like the heat is getting to it. I'll go to my supplier tomorrow and get OEM parts. The vacumm hose is a "fix on the spot" solution but isn't long term.