I have been bothered by a serious defrost problem of my '89 240DL, until recently I discovered that the vacuum hose that comes out of the firewall behind the glove box of engine is not attached to anything. The end is deteriorated, broken into several pieces. There is a small metal "L" shape tube that comes out from a big black hose going to intake manifold. Is the hose supposed to connect to this tube? Could anyone suggest how I repair the broken hose? Or should I replace it?

From what I read in the past messages, I believe that the other end of the hose is connected to a vacuum actuator that controlls the three vent switches (floor/defrost/recycle). [Am I right?!] If so, this might solve my defrost problem.

I will truly appreciate if anyone can help me out!

thanks,
vincent
cambridge, ma

The hose you describe does attach to the metal elbow at the intake manifold. If the hose is damaged in several places, replacement is best. Get about 3 feet of hose the same size. Remove the plastic center console side panel on the pass side. The hose conects to a plastic vacuum reservior behind the panel. Disconect and pull the hose out of the gromet that goes through the firewall. If you have some silicone spray lube, spray the hose and it will come out easier. Now feed the new hose through the firewall gromet and attach both ends. Should take 5 or 10 minutes.