1981 240d WIERD
 

Ok i installed a subwoofer in the back of my 240d and i had to drill a 3 inch hole in carpet through the metal into the trunk for it to sound right. before i drilled i checked to see if anything was gonna be in the way and there was one thing... a plastic bubble thing... its about 2 feet long and 1 and a half feet wide and it goes right into a spot on the roof of the trunk. there was a tube connected to it and when i cut it air hissed and then stoped... when the car is on the tube connected to the plastic bubbles sucks in air. what the heck is this thing and do i need it? can i just cap off the tube and call it a day or is it actually important

That's the vacuum tank. It's function is to retain vacuum when the engine isn't running, this will allow the automatic door locks to work when it's not running.

sooo do i need it? and if so how do i put the line back together?

take
 

a piece of pipe a size that will fit inside the tube tightly and push it into the two ends of the vac line. done.

tom w

uhh.. will rubber shrink wrap work? like cut a peice 2 inch long stick 1 inch on one end and the other inch on the other end and take heat gun to it and shrink it on

Also anyone this is to anyone that has the 240d, do you find the vacuum lock a useful feature or could you do with out it. cause i think it looks very ugly and it uses up trunk space...

i am not sure if shrink
 

wrap will work or not.

personally on my old benzes the vac locks are mostly dead. they are nice when working but not worth the trouble to fix when dead...to me.

tom w

I don't know, you may have better luck putting a length of smaller hard plastic tube inside both ends of the cut tubing.

I personally like the connivence of the locking system (and it really annoys me when anything doesn't work correctly). My wife like to be able to lock all the doors when driving, etc. It's your car. BTW, if the tank is installed correctly it is way up against the top of the trunk where you shouldn't even see it.

hehehe it was installed correctly just i needed the subwoofer to sound right so i had to take it out. i guess ill put it back in just because. ty for the help.