vacuum hoses - where is the other end?
 

I have a vacuum leak on my '78 123. It has been leaking since last winter but I have been living with it. If I lock the drivers door it slows it down enough so that everything works but the passenger door lock and sometimes the trunk lock. My question(s) is:
can I just disconnect and block off the door lock system for now?
If I can, where are the other ends (not in the door) of the hoses?
If I can't, I still need to know where the hoses go. Are they long hoses that go all the way to the engine compartment ? I lost track of them when they passed out of the door.

As per usual, thanks for all of your excellent help. -Andy

on a totally unrelated note, has anyone here ever taken apart a Saab manual transmisssion? My selector rod is stuck. the car only has second gear. -Andy

Andy:

You can disconnect the yellow plastic line in the engine compartment and plug the engine side. This will seal the vac system while disabling the door locks. If the tranny shifts better afterwards, you have a leak.

I suspect from your description that you have either a bad rubber connector at the door switch or a bad door switch. Usually a bad diaphram (see below) prevents anything from working.

The locks work by a switch in the driver's door, supplied vac via the yellow line. The switch sends vac down the yellow with a red stripe (I think) line to the other doors, trunk, and filler cap locks. Unlocking the door switches vac to the yellow with green line, and vents the yellow with red, this applies vac to the other side of the lock diaphrams and unlocks them.

Get a MitiVac if you don't have one, and see if you can pump the lock system down. If so, you have either a leak in the vac supply or in the reservior (under the left front fender). A dead check valve (little round plastic thing) in the yellow line by the brake booster will also cause slow or dead locks as the vac bleeds off with the engine off.

You will need the mitivac to check the locks, anyway. You may have a broken line or bad diaphram, causing the others not to work.

Peter

Exactly what I needed to know. I pulled the door panel off my parts car and saw the lines and switch mechanism, but I did not know which did what and where they went. I will get a mity vac and start pumping. Thanks a bunch. -Andy

I wouldn't disconnect the locking system. The more stuff that doesn't work, the more your car turns into a piece of crap. It's probably just the trunk lock vacuum cylinder and/or maybe the one on the passenger door. I wouldn't even waste my money on a Mity-vac for this one, I bet it's one of the two. If the cylinder is good, you will not be able to move it back and forth with your finger over either of the air holes. I f you can...it's bad. It cost nothing to check them this way.

with a four year old, a two year old, and a nine month old, it is already the family truckster. I am just trying to tread water with it right now. thanks for the tip about the cylinders, they should be cake to replace. -andy