I have door lock problem with my 1985 300D.

It started yesterday, I could not shut off the engine.

After searching on this discussion board for related information about the door lock and vacuum diagnosis, I have isolated the problems to a certain extent. But not quite to find out the exact culprit. Thats why I am asking for your help.

I can shut down the engine with the following combinations connected:
Driver Door /Left R Door
Driver Door/Right F Door
Driver Door/Right R Door
Driver Door/Fuel cap and Trunk

Any 3 doors combinations connnected will not shut down the eninge.

Each time with the abvove combinations connected, I waited 3 minutes to lock the car. It will lock ok (of course only the driver door plus one door). However, after 30 minutes I try to unlock the door, the driver door will unlock, but not the other door (or trunck if it is in the combination).

So is that safe to say there is a leak in the driver door, or in the engine compartment or the vacuum reservoir?

Is there a vacuum element in the driver door? How do I check vacuum leak in the reservoir? Where is the resevior?

Anybody has any suggestions what else may be wrong and where else I should look?

Thank you

Steve

Here is a troubleshooting article which applies to the 123/126 chassis cars. http://www.mbz.org/info/articles/interiors/vacuum/

Steve

Get yourself a Mity Vac . I am new at major car repair and didn't have a problem finding info on trouble shooting vacuum leaks. Its fun and you'll save lotsa $. I do not know enough about the system to give answers to your particular problem but there are lots of folks around here that may. Like I said, get a mity Vac and start in the engine compartment and work back. Pull the floor mats up and look under the plastic covers on the outboard sides of the foot wells, there are lots of vacuum junctions there. I just went through this drill last week, it really is not that bad. Good Luck

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

The suggestion to get a mighty vac is a great one. I was a bit confused until I got one. $29.

I believe that you might have a leak in one of the yellow/green lines (open).

It sounds to me like you're checking each door but doing with both red and green hooked up. Culprit is most likely in either red or green and there is no way to tell unless you plug one and test the other.

So start with the:

Driver's door alone (plug all other vacuum leads with golf tees)

Next: Add driver's side rear
Next: Add passenger's side front
Next: pass rear door
Next: fuel/trunk

Everytime you do one, check both green and red with car on and off. If one is somewhat leaky, keep it plugged and go on to the next door.

What I generally do is keep one function of one door plugged until I purchase a new actuator. I drove for one year with the back passenger door unable to unlock (had to do it manually). That is because the actuator's green line function was leaky.

Hope this makes sense

Don

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DAILY DRIVERS:
'84 300DT 298k (Aubrey's)
'99.5 Jetta TDI IV 251k (Julie's)
'97 Jetta TDI 127k (Amber's)
'97 Jetta TDI 186k (Matt's)
'96 Passat TDI 237k (Don's
'84 300D 211k Mint (Arne- Undergoing Greasecar Conversion)

SOLD:
'82 240D 229k (Matt's - Converted-300DT w/ 4 speed

Thank you all for your replies.
I will get the MityVac and work on this weekend.


Thank you


Steve

Hi
I got the MightyVac and worked on the door lock problems this morning.

I finally found out the Driver door's master vacuum switch is leaking. The passenger door's vacuum element has a small leak on the unlock line. I ordered these 2 parts from FastLane and will replace them next week.

The MightVac is a very helpful tool indeed. Mine has brake bleeding kit with it. So next time I will use it for brake fluid bleeding.

Thank you again



Steve