Vaccum lock question.. - PeachParts Mercedes-Benz Forum

crashone · #1 01-27-2007, 08:04 PM

Today I noticed that my trunk wouldn't open so I turned the key in the driver's side door to relock the system. Well there was nothing there. The key only unlocked the driver's side door, no automatic unlocking, no pump moter sounds, nothing. I checked the fuse (#13) and that seemed good. My spare fuses are in the trunk. Do any of you guys have suggestions as to what to check next? I am going to open the door panel tomorrow and see if any thing has come loose. Thanks.

Jeremy5848 · #2 01-27-2007, 10:25 PM

My 123 trunk will open with the key, whether the vacuum system is working or not. I don't know your car (is that a 126?) but I would think that Mercedes would have made a manual override for all vacuum locks.

#3 01-27-2007, 10:51 PM

Quote:

Originally Posted by Jeremy5848

My 123 trunk will open with the key, whether the vacuum system is working or not. I don't know your car (is that a 126?) but I would think that Mercedes would have made a manual override for all vacuum locks.

I agree you should be able to unlock the trunk with the key, but if it's like my cars considerable fiddling around may be required. On the occasions when I've had to use the trunk key lock due to vacuum problems it has always taken several attempts to get the correct sequence of pushing and turning the key.

crashone · #4 01-27-2007, 11:33 PM

Ahh yes the key, I have not changed the tumbler yet

The key will not turn the lock. I have taken it apart before and tried to clean it out to no avail. The dealer needs ~$85.00 for that tumbler also. I think replacing that tumbler has just moved up on my priority list pretty quick, as soon as I can get the vaccum to work so I can get to some of my tools, that are safely locked in the trunk now!

At least the car starts and shuts off fine so far.

sixto · #5 01-28-2007, 01:49 AM

Somesome suggested applying pressure to the actuator line in one of the doors. If there are no big leaks in the system, that might unlock the trunk. I haven't heard that anyone's actually succeeded.

Sixto
93 300SD 3.0

winmutt · #6 01-28-2007, 09:49 PM

Quote:

Originally Posted by crashone

Ahh yes the key, I have not changed the tumbler yet

The key will not turn the lock. I have taken it apart before and tried to clean it out to no avail. The dealer needs ~$85.00 for that tumbler also. I think replacing that tumbler has just moved up on my priority list pretty quick, as soon as I can get the vaccum to work so I can get to some of my tools, that are safely locked in the trunk now!

At least the car starts and shuts off fine so far.

While you have it out just replace the leaves and tell the stealership to stick it. If you cant take it to a locksmith who can.

crashone · #7 02-10-2007, 08:34 PM

OK today I had time to work on this. What I found out was that it seems like I had a bad door lock diaphragm in the passenger door. I plugged off that vaccum line and every thing works right. I went out and picked up a used one from the boneyard to replace it. Now I have another question..... This pod worked well 2-3 times and then started acting up, it will lock and hold vacuum fine but --It will stop unlocking and the whole system shuts down. Almost like there is not enough back pressure in the system. Does any one know what the culprit might be and where to look? Could this be a weak vac pump in the trunk? Thanks for all the help in trouble shooting this.

tobybul · #8 02-11-2007, 12:17 AM

I was gonna say you have a vacuum leak.... and those are usually at the elements (actuators). The diaphrams tear.

crashone · #9 02-11-2007, 12:16 PM

Any ideas?