W123 Master door lock element failure? - Page 2 - PeachParts Mercedes-Benz Forum

Diesel911 · #16 10-15-2020, 12:10 PM

Concerning anything in the Trunk I just decided to disconnect and plug off the vacuum to there.
Now the Fuel Fill Cap door is always unlocked and I unlock and lock the Trunk with the key.
I also disconnected the Vacuum to the Doors so all is manual. No more BS with it.

My Mercedes is an 84 and my Volvo Diesel is an 82. The Volvo Diesel has electric door locks that I only had an issue with one time when the insulation on one of the door lock wires rotted away. I have also had zero power window issues with the Volvo. I cannot say I have had zero power window issues with the Mercedes and I have had to deal with the door lock vacuum issues maybe 5 times since 2007 and I bought the Volvo in 1992. So I have had the Volvo longer.

I also never had any US or Japanese Car with an automatic transmission that had the functioning issues like the Mercedes ZF transmission has and they had higher mileage. (My 92 Chevy Astro Van was a different story concerning the transmission. Started off fixing a front shaft leak and found the front Pump bearing was loose and that lead me to me finding more and more stuff that needed replacing and I rebuilt it. However, except for the front shaft leak I was working fine; just hidden things in side were going bad. Also the Previous owners used to tow a trailer.)

I would say the superiority of the Mercedes is mostly in the Engine and Fuel Injection System.

Diesel911 · #17 10-15-2020, 08:28 PM

Quote:

Originally Posted by gottarollwithit

After much trouble, I tracked down the leak the old fashioned way.

There's a total vac loss between the trunk actuator and the ft pass door. Usually vacuum stuff is pretty definitive, however i think i have a tank door actuator that's semi faulty. Trunk actuator, lines to tank lock, and lines to trunk lock all tested good.

Upon removal and inspection, the tank lock pod looks slightly warped and distorted, but when tested it holds vac on the lock side. BUT, when mildly holding down the locking rod, it is total vac loss. When not manipulating the rod, it moves and holds vac with a very small leak.

My theory is that the pod is physically distorted, thus mounts differently and causes the locking rod to drag on something when mounted. The dragging/resistance causes it to be a total vac loss, but since the pod is still sealing, it doesn't do it when unlocked.

Sound crazy??

When you get the new one please test it before installing it and post the figures.

gottarollwithit · #18 10-15-2020, 11:11 PM

How does one test a tank door actuator????

Mine holds vac no prob, just refuses to hold vac or move if it is in the zero position and encounters resistance

Diesel911 · #19 10-15-2020, 11:57 PM

Quote:

Originally Posted by gottarollwithit

How does one test a tank door actuator????

Mine holds vac no prob, just refuses to hold vac or move if it is in the zero position and encounters resistance

Sorry I got this thread mixed up with the main Door Actuator Thread.

There is no reason why you could not test the new tank actuator with your mightyvac to see if it holds vacuum in any position.

unkl300d · #20 10-20-2020, 02:15 PM

Block off the fuel door pod and trunk pod and then test the car for a while to determine if your gremlins are gone.
Keep it blocked off or else go for the fix.

good luck!

pj67coll · #21 10-20-2020, 02:29 PM

Quote:

Originally Posted by unkl300d

Block off the fuel door pod and trunk pod and then test the car for a while to determine if your gremlins are gone.
Keep it blocked off or else go for the fix.

good luck!

That's what I did on mine. One day I might go back and revisit the fuel door and trunk but I have no need for that functionality so I'm in no hurry.

- Peter.