How common is "working" automatic locks on older Mercedes? (meaning 91' and older)

[86560SEL]

First of all- when (if at all) did Mercedes switch to electric powered door locks? Since our "clocks" thread turned out good, I thought I would post another question about what "works".

I am assuming that the automatic door locks on my 1985 are vacuum operated? I have heard of lot problems with these locks on the older Mercedes, but wondering just how common the problems with this system are. How many here have problems with this system? When they do fail, what is usually the problem?

So far, the ones on my 85' are still in perfect working order (knock on wood) and I hope they stay like that. Seems like when my doors lock, it also locks the gas lid, as well as the trunk, which is normal as far as I know. I have not really taken the time to read my newly acquired owners manual yet.

Also, just for a quick answer (incase I do not have time anytime soon to look at it), is there anyway you can lock/unlock the doors while driving? I am still trying to get familiar with these buttons on this car, but really do not see anything that looks like a door lock button. I just thought of this- perhaps if I just simply press down on the door lock on the door, then they will all lock? I may get a "DUH" answer from this. If that is the case, anyway just to unlock one door instead of them all?

I will try it tomorrow.

Thanks!

[speedy300Dturbo]

The vacuum locks that are activated by the electric pump are MUCH less trouble prone than the early ones that relied on stored vacuum generated by the engine or engine mounted vacuum pump (for diesels). Much of this is because the later locking system is independent from the rest of the car's vacuum ancillaries. Also, the later system has half as many vacuum lines running through the car, because there is only one line for lock and unlock, while the earlier system needed two. Overall, the switch to the electric vacuum pump was a HUGE improvement.

[Two560Two]

The vaccum system for my 560SEL and 420SEL are still in perfect working order. I hear many problem with the system though but they never happen to me. I don't know why mercedes went with the vaccum system instead of electric lockers? maybe they didnt like how loud electric lockers sounded. The only way to lock and unlock the car from inside is to just either pull up or press down on the 2 front lockers

[86560SEL]

Thanks, so does my 85' model have the "electric pump"?

[86560SEL]

Yeah, the early power door locks in American cars were very noticable. My 73' Pontiac Grand Ville has the optional door locks and you can hear them from a mile away! Those are some powerful locking motors on those cars.

Now I think the earliest auto door locking systems on American cars were also vacuum operated, rather than electric. I think that most American makes from 1970 and back (at least GM) used the vacuum locks, until 1971. My 1969 Chevrolet Caprice also has automatic door locks that run on vacuum. However, they are not in working order at this time, but the power windows still work quickly and perfectly. Same for the optiona power windows in my 1973 Pontiac. Strange that the power windows on the older American cars still work fine, but the newer cars (especially GM cars) last onle a couple of years before something goes on the fritz. My moms 97' Oldsmobile currently has a LF window problem. It is very slow and will only go up and down at small intervals. I think the regulator is bad.

Originally Posted by Two560Two

maybe they didnt like how loud electric lockers sounded.

[neanderthal]

electric locks dont work under water.

[haasman]

It is my experience with the vacuum locks that when they don't work, it is usually just one thing. Often on some cars it is the the gas door lock.

Haasman

[1991 560 SEC]

Mine work.

Mine have not worked since I bought the car and I have so far been unable to pinpoint why. I suspect the aftermarket alarm/ keyless entry system from Brooklyn which was removed just before I bought the car.

[wbain5280]

Mine work fine.

[Nate]

mine doesnt, and its staying disconnected untill i can drop $200 and a few hours into the system...

but I'll allready have the system apart to fix my heater problem, i just dont have the $$ to do it all at once...........
Damn car audio stuff

~Nate

[A264172]

Mine stopped working... turned out to be bad power (+) to the pump... rerouted it and now they work again.

[meltedpanda]

mine are fine

[Fourings]

Locks worked fine on my '89 300 when I bought it and still do.
When I bought my '92 400 the pump worked fine, but the driver's door lock wouldn't operate without manual assistance. $50 later for a door lock actuator and they work perfectly.
If you have a door that isn't working with the rest you may have the same problem I did. Call the dealer and they will gladly sell you the actuator with the latch mechanism. That's how they sell it. Dealer quoted me in the neighborhood of $190. Local indy shop sold me the actuator for $50. Still painful as the part that fails is a $.30 silicone diaphagm inside the actuator that rips and could be replaced if the part was available.

[MikeTangas]

Mine work just fine on both the 560 and the 4.5.