How long should vacuum locks work?

[78240D]

Hey everyone. My question is, after shutdown, how long should the vacuum locks still be able to work? It's been 6 days and today they didn't open with the driver's lock.

Thanks all!

[Chad300tdt]

Mine hold vacuum for for at least 2 weeks. That's the longest I've gone without using them. If you don't plan to leave it sit that long again, you may be able to get away with postponing repair. In any event you should get a MityVac if you don't have one. Good luck.

The system has to be pretty tight to hold for a week. At the moment, mine is losing vacuum someplace and only lasts about one day. Mine has held for a full week when nothing was leaking. Finding a very small leak is a PITA, but I'll have to do it one of these days.

[JimFreeh]

I can get at least a week out of my 83 300D. Last time it was ten days at the airport and they still popped right up when I unlocked it.

Jim

[79Mercy]

I haven't ever let it sit longer than a 2 weeks, and they held for the 2 weeks that it did sit.

[cphilip]

Hold without using them at all?

I been testing mine out and not just for length so far but for length plus operation. So for three days I unlocked and relocked at least twice each day and today, fourth day, they would not unlock. All without running the motor so residual vacuum is all it had. Total was 8 locks and relocks over three day period and failed to unlock morning of the fourth day. I would guess, unattended and unused it would have lasted longer.

I think thats good for an old 83.

[Chad300tdt]

I believe you lose a little vacuum with each lock/unlock.

[79Mercy]

^^Yes you do because you are draining the pressure in the vacuum tank.

[Hatterasguy]

I can let the SDL sit for months and they still work perfectly.

Originally Posted by Hatterasguy

I can let the SDL sit for months and they still work perfectly.

At least until the battery goes dead.

[Mark DiSilvestro]

WhenI got my 82 (built late '81) 240D, the locks would work for 2-3 days. Now I notice its maybe one day, and I need to lock the driver's door after I get in or sometimes it won;t build up enough vacuum to shut off the engine. But thats OK, so long as I can get them to work while I'm out with the car.

Also something I've noticed recently, while scavenging used vacuum lock actuators at a Virginia Beach Pick-N-Pull - the external seals on the 1983 vintage actuators are some type of red silicone, that doesn't seem to dry-rot and crumble like the black rubber variety used in my two 1981-built 240Ds. Perhaps the '83 and later actuators are more durable.

Happy Motoring, Mark