1981 380sl 107 power door locks
 

Greetings,
Got a 1981 Mercedes with a vacuum actuated power door locks that leak vacuum like crazy. I put a gauge on at the firewall on the yellow line and could not get it to hold any vacuum. The door locks work fine with the car running, however when you shut it off they don't work (or work but very briefly), is there a particular place where I should start looking for leaks?
Is it worth it?

Thanks in advance.

With 25 year old rubber vacuum diaphragms in the passenger door, trunk lock & gas flap...start by replacing ALL 3 of them!

BUT first make sure that the vacuum check valve under the hood HOLDS vacuum & also the vacuum storage tank under the fender.

canister
 

The vaccum storage holds vacuum fine and all the check valves have been replaced. So I guess I will start yanking the door panels and see if any of the door lock actuators hold vacuum. I just didn't want to have a broken door panel and was wondering if there is a place in the dash to check first.

Thanks.

Checking & OR replacing the gas flap OR trunk lock diaphragms require no door panel removal...ONLY the passenger door requires that removal.

gas flap?
 

What's a gas flap?
Are you saying I can replace the driver's lock actuator without pulling off the door panel?

drivers door doesn't have a actuator.... only a master switch & they rarely go bad.