Thanx Fellas ! .
As always, well considered replies .
Mark ;
He's in the passenger side foot well, after sliding the seat all the way back and removing the carpets you'll see a black plastic longitudinal cover you can gently lift up the inner side of to expose the various vacuum pipes and 'Y' connectors .
IMO, one should begin under the hood at the junction of the anti back flow (yellow & white) valve and two yellow plastic pipes, taking the driver's door apart is additional work not normally necessary .
The primary test is to see if the leak is in the locking system or the entirely separate vacuum resivoir in the trunk ~ one of the yellow plastic pipes leads from the firewall to the trunk and sometimes, there's a leak where this pipe enters the black plastic vacuum resivoir under the package tray .
The next stop is to test the other pipe in both locked and unlocked positions, this will tell you if the door's master valve is leaking, if so both positions will leak down, if one position holds vacuum and t'other doesn't you're likely looking at a bad vacuum chamber, the next step is to remove the passenger side carpet and address the various 'Y' connectors ~ expect them to have a serious hold on the plastic pipes but pay close attention to them after you've twisted and released them ~ if the pipes now slide in and out of the rubber 'Y' connector, it's BAD and is leaking no matter how slowly .
These slow leaks are why it's important to have a good quality vacuum pump ~ the new one I got yesterday doesn't hold vacuum over about 5", this isn't good .I've purchased two of the metal Harbor Fright vacuum pumps, neither ever held any vacuum whatso ever mking them useless for leak detecting .
I'm still rather sore from yesterday's efforts so I think I'll beg off to - day's planned works .
IIRC there are also 'Y' connectors under the passenger side rear carpet .
The trick is to not waste too much time on duplicate labor .