I promise... I've searched, but couldn't find this little tidbit...

What is the "normal" vacuum on the door lock tubes? I'm only able to get about 5" Hg on either of the lines with my Mityvac. Would someone measure yours for me?

__________________
Brian

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Sometimes the only choices you have left are bad ones.
Agent Broyles (Fringe)

Seems like I got something between 15 and 20 when I fixed mine.

15-20 is normal while idling or right after shut down. Every time you use the locks you lose a bit of vacuum from the reservoir. When did you test the vacuum ... during idle or after shutdown? Also where were you testing ... before or after the firewall? If before the firewall were you reading after the yellow check valve? I ask because the green one is a reducer and drops the vacuum to 5 IIRC. (it also isn't part of the central locks but I'm just checking )

__________________
Chad
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys

The "Y" side of the yellow check valve was completely disconnected and I was checking from there back. The 5" was not static, that was the max I could get pumping the Mityvac; it bleeds down to nearly 0 in about a second.

__________________
Brian

_________________________________
Sometimes the only choices you have left are bad ones.
Agent Broyles (Fringe)

So you were trying to pull vacuum on the single tube that leads into the yellow check valve? Or were you trying to pull vacuum on the green stripe or the blue stripe tube? Was the vacuum tree closed everywhere else?

What you're describing is a MAJOR leak in the system and you can't pull a vacuum.

Also if you disconnected the tubes and bled the vacuum all out, you could be trying to pull a vacuum on the empty system which requires about 150 or so pumps on the Mity Vac to fill the reservoir.

__________________
Chad
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys

15-20 is normal, it should be the same in the system as it is at the vacum pump. Sounds like you have a ruptured diaphram in one of the doors. When you say you can only pull the 5", is that both in the lock and unlock positions on the drivers door? Like they said above, you can isolate lock and unlock by the red or green striped yellow vacum lines in the car. another way you can maybe find leak quicker is to put approx 10 lbs of air pressure into the system. I wouldnt go any more.. and listen around the doors and trunk area for an air leak. Like it's been called here before.... vacum is just negative wind.. soo positive wind in the same pressure range will not hurt the diaphrams in the system.

First, thanks for all the info!

Now, I just checked again. Took out the yellow T check valve.

Mityvac directly to solid yellow tube
both left doors locked = 12" max and back to 0" in 1 second
driver's door unlocked = 5" max and back to 0" in less than a second

Mityvac directly to yellow tube with brown(?) stripe
both doors locked = 14" and held after 100+ pumps of the Mityvac
after 200 pumps still held at 14"

So, now what are the most likely culprits?

__________________
Brian

_________________________________
Sometimes the only choices you have left are bad ones.
Agent Broyles (Fringe)

Ok, the fitting I was using had a leak and I figured out that the one with the stripe is the "vacuum supply tank". (I finally got my $20 CD from Mercedes Classic: section 80-260 was particularly helpful.)

So... I just checked again. Took out the yellow T check valve.

Mityvac directly to solid yellow tube
all doors locked = 23" max and held
driver's door unlocked = 5" max and leaked down slowly (but steadily)

Mityvac directly to yellow tube with stripe
after about 200 pumps held at 23"

It looks like I've got a leak in the driver's door "vacuum switch" for the unlock function. I'll test the switch and attempt to adjust it (per 80-200) before replacement.

__________________
Brian

_________________________________
Sometimes the only choices you have left are bad ones.
Agent Broyles (Fringe)

I think that a more accurate assessment would be that you have a leak in the "unlock" (green stripe) portion of the system.