Hello,

I got a great deal on professional restoration to get my 85's floor rust fixed. All done and like new!!!

The problem now is that I need to chase down a minor vacuum leak in the door locking systems. In doing this, Id like to do a rigorous analysis of what the state of all the vacuum systems are in my car.

As a result, I went out and started pulling vacuum on things - couldnt get the lock section to go better than 5 inches, and then it would immediately creep up, not to zero, but close.

The funny one was the ACC unit, the gren line with the yellow tracer. I pulled 25 inches of vacuum on it, and then it immediately bled to about 15, where it sat relatively steady. There was some loss in time, but it was slow.

As a result, I am curious if there is a guideline for what vacuum level each line should sit steady at, and from 20 or 25 inches, what the typical bleed rate should be, and where the loss in vaccum should stop.

If the system sits at 5 inches, and only needs that to operate, and Im worrying about 15 or 20 or 25, then Im just wasting time. Similarly, if an ACC unit always bleeds vacuum after making its change, or there is another phenomena involved that dictates vacuum loss or ultimate steady state vacuum level, it would be nice to know what others typically encounter.

Any insight in this regard would be most appreciated.

Thanks!

JMH

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)

Sounds like you have a leak in you locking system on your door locks. In a perfect system you could pull 15" on either the lock or unlock side of the door locks and it would hold it for ever. I usually pull vac and let it sit for a minute or two. Then see how much it drops. If it doesn't drop much I don't worrky about it. But if I can see it falling something is leaking.

I've always used 15" Hg on most of my vac operated stuff. There is no need to go much above 15" because the vac pump only creates up to 25" anyway, and most of the vac systems in these cars don't get the full vac due to orifaces that reduce the volume.

__________________