Vacuum system question

[tequilaiam]

Is there a place where air is supposed to re-enter the vacuum lines to simulate a WOT of a gasser? On a gasser, vacuum would be present when the thottle is closed but opening the throttle would allow air back in to the line and let the vac. modulator return to normal mosition. On the diesel, I presumed the vacuum valve on the IP cuts the passage between the vacuum pump and the modulator while allowing outside air to equalize the vac. mod.

I tested mine with a vac. gauge and hand pump. When I supply vacuum to one side of the valve and plug the other, the vacuum stays despite the throttle position. When everything is hooked up and I evacuate the line by hand, the vacuum slowly bleeds off. The modulator on the tranny holds vacuum just fine indicated the steel vacuum pipe is bleeding in a little air. Is this normal?

Everything seems just fine - the shifting is normal but I'm a little perplexed. If the vacuum system was totally sealed then the vacuum modulator could never return to normal condition....but I can't find anything in the manuals that says what allows air to re-enter the vacuum system.

Do I have a pin-hole leak somewhere AND a broken vacuum valve that are functioning normal together or am I missing something else?

 

[doghead]

If it shift correctly, leave it alone.