Coolant bleed issue

OK, so I am trying to refill the system on my 99 C2 and using the Airlift vacuum tool sucked to 22" but was only able to get about 2-1/2 gal back into the system before the vacuum gauge hit zero. So I now have a full-to-the-neck reservoir and obviously cannot create a vacuum again without sucking the coolant back out. My question is, is there a place in the system I can open to release more air? I tried cracking the upper rad hose on the pass side, but coolant is there, so thought I'd ask here before popping off more hoses to see if there is a place to do this. Driver's side, perhaps? Or, do I need to drain what I can back out and try the vacuum tool again?? Thanks for any suggestions here!

How much did you take out?

Yes, how much did you take out? 22" is about all of the vacuum that I can pull, just did it today, the system was close to empty (almost 5 gallons removed). If you only removed about 2.5 gallons, you are okay to start the car, the level should go down, then add by hand, let it warm up a bit, put the cap on and take it for a short ride around the block with the heater on, come back, let it cool a bit and see what the level is and add coolant. If you took close to five gallons out, please let us know what else you did to the car during this service.

OK, so this is a little embarrassing as it was almost a year ago when I pulled the eng/trans to do some "fi-it-before-it-breaks" work on the car...Vario cam pads, AOS, Starter, IMS, clutch, water pump, and lots of little stuff. Since being asked the obvious question of how much I took out, I'm not completely sure what we wound up with. I assumed (dangerous, I know) that most all of the coolant would be lost removing the engine. However, since there is presently fluid at the front rad hose, perhaps it is indeed close to full. Or close enough to finish off with the run and burp process? I went back out to the shop and discovered in my mess a catch bottle (5 gal) with old antifreeze that may have been my drain out from the engine pull.....it's only 1/2 full! Is it reasonable to think that 2-1/2 gal or so remained in the system after pulling the engine??

If you only undid the plug in the coolant manifold at the back of the engine, it's about 2.5 gallons. If you then pull the main hose off the thermostat housing and blow air through the expansion tank, that's the next 2 gallons and the last 0.5 gallon is in the heater core. So if you didn't pressurize the system, you only got 2.5 gallons. FYI, after I do the vacuum fill the first time, before I even start the car if the coolant level drops low after taking the vacuum off, you can put it back on and draw a much lower vacuum, just throttle the valve. If there is air pockets, it will continue to pull air out of the system, but you will only get to 10 or 15" of HG, based on how much coolant in in the system. Review this: https://rennlist.com/forums/996-foru...pump-tips.html

Yeah, so water pump, t-stat housing all pulled off and the rear drain plug + 2 water hoses to the front pulled, but no pressure applied, so I'm gonna guess that I only drained less than 3 gal. I think we will be ok with run & burp....thanks for the input here, just wanted a bit of re-assurance!

You'll be good! Let us know how it turns out. If you read my other thread from today, I had to burp and add 1.5 liters and then 0.75 liters after a few spirited drives today.