clutch slave cylinder headaches Options

[SAMIAM]

I have a bad problem with my clutch system but im hoping someone can help me out. I replaced the slave cylinder this weekend after diagnosing with a friend that it was leaking.When i was in stop and go traffic it would lose pressure and i had to pump the pedal up to drive. The car has 180k miles on it so ive had to replace the slave cylinder previously, as well as the master cylinder, and also a stage 3 act clutch.All three items were replaced about 2 years ago. With the old slave cylinder, if I held the clutch pedal in for a few seconds you could hear the pressure releasing almost like a burp.
So that's the history, here's where it stands now.
After replacing it, I have topped off the fluid and gravity bled the system. Air bubbles come out of the bleeder valve but no "drip drip" like I read on another forum. With a second person helping me I've tried to bleed the system like I had many times before with him pumping and holding the pedal in and me opening the valve to let the air out. The problem is that it will not build any pressure so that I can bleed it by pumping the pedal. The pedal is so free moving that a 2 year old could push it in with his thumb. I have literally pumped the pedal to the floor 40 times and then held it while he opened the valve and no fluid or air releases.
Do I need to somehow prime the system at the master or slave or what am I missing? Any input would be greatly appreciated.
Also, i have topped off the fluid throughout the process and do not have any leaks. I removed the battery and cold air intake to do the replacement so have not started the car. Is this the problem? A hydraulic system shouldn't need to be started to get it bled and working should it?

[Jamchell]

Looks like you may need to pressure bleed the system, I used to run into this problem frequently(mostly with Chevy S10s). I built a Gator aid bottle pressure bleeder which worked better than many kit bleeders that my co-workers had. Anyways there are air bubbles in there that are stuck to system components and the force of gravity isn't enough to push them through. There are a few companies that make tools which will help you, or you can make your own.

[SleekCelica]

I've always liked the vacuum bleeders. I had the same problem with my clutch, and then i used the vacuum bleeder, and it was bled and strong in 5 minutes. I put teflon tape around the bleeder screw, attached the vacuum hose to it, pumped it up, and then proceeded with the bleeding process.

[Jamchell]

Good point, vacuum bleeders are even better for most applications(they are less likely to cause damage). Just never could get em to do the job when I replaced a master on a chevy s10, which I used to do way too often IMO. I guess that's why I just break out the pressure bleeder on my cars.