i just overhauled the rear brakes on my 97 z24, new shoes, drums, wheel cylinders, etc...and now i cant get the rear brakes to bleed. i get fluid to come out but a lot of air too. the pedal was fairly soft before and the rear brakes were beyond shot but i never tried to bleed em before i put all the new parts on, so im not sure if they were even "bleedable" before i changed stuff and the pedal definately feels softer now. i bled em for about an hour and a half with a buddy the old fashioned way going through two of the large containers of brake fluid and then today i bought one of the handheld vacuum pump deals (mityvac) and went at it for about another hour or so by myself. same thing lots of air and not much fluid. the front brakes bleed just fine. all of the lines look fine and i dont think anything is leaking. i dont see any noticable puddles nor do i lose brake fluid in the reservoir. so im not sure where else to go now. the only thing i can think of is possibly a bad master cylinder or the slim chance that the two new wheel cylinders are faulty. and im not leaning towards the master cylinder because i can pump up the brakes with the engine off and they drop about and inch then are tight and the pedal doesnt go any further towards the floor. i took the brake lines outta the wheel cylinders again today and put teflon tape on them and the bleeder screws too. soooooo thats where im at and i need some advice from some pros haha. let me know whatchya think

so i finally got em to bleed today. i re- teflon taped everything and tried bleeding with the car running. im not sure if the car running is what made the difference or just coincidence, but they work now and the pedal feels much much better. still cant get the rear bleeder screw on the abs module/master cylinder dealio to bleed with no air bubbles but like i said the brakes feel good and i think im gonna quit while im ahead.

...just in case anyone was curious

I was just gonna ask if you tried bleeding the master cylinder. If they get too low on brake fluid, they definately need to be bled.