454 valve lash adjustment question

[Mr. M3]

I was working on adjusting the valve lash on my 77 C30 454, and came to an odd point where if I adjusted the play out of 1 rocker, I could wait for about 10 seconds and the rocker would have play again. I am assuming that the lifter has released some fluid, but I am uncertain. I adjusted one down 8 times to see if I could get the play out completely, and it did lose play after that many times. I set the rockers to the point where they have no front/back or side to side play. At this point I am going to pause and see if I am doing this correctly before I go trying to start (potentially blow up my motor) and test it. Any input is appreciated! Thanks in advance!