Racerunner 2.0 Rebuild Help

Im in the process of rebuilding the 2.0 racerunner sway a way coilovers for my tacoma. And maybe someone would know but , ive seen diffrent levels on how much oil i should put in it. ive heard 1" from top and 1/2" and 2" from top. And when you push down on the shock when charged it should cycle smoothly. I cycle one shock that u just took the spring off of and right when it ends its stroke about 1" before it decompresses fully it goes really fast and makes a sucking noise, normal? the one i just rebuilt you push in and decompresses all the way smoothly at a decent speed. Any shock builders can chime in?