hydraulic lifter help
 

I was just installing my first hydraulic roller lifters like I have many hydraulic lifters and 3 of them have made a popping sound and the plunger is now stuck down. They are Comp Cams retro-fit on a small block chevy and the cam lift is around .560. I adjusted to zero lash and then 1/2 turn. They are brand new soaked in oil, but not pumped up.

Daren