Sorry SRM,I misread your previous reply,you did use a 12 ton,why did you use a vice to hold it?
I had some dificulty in the beginning with my push pin leaving the scene at warp factor 9 after it slipped,skeered the caca out of me.I fixed the problem by using a very short pin,made from a 1/4" hex driver bit.I made sure it was square on each end by removing the little bevel that helps it find it`s way into a capscrew.I made darn sure the pin was pushing straight down and I slowly cranked up the pressure,didnt seem like it was going to give so I followed imacbo`s advice and let it sit,I had a beer and a cigarette then I put a cheater bar on the jack handle and gave it a couple more slow pumps.
POWWW!!! the sound made me jump,but the thing budged,a little more pressure and it came sliding on out.