i was working on the trans linkage last week. i'm small, so i didn't really need the car raised- but a little extra room is nice. so, i was using a gm goodwinch jack from wally world $16.88. under the car, and snap- the car landed on the jackstand. i don't think the hydraulics failed, i think the 2 metal bars that raise it bent and broke loose. the jack was rated for 4000 lbs and i only had it raising 1/4 of car. my head would have been crushed like a melon if i hadn't had the jackstand. this is one time i'm glad i listened to my dad, he was the one that taught me to use a jackstand even with the jack. i was a little un-nerved but ok. and yes, i know that is a small cheap jack, but don't need a jack very often.