Had a Hyd failure in a 206. Leak which made it much harder to fly vs a pump fail. (pull the hyd CB to make sure it is not just a switch failure...pulling the CB will restore pressure if it is an electrical problem.)
Had 2 in a Astar. First order of business.. turn off that +*^% horn so you can think.
205...,remember that you should never lower the collective below 35 PSI because it will be a bitch to pull it back up.