Anyone ever heard of a extended boom suddenly slamming down about 3 feet as you are booming up ? I didn't think this could happen. I'm no mechanic...
If nothing is broken inside the boom the cylinder can cause that. If the seals are bad hyd oil bleeds off. Since there's no pressure on that cylinder untill you boom up you can't tell if it's bled off untill it slams in.
I would be interested to know if this has happened to anyone else - i was just glad the load was suspended at the time and so I was fortunate. But it could have been BAD...