Claas 700 liner rake lift problem

I'm trying out a Claas 700 twin rotor rake that a local dealer has on consignment and I'm having a problem getting the hydraulics to work. The front rotor will raise and lower fine but the rear rotor won't lift at all. The dealer wasn't given a manual and isn't a Claas dealer, so they aren't a whole lot of help. Any ideas?

Claas 700 liner rake lift problem