Jammed steering

[Temala]

I have a 1991 Prout Event 34. Recently, while sailing with a nice 15 knot breeze off the starboard beam the wheel suddenly jammed full to port. Luckily, we were able to drop anchor while we checked out the problem. The rudders were inspected and found to be okay. Upon inspecting the hydraulics under the transom we found the ram of the hydraulic thoroughly jammed. We removed the connections to the steering and installed the emergency tiller which enabled us to make it back to our swing mooring. Since then I have tried to bleed the system as well as "encourage" the ram back into the cylinder (with hammer!) nothing has worked. Has anyone else experienced this problem and how was it fixed?