The failure happened where the pipe goes through the bulkhead from the big locker to under the galley locker. After taking out the failed pipe I checked the hole in the bulkhead which the pipe goes through. The surface was very sharp with prickly bits of fibreglass and the pipe did not have anything to protect it. Before inserting the new pipe I filed away the spiky bits and put a good sleeve of plastic hose round the pipe where it goes through the bulkhead.
I suggest that other P31 owners climb down into the big locker and take a look for wear on the hydraulic pipe at that spot.
On your suggestion Pat ,we have checked the hydraulic cable on Pegasus and discovered it it was on its last legs.
Upsons boat yard has replaced the cable and checked Sula, also a Parker31 ( ashore for the winter next to our boat )She also had the same problem and now we have both been sorted with new cables
Very many thanks to you Pat