There is all kinds of rigging, but you should have either a lever or a cable which operates the PTO. It should be attached to the pto which is bolted to the transmission. If it's working, you should be able to step in the clutch, pull the cable and the PTO should engage. If you let the clutch out a little bit, you should hear and feel the PTO turning. The pump should have 3 positions on it. Raise, hold and lower. You will want to replace the bad line. Most automotive or farm machinery dealers can make up hydraulic hoses. I'm not sure what other cable you are talking about unless it operates the tailgate. Usually there was a lever on the side of the dump bed where a driver could reach it through the window. Someone may have rigged up something to automatically open the tail gate to make sure the tail gate got opened. Dumps will turn over if they raise without the tail gate open. Many dumps now automatically open the tail gate with air when the dump goes up. I prefer to have my drivers to get out and look where they are dumping and manually dump the suspension and open the end gate.