Tractor Repair: 1974 case 1070 agri-king, torque limiter, drive shaft

Question
My tractor was running fine down the road until I lost all hydraulics and no gears won't go forward or reverse. I tore apart the trans but no damage what so ever but the engine runs fine. Could it be my hydraulic pump has gone or maybe a valve is open in the hydraulic pump?

Answer
Hello,

  I am assuming this tractor has a powershift transmission instead of a hi/lo range transmission.  If the oil level is good and the filters are clean, it's possible that the pump or the pump drive shaft has failed.  There is also a suction screen at the bottom of the pto cover inside the rear end.  There is no relief valve in the hydraulic pump.  The relief valve is on top of the remote valves under the fuel tank.  The power steering relief valve is in the brake valve.  On the very early models, the hydraulics would quit working if the torque limiter on the flywheel failed.  On the later models, the pump drive shaft is not driven by the torque limiter.  Not sure on a 1974 model, but I would think it would be the later style.