Hello everyone I bought a 731 half way taken apart and am trying to fix. I got the little duetz running good. I have all the hoses In the correct locations check valves in. The problem is the drive. It feels weak going forward and back and doesn't turn just growls really loud. I have changed the bronze suction filter checked all the replenishing valves, checked neutral charge relief valve and did a pressure check at the port block. 90 to 110 psi in neutral and moving on jackstands. What else can be tested before pulling and tearing down the hydro unit?