Turtle,

You need to complete multiple test, first being a pressure test at the steer and hydraulic valve. Steer pressure should be about 1800 psi, lift pressure about 3000 and tilt or aux functions about 2300 to 2500. Replace pump or check replace relief valves. If all pressures are good, check tank for dilution rom air. Should see a lot of bubbles in the tank. Suspect pump has failed or broken metal line at pump. Good luck.