most lifts today do incorporate the steering function into the hydraulic system. It operates off the auxillary ports of the hydraulic control valve and is controlled by what they call a priority valve that diverts pressure to the steering cylinder when it is called for when turning the orbitrol valve (steering wheel).

- i would first check the auxillary pressure on the hydraulic system, make sure it is at the correct pressure and also remove the relief valve and make sure it is in good working order.
- then find the priority valve and make sure it is not sticking (removal and dissassembly required for this part).
- also check the orbitrol valve there could be a problem there causing the hard steering, in some cases the orbitrol valve has a pressure relief valve on it, it can be removed and checked for broken springs etc.
- lastly you can check the steering cylinder and make sure it is not leaking or bypassing internally.

some of the most common issues with steering generally winds up being a faulty priority valve or some kind of issue with the orbitrol valve.

good luck