You probably need to add power steering fluid.
ball joints could be bad Did you make sure you got all the air out of the power steering system?
check the power steering fluid level and the power steering belt
You either need power streering fluid or a power steering belt.
Power steering pump failing.
Power steering belt slipping? Power steering pump bad? Steering rack worn? Suspension parts worn?
Hard power steering means there is little to no fluid left in the system. The power steering system should be flushed and checked for leaks.
power steering is easier and you do not have to turn the wheel as hard as manually.
A steering wheel may be hard to turn because the power steering fluid might be low. It also could be that there is problem with the power steering pump.
Low on power steering fluid. Loose or missing drive belt. Faulty power steering pump. Faulty power steering box.
Power steering fluid helps your steering wheel turn easily. If you have dirty power steering fluid, it may be hard to turn your steering wheel while driving.
The characteristics of a power steering hose is it is a hard rubber thick enough to hold the fluid needed to make the power steering work.