Can you use it?

he action of the power steering system is driven by the power steering belt. Like any other belt in your vehicle, the functionality of a system starts and stops with the belt. 

The steering rack, which is part of the rack and pinion, is the primary part of your steering assembly, and works in conjunction with the power steering system. Steering racks can grow damaged over time as they develop wear and tear, and when they do, they make it much harder to steer your vehicle.

Contrary to the other answers, steering a car with failed power steering is quite possible. It is difficult at low speed, and extremely difficult when stopped, but it can be done. You'll build your arm and chest muscles doing it for any extended period of time.

My '87 Mercury leaked power steering fluid like a save, and I was still able to drive it - even pulling a trailer - without the hydraulic boost.

There some moments when the steering wheel becomes stiff and hard to turn. From irregular servicing, lack of fluid oil to low tyre pressure or bad wheel alignment, any of these could be the cause. ... Under normal circumstances when the car is in good condition, the steering wheel is always flexible when turning

Some vehicles, particularly those manufactured between the years 1980 and 2000, can use automatic transmission fluid (ATF) as a substitute for power steering fluid. If the power steering fluid in your vehicle has a reddish or purplish color, it is very likely ATF.