The Power Steering Pump and Reservoir assembly is somewhat beside and below the Alternator by the Firewall on the Passenger's Side. Look down and you should see the hidden cap.....
Top of engine on the passenger side.
regular power steering fluid is all you need.
At th power steering pump reservoir.
Add fluid at the power steering pump reservoir. Rear of engine passenger side.
Just power sreering fluid. dextron 2 or 3
It probably needs steering fluid.
Power steering pump reservoir. Back of engine passenger side.
behind the alternator near the firewall about 3" down
the power steering resevoir, MAKE SURE the vehicle requires power steering fluid, some use transmission fluid instead. If your unsure take it to a lube center and ask them to do it you. In the 2004 Chevy Impala with the 3.8L engine, the power steering pump is a sealed unit. It does not require fluid to be added. Also if you have to replace it, it is not an easy job. The power steering pump is above the transmittion and behind the center of the engine.
In the master break cylinder
check the fluid level in the power steering reservoir and make sure it's where it should be.
If the Impala is the same as my 2001 Monte Carlo with a 3.8 L engine, the resivoir is on the pass. side way down low in back of engine compartment. You need a bright light to see it and it is very hard to get at!