The flow control valve sticks or is inoperative.

1. Clean the valve.
2. Replace the valve, if needed. Refer to Power Steering Pump Flow Control Valve Replacement - Off Vehicle .

Air is present in the fluid.

1. Locate the leak.
2. Repair the leak.
3. Bleed the system. Refer to Power Steering System Bleeding .

The fluid level is low.

Add power steering fluid, if needed. Refer to Checking and Adding Power Steering Fluid .

The pump belt slips.

Refer to Drive Belt Replacement 7.4L or Drive Belt Replacement 6.5L or Drive Belt Replacement 5.0/5.7L or Drive Belt Replacement 4.3L.

The steering gear or the hoses have damage.

Replace the parts, if needed. Refer to Steering Gear Replacement .