There is air in the power steering fluid.

1. Inspect the power steering system. Refer to Power Steering System Test .
2. Bleed the power steering system. Refer to Power Steering System Bleeding .

There are air bubbles in the fluid.

1. Inspect the ambient temperature for an extremely cold temperature. Refer to Fluid Specifications .
2. Inspect the power steering fluid level. Refer to Checking and Adding Power Steering Fluid .

The fluid level is OK but still foams.

1. Remove the pump. Refer to Power Steering Pump Replacement .
2. Inspect the soft plug for cracks.
3. Inspect the housing for cracks.
4. Replace the pump as needed. Refer to Power Steering Pump Replacement .

The internal pump is leaking.

Inspect the power steering pump for leakage.

Refer to Power Steering Gear and Pump Leaks .