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 .
3. Bleed the power steering system. Refer to Power Steering System Bleeding .

The fluid level is OK but still foams.

1. Inspect the power steering system for leaks. Refer to Power Steering Gear and Pump Leaks .
2. Remove the power steering pump. Refer to Power Steering Pump Replacement or Power Steering Pump Replacement .
3. Inspect the soft plug for cracks.
4. Inspect the housing for cracks.
5. Replace the power steering pump as needed. Refer to Power Steering Pump Replacement or Power Steering Pump Replacement .

The internal pump is leaking.

Inspect the power steering pump for leakage.

Refer to Power Steering Gear and Pump Leaks .