Low power steering fluid

Add power steering fluid.

Pump belt is slipping

Refer to Drive Belt Replacement in Engine Mechanical (6.0L, 7.0L) or Drive Belt Replacement in Engine Mechanical (6.5L).

Sticky flow control valve

Replace or clean the control valve.

Insufficient pump pressure

Refer to Power Steering System Test .

Faulty gear pressure relief valve

Replace the faulty gear pressure relief valve.