The primary function of the power steering rack is to transmit the steering force applied by the driver through the steering wheel to the wheels. This transmission process seems simple, but it actually involves complex mechanical and hydraulic conversions.

Steering fluid is required for Hydraulic Power Steering (HPS) and Electronic Hydraulic Power Steering (EHPS). This is because these systems rely on hydraulic fluid to generate pressure to assist in steering operations. In Electronic Power Steering (EPS), steering fluid is not required.

Manual steering racks are significantly different in structure from hydraulic steering racks, so direct replacement is not always possible. Installing a manual steering rack may require modifications to the vehicle's suspension system and steering column to ensure compatibility between the two.