What is the primary method of bleeding a power steering unit?

The primary method of bleeding a power steering unit involves turning the steering wheel left and right repeatedly. This method allows any trapped air within the power steering system to be expelled as the fluid circulates. When the wheel is turned, the power steering pump creates movement in the fluid, which helps push the air out of the system and into the reservoir.

As the steering wheel is turned from lock to lock, it encourages movement in the fluid and promotes the formation of aeration, allowing air bubbles to rise to the top and escape. This is a simple and effective technique that can be easily performed without needing specialized equipment.

Other methods, such as draining the power steering fluid completely or using a vacuum pump, are not the primary techniques employed for bleeding the system. Draining fluid is more about maintenance or replacement rather than bleeding air, while vacuum pumps are often used in other systems but are less common in power steering applications. Running the engine at high RPMs does not effectively help in removing air from the power steering system and could potentially lead to other issues, such as overheating the fluid.