It is the Toyota Power Steering Pressure Line Hose that transfers the high pressure hydraulic fluid from the power steering pump to the steering box. This is where it can be accessed by the driver so maneuvering the vehicle is much easier than with manual steering.
The construction of the power steering pressure line hose is metal at both ends joined together with reinforced polymer tubing. It can be located running across the front lower section of the engine compartment under the hood of your Toyota. Its diameter is much smaller than that of the coolant hoses so it can transfer the hydraulic fluid this short distance without any of the pressure diminishing.
Since the hydraulic fluid in the Toyota power steering pressure line hose is so great, any rupture in the polymer line will cause a rapid lose of fluid in a very short period of time. When this condition is present, the driver of the Toyota will almost immediately notice a change in the steering of their vehicle. This is the stiffness in the steering wheel when a maneuver is attempted.
An inspection of the power steering pressure line hose should be done when there is a load on the system. This allows for the inspector to see the rupture as a fountain of fluid emanating from the power steering pressure line hose. If the reservoir in the power steering pump is low, it should be filled so the test can be carried out properly.
When the rupture in your power steering pressure line hose is identified on your Toyota, the only solution available to the owner is the replacement of the component. A patch on the hose cannot work because of the high pressure the hydraulic fluid will be at in the hose.