Hydraulic System Pressure Test

Connect a pressure gauge between steering pump and steering gear. See Fig 1 . Bleed any air from system.

Fig 1: Pressure Gauge Test Set Up Put gauge set valve on gear housing side.
Open valve on gauge, start engine and turn steering wheel back and forth to increase fluid temperature. To measure fluid pressure generated by the oil pump, completely close the gauge valve for 15 seconds and increase engine speed to 1000-1500 RPM.
NOTE: Leaving gauge valve closed for more than 15 seconds will increase fluid temperature and could damage the oil pump.
To measure the fluid pressure generated at the gear housing, first open the gauge valve completely, increase engine speed to 1000-1500 RPM and turn steering wheel all the way to the left and right.
Do not keep steering wheel fully turned for more than 10 seconds. The correct gear housing fluid pressure limit is 924 psi (64 kg/cm² ) at a temperature of 122-140°F (50-60°C).
If the oil pump is defective, it must be replaced as a complete assembly.

Fig 2: Exploded View of 626 Gear Assembly