The recommended fluid for a 1965 GTO non-Power Steering box is typically a light hydraulic oil, such as Type A automatic Transmission Fluid. Some sources may suggest using a dedicated steering box fluid or a 50/50 mix of automatic transmission fluid and a lightweight motor oil. It’s important to check the owner’s manual or consult with a classic car expert for specific recommendations based on your vehicle's condition and usage.
DOT 3 power steering fluid.
Ford type F
Type F
Do NOT use transmission fluid in your power steering. It is designed for automatic transmissions, and a few rare manual transmissions only. (1965 Plymouth "Slant Six" manual transmission used automatic transmission fluid). In most Chrysler products made after about 2002, ATF is what they use for power steering fluid.
Ford automatics of that era use Type F fluid. Incidently, so does the power steering unit.
Type F transmission fluid unless it's been rebuilt. Then it would be Dexron III or whatever fluid the builder recommended. Mine it was Dexron III
Originally MF recommended TYPE A oil MF issued a service bulletin in 1965~1966 In this bulletin MF recommended M-1129A, same as in the transmission.
In the fluid chamber
DOT 3 is the fluid for you.
Automatic transmission fluid
To install a power steering pump on a 1965 Ford Falcon, first ensure the engine is off and cool. Begin by removing the old pump, disconnecting the power steering lines and any mounting bolts. Position the new pump in place, securing it with the mounting bolts, and connect the power steering hoses. Finally, fill the pump with the appropriate power steering fluid and check for leaks before starting the engine.
Begin by removing the hose from your power steering cylinder. Remove the power steering cylinder retaining bolts. The power steering cylinder will come off.