Suggestions for Filling Your Power Steering System
Use Manufacturers service manual for fluid and filling. If you don’t have the service manual, these recommendations have been developed from years of experience with 1950s and up power steering pump/gearbox combinations.
Never use sealers, silicone or teflon tape on fittings
Fluid Type
Use the manufacturer’s recommended fluid. 1950s, 1960s, and 1970s GM and Ford products can use the Dexron III equivalent FORD type “F” ATF.
Modern power steering fluids are backwards compatible back to the 1960s and up.
Filling Procedure
Fill the pump’s reservoir (tires on the ground)
Start the engine for a few seconds and turn it off (do not turn the steering wheel.) Check and refill the reservoir.
Repeat Step 3 until the reservoir remains full. (If you turn the wheel before the system is full, you can cause an “air bind” in the pump pressure/flow control valve that will result in diminished or NO POWER ASSIST to the power steering gearbox.)
With a full reservoir, start turning the steering wheel SLOWLY after starting the engine. If you hear the pump growl or moan, stop turning the wheel and turn off the engine. Check fluid level. Start the engine again; slowly move the steering wheel back and forth to expel the air.
Check the line for leaks. Confirm the hoses aren’t rubbing against other parts in the engine bay.
Air should be completely expelled within a day or 20 miles of driving. If you see fine air bubbles in the system after this time, there can be air sucking into the system. Check your return line clamps and/or replace old hoses.
Saginaw Pumps Only: In the event you experience an “air bind” (this is rare if the above instructions are followed) remove the pressure hose from the back of the pump. Then push a very thin straight pick into the pressure port hole to release the stuck flow valve. Push it in about 6 times. You should feel the flow valve spring pushing back at your effort. Reattach the pressure hose and refill the reservoir. This should correct the problem. A 5 second video showing the process is here.
A printable version of this page is here.