It's not just the Aerostars. The vast majority of Ford Motor Company
products had that same power steering pump.
The whine is caused by air in the PS system. Unless the pump is damaged,
the sound will go away when you fix any leaks, fill the pump reservior
properly, bleed it, and keep it filled. Bleeding it is simply turning the
wheel 3 times from lock to lock.
Try that and see how it helps you.
Power steering pumps are gear pumps. If it is whining it was most likely
run while low or with contaminated fluid, scoring the gears. The pump will
work, but it will always whine. One of my neighbors has a Toyota truck that
was run low but it is still working five years later. When he found out how
much a new pump cost for a Toyota, he would rather turn up the volume on the
Ma Ford drop shipped an adapter to many dealers.... this fits in place of
the PS pump cap and we use a vacuum pump to apply vacuum to the system. With
vacuum applied, run the engine and turn the wheels lock to lock.... it can
sound terrible for a few seconds but works in 90% of the cases I have seen.
Someone with a little ingenuity could probably jerry-rig one from an old
When one buys a used vehicle they can never know for sure how that vehicle
was used, or abused, or whether it was serviced properly, or not. That the
fluid look fresh would indicates to me it was not serviced properly and it
was run dirty then
changed by the seller before your purchase. You might try some STP, if that
does not work and the whine is bothersome, change the pump or turn up the
radio, WBMA ;)
I replaced the power steering pump on my Aerostar last summer. The
rebuilders instructions said the pump may whine for a short time after
replacement. Mine whined from day one.
I was too lazy to change the oil two weeks ago, so I took it to the local
oil change place, they vacuumed out the powr steering fluid and replaced the
fluid with new. Took care of the whine in my 93 Aerostar.
The guy said the slightest amount of water will contaminate the fluid and
cause a whine. He said this is common on Fords and vacuuming out the old
oil usually fixes the whine, worked with me.
I don't know if it would work for you or anyone else but, I
have had good luck putting 2 oz. of Lubegard Red in all 3 of
my current Fords. They all went silent after a couple of
days. I think the Lubegard may have a deareating additive
as I have seen the same results in the E4OD transmissions I
have used it in. There are probably other additive that
would work but, that iss the limit of my anecdotal
experience. As was pointed out, there is a vacuum pum
adapter that can aid in purging air from the system when
filling. If you ever get a quiet one, make damn sure it is
never low on fluid.
I may be wrong but, I believe the sound may be the pressure
control valve chattering which is aggravated by small air
bubblets in the fluid. That is why I believe Ford came up
with the vacuum adapter to use when filling the system.
Most hydraulic systems do have a noise problem similar to
this if there is any air entrained in the fluid. I think
the system probably runs too warm for moiture to remain a
problem in a closed system.
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