Mechanics

POWER STEERING FLUID DISAPEARS

1999 Mercury Sable

Steering problem
1999 Mercury Sable 6 cyl Front Wheel Drive Automatic 85000 miles

Hello. As you see I am new to this forum. I registered in order to help a friend out who owns Ford Taurus. It is a 1999 model, but anyway, he has been having some trouble with his power steering. At first I thought the problem was linked directly to there being air in the line, but after the proper procedure was performed, it didn't help any. Okay though, here is the problem. The power steering pump will remain full with fluid as long as the engine is not running; however, as soon as the engine is cranked, the power steering fluid is sucked direct into the system and the power steering reservoir in emptied completely, but here is were it gets weird. With the engine running we would add powersteering fluid into the reservoir to fill it up, but immediately after he turned the engine off again, the powersteering fluid would begin to overflow out of the top of the reservoir.

It sound crazy, but I saw this with my own eyes. What could be causing this issue, first there is fluid in the reservoir, cut the engine on and then its sucked in, add fluid to fill the reservoir because of that, and then turn the engine off and watch as fluid begins to overflow out the reservoir.
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Hatchethero
March 21, 2008.



There is a restriction most likley.

There may be a problem with return hose assy. On these. You need to get a new one from the dealer.
You can test it by bypassing the old one with a line from the rack to the pump. There may be an in-line filter that is plugged.

Has the rack been replaced?

There is also a TSB on a particular bleed procedure on this that may have to be performed after you solve the restriction issue.

The rack has not been replaced. I took it to a shop and they said it was the pump, but when they replaced the pump the problem actually got worse.
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Tiny
Hatchethero
Mar 21, 2008.
I would expect a restriction then. The additional power from a new pump would be logical to make it worse. Try the bypass like I said or have a pressure gauge hooked up to it at different points until the pressure loss is found. It sounds like the pump is overcharging the system up to the bocked point (probagbly in the return line as that is the last point before it can reach the pump since it isn't returning the reservior it keeps sucking more fluid to over capacity. Addittional Hot fluid will expand and more pressure will heat it up as well. You shut it down and the fluid wants to decrease pressure spitting it back out the reservior.


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