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Power Steering Flush Reminder

new 3/5/03, updated 02/06/2005

V8SHO had a letter this week, a high mile V8SHO had a numb spot, 1/2" of slack in the steering.  Not fun for anyone use to the precise touch of the SHO.  This is just a reminder. The V8 SHO has a ZF Rack & Pinion and power steering pump. Ford DOES NOT have a PM interval for this fluid. We know from oil analysis that by 50k the PS fluid is totally worn out. If you don't have to replace the whole steering system you will at best have a sloppy numb unresponsive system. May I suggest a 20k-30K flush interval is far more prudent.

Cost to flush the PS system is less than $10 fluid and maybe another $10 labor. Cost to replace the ZF system is almost as much as a engine, $3,000-$4,000. 

Pays your monies, make your choices.



Ok! The front valance? Before I go on my guess - what is it? It's the
grate/grill under the wiper mounting shaft - correct?

I'm going to try a 100% fluid exchange.

Pete -
No. And No.
The Front Valance is the Large Black Plastic piece UNDER the radiator
which also mounts the lower front airdam. It is held in place by 3 -
8mm bolts and 4 million little 5.5mm bolts. There may be a phillips
head or two around the wheelwells too.
You DON'T want to do a full drain/Fluid change. You will get air in
the system in places that it is hard to purge. Best bet is a Paul Nimz
trick. Take a turkey baster and suck out all the fluid from the P/S
reservior that you can. Top of with new fluid and drive for a day or
two. Drain as much as you can again and repeat the process. Do this
several times until your fluid is nice and clean.
Repeat - It is NOT recommended to do a full drain on the power steering.

Eric Lehmann

I had mine purged and refilled at Merchants a while ago, they hook it up to
a vacuum device and do the whole process, bleed the system out completely. I
think it cost $69. Since then I have discovered that almost no one does this
around here.

For the interim I tried this using one of the cheap fluid pumps they sell at
Advance, what a waste of $7.99 that was. Didn't pump for s*** and now I
can't use it for anything else. So I dug out an old turkey baster and it
worked like a charm. After a couple rounds of pumping and topping off my
fluid was noticeably cleaner and didn't smell burnt anymore, helped a lot.
W. Gordon Finley
97 ES
Yep! Did mine that way. When I had put 4 quarts total of new in, I figured I
was done!
Paul L Fisher

Thinking out loud here wouldn't any of the gunk (scientific term)
migrate toward the lowest part of the system, and therefore be a
benefit to at least burping the drain?


When I installed the Magnefine filter on the PS line, I had to cut the
tube at it's lowest point. This allowed about a quart of PS fluid to
dump out (I essentially drained the whole reservoir and the big line
leading down from the pump toward the rack.) I was a little worried
about having to bleed the air out so it wouldn't collect in the rack,
but when I filled the reservoir with fresh fluid and started the car,
everything seemed fine. That was at about 55K miles (20K miles ago)
and there wasn't any appreciable amount of gunk in there. In fact the
fluid still looked pretty good. I haven't had any problems from it,
so I don't think any air made it's way to the rack.

Several times I have drained the system completely. Tires off the ground,
engine off, turn the wheel from stop to stop to empty the rack. Trip the
inertia switch and crank the engine to empty the pump and as much of the
fluid as possible. I have not had any problem with air in the system.

The trick is to fill the reservoir and crank the engine to fill the pump
and rack. You don't have to crank very long. When the system is almost
full, with the wheels still in the air, start the engine and slowly turn
the wheel from stop to stop. Do not hold the wheel against the stop. About
10 times should do. Lower the car and top off the reservoir.

IMO, all you're doing by emptying and refilling the reservoir is making
clean oil dirty. Sorta like changing the oil filter every other oil change.

Glen Murdock

The method you use, is what Doug Lewis does at FPS. Even if
there is a little air left in the system, just check the
level for the next few days, and top it off.

when he did my car, the level didn't drop more than a 1/4"
after the drive home.

I agree, just taking a little out at a time may put cleaner
oil in the system, but I feel that draining from the lowest
point will get more of the dirt, and get it all at once.

Be sure to flush some cheap new fluid through while still
draining. Then fill with Synthetic ATF for best performance.

Don Mallinson
I've done a complete (as near as possible without disconnecting the lines
at the rack)draining three times with no apparent adverse effects. With
front wheels off the ground and the PS hose removed at the cooler, I cycle
the steering lock to lock several times while cranking the engine
(starting disabled). I then pull the PS reservoir out and wash off the
screen with flow going out the return line connection. I have yet to not
find these screens coated with wear/decomposition material. After
reinstalling and connecting hoses, I fill the reservoir and crank the
engine. I top off the reservoir and cycle the steering a couple times
while cranking the engine. With the wheels back on the ground, I fire the
engine and let idle a few minutes. I then bump the wheels back and forth
sightly a couple times increase the steering wheel rotation each direction
until going lock to lock.
Lucien Frederick

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