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Power Steering Fluid Change

Thanks to Sheriff Buford T. Justice:

Note: V6 SHO's are know to have issues with power steering pumps if the fluid is not changed. FOMOCO does NOT list changing the power steering fluid as part of normal PM but normal use will over time change power steering fluid to tar and pump replacement is very expensive.  After 50,000 miles my PS fluid tested 60W when it should be 20W, and was 36.7% oxidized.  Burned up Power Steering fluid has carbon crystals which is abrasive.  In my case I simply sucked out the old PS fluid and toped of the reservoir with fresh ATF fluid. If done every 10,000 -20,000 miles this should be sufficient.  - Timothy Wright (AKA "Buford")


Below Richard Mestier recommends a more through and professional procedure:


On the basis of Buford's PS oil analysis I decided to save $700 (cost of new PS pump) and flush the PS with Mobil 1 ATF immediately. My impression is that it's worthwhile and I recommend it to list members.

Steering used to be stiff on cold morning startup and then "mush up" as the fluid heated. Now it's consistent at all operating temps. Steering feel is noticeably improved, in particular at hwy speeds, because the viscosity does not plummet upon warm-up. Even a subtle steering wheel vibe at 75 MPH went away (thought it was tire balance, pleasant surprise). Operating noise is a smidgen quieter too.

I'll add my 0.02 to the instructions (culled from this list), below.

Point #1: To crank without starting, remove the top row, 5th from the left big fuse from the power dist box under-hood

Point #2. You might as well remove the PS reservoir from the firewall for ease of draining and hose removal. This will simplify return line hose removal (the smaller one). Throw a few rags down there before removing hose to save your driveway. You need 11mm and 8mm-(?pls verify) wrenches. Then you can drain the reservoir into a cut-in-half 1L coke bottle (you'll get about 375ml and it'll be BLACK !). Before your AWA cranks and turns the wheel as per instructions below, move the return hose forward and place into empty 2L pop bottle crammed between engine and rad - that way you'll be able to gauge the amount of fluid you've flushed. When you get 2L less the 375ml, you're done - cap the bottle and drop off for disposal.

Good luck and enjoy,
'98 ES
K&N Panel
Mobil 1 lubes


System Flushing

Always flush power rack and pinion steering gear when replacing power steering pump (3A674) due to fluid contamination.

1. Disconnect oil cooler-to-reservoir hose at power steering pump reservoir (3E764) and place end in a container. Plug nipple on power steering pump reservoir.

2. Fill power steering pump reservoir with Motorcraft MERCON Multi-Purpose (ATF) Transmission Fluid XT-2-QDX or equivalent meeting Ford MERCON specification.

3. Disable ignition and raise front wheels off floor.

4. While an assistant adds approximately 1.9 liters (0.5 gal) of Motorcraft MERCON Multi-Purpose (ATF) Transmission Fluid XT-2-QDX or equivalent meeting Ford MERCON specification, turn ignition switch to START position (using the ignition key) and crank engine with starter while turning steering wheel from lock-to-lock.

5. When all fluid has been added, turn ignition switch to OFF position.

6. Remove plug from the nipple on power steering pump reservoir. Attach return hose to nipple. Reposition hose clamp.

7. CAUTION: Do not overfill power steering pump reservoir.

Check fluid level. Add fluid if necessary.

8. Crank engine and recheck fluid level. Add fluid as necessary.

9. Lower vehicle. Enable ignition.

10. Start engine and turn steering wheel slowly from lock-to-lock several times. Check fluid level and adjust as required.


I'll give you a simple way to do it. Simple for me anyway. This procedure will work on any SHO.

Raise the front wheels off the ground. Support the car on jack stands. Disconnect the P/S cooler outlet hose. On a Gen3 this is the hose on the driver's side on the lower finned cooler in front of the A/C condenser. To access this hose you must remove the radiator splash shield, behind the bumper and under the radiator. 3 8mm bolts and a bunch of 7/32"? bolts. Place a drain pan under the cooler outlet. Gravity will drain the P/S reservoir. Turn the key to off. The notch before run. This will unlock the steering wheel. DO NOT start the engine. Make sure that the hose you disconnected is draining into the drain pan. Turn the wheel all the way left, then all the way right. Repeat this several times. This will pump the old fluid out of the steering rack. Reconnect the cooler hose. Fill the P/S reservoir with the ATF of your choice. Mercon is required, synthetics are optional. The wheels must be off the ground for this next step. Start the engine, slowly turn the wheel full left, then full right. DO NOT hold it against the stops. Repeat this several times. This will purge the air from the system. Check the reservoir level and top off if needed. Put everything back together. Lower the car to the ground. This procedure will change 60% (1 1/2 pints) of the fluid. It doesn't drain the pump, so you don't have to worry about running the pump dry. If you want to change more, just repeat the procedure after running the engine for a few minutes to mix the old and new fluid. IMO, if you do this every time you change the transmission fluid or, even better, when you change your antifreeze, you'll keep the fluid fresh enough.

Glen Murdock
Port Lavaca, TX
97 Pacific Green
89 Currant Red

The line going coming from the passenger side of the finned bottom cooler. As I just looked at it the line appears to be close to a 1/2" at the cooler but narrows down to 3/8" at the reservoir. Disconnect it at the cooler, plug the line going to the reservoir with a 1/2" bolt or something attach a 1/2" hose to the cooler and place in a bucket. I did it by using a gallon of cheap fluid, allowing all of it and about 1 & 1/2 quarts of the good stuff to flush out into the bucket. Then reattached all the hoses and top things off. I did all of this while someone else was cranking the engine with the ignition disabled.

Paul Nimz
'97 TR
'93 EG mtx

The Ford dealer already uses the BG Transmission Flush equipment and needed a test car to evaluate their Power steering flush equipment. Out of character, I offered my '97 at 45,000 miles as their test unit. They let me watch along with the service supervisor and two of the dealer's service guys.

First the fluid is pumped out of the power steering res. and the power steering cleaner is pumped in. The car is started and the wheels are turned lock to lock 10 times.

Then the cleaner is pumped out and the fresh power steering fluid transmission fluid is added to the res. and checked for proper level.

That was really pretty much it. The mechanics didn't say a whole lot just that they wanted the machine.

I, however, asked some questions based on the procures on this site.

1) Shouldn't the car be up on the rack when turning the wheels side to side?
No, you're just making the pump work and that helps clean out the power steering system.

2) Are there times when you need more than 10 turns to clean the system?
If the system is older or filthy then turn it a few more turns or drive it around the block to give it a deeper cleaning then flush it out.

3) Why is this now a problem? I have never had any power steering problems with any of my past cars.
When Ford went to plastic vanes in the PS pump they had to replace many steering rack at 30,000 miles. The contaminates, heat and metal shavings added even more waste material into the steering system. Also note that the PS res. that was mounted right on top of the pump is now located away to reduce the effects of heat on the fluid.

I wish some of you SHO owners could have been there to ask more in depth questions.

I would also add that the total time for this procedure on my car was around 10-15 minutes. The old fluid had a slight reddish color to it but everybody agreed that it wasn't bad looking at all- some had seen fluid that much darker.

I don't know what dealer will charge for this service but I some quick oil change place nearby asking $39.00.

The small machine (about the size of a battery charger) didn't look very expensive but who knows what the list price is.

In reviewing the change procedure for the do-it-your-selfers, should any kind of cleaner added to the system before the turning of the wheels and wonder if there are products that would help or is just a waste of money?

If you have experience with BG system (or another brand) please comment.

That's all from your SHO reporter in Central Indiana.

(Thanks to John Schmalstig for this contribution.)


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