Power steering fluid is often considered one of the most neglected fluids on a vehicle. Most service schedules don't cover it, and most people only think about it when something fails. But power steering fluid gets quite hot and worked, so it should be changed on a scheduled interval. Also the power steering fluid is what gives us power brakes, so its a good idea to properly maintain it.
My truck just hit 60 months of service, and is at 49K miles. I was going to be under-hood for a coolant flush so decided to do my power steering fluid.
I started off with the service manual instructions.
Originally Posted by 2005 Service Manual
FLUSHING POWER STEERING SYSTEM
Flushing is required when the power steering/hydraulic booster system fluid has become contaminated. Contaminated
fluid in the steering/booster system can cause seal deterioration and affect steering gear/booster spool valve
1. Raise the front end of the vehicle off the ground until the wheels are free to turn.
2. Remove the return line from the pump.
NOTE: If vehicle is equipped with a hydraulic booster remove both return lines from the pump.
3. Plug the return line port/ports at the pump.
4. Position the return line/lines into a large container to catch the fluid.
5. While an assistant is filling the pump reservoir start the engine.
6. With the engine running at idle turn the wheel back and forth.
NOTE: Do not contact or hold the wheel against the steering stops.
7. Run a quart of fluid through the system then stop the engine and install the return line/lines.
8. Fill the system with fluid and perform Steering Pump Initial Operation, (Refer to 19 - STEERING/PUMP - STANDARD
9. Start the engine and run it for fifteen minutes then stop the engine.
19 - 64 PUMP DR/DH
10. Remove the return line/lines from the pump and plug the pump port/ports.
11. Pour fresh fluid into the reservoir and check the draining fluid for contamination. If the fluid is still contaminated,
then flush the system again.
12. Install the return line/lines and perform Steering Pump Initial Operation, (Refer to 19 - STEERING/PUMP -
This was a very straight foreword flush. To make it go easier the first thing I did was disconnect the cooler under the radiator and get all the fluid to drain from the system.
Then I pulled the driver side fender-well and removed the hose from the bottom of the reservoir. Pre-draining the return system made this a easy, mess-free process. Then to plug the return port on the reservoir I screwed a 1/4 NPT plug into it. It got about 2 easy turns and I stopped. There will only be static pressure, and it should hold just fine. To get the return line to dump into a bucket I pushed a piece of 1/4" fuel hose into the return line and used the OE clamp to clamp it there. Then the hose was easily bent and put into a bucket.
Then I filled the reservoir with clean ATF. (I chose Amsoil ATF, IMHO the best ATF one can buy). Then my wife helped me out a little. She turned the key on (engine off) and turned the wheel until i had fluid coming from the return line, so now I had full fluid agian. I once again ensured the reservoir was full (about .8QT if its completely empty). Now we started the truck per the instructions and turned the wheel. I held an empty qt bottle under the hose so I would know when to shut the truck off before it ran dry, worked great.
We did this one more time, even thou it only calls for it once.
Now I buttoned everything backup and followed the Initial start up procedures, omitting step 6.
Originally Posted by 2005 Service Manual
POWER STEERING PUMP - INITIAL OPERATION
WARNING: THE FLUID LEVEL SHOULD BE CHECKED WITH ENGINE OFF TO PREVENT INJURY FROM MOVING
CAUTION: MOPART ATF+4 is to be used in the power steering system. No other power steering or automatic
transmission fluid is to be used in the system. Damage may result to the power steering pump and
system if any other fluid is used, and do not overfill.
Wipe filler cap clean, then check the fluid level. The dipstick should indicate COLD when the fluid is at normal
1. Turn steering wheel all the way to the left
2. Fill reservoir up to FULL HOT level and crank engine until it just starts. (DO NOT TURN STEERING WHEEL)
Then turn vehicle off. And re check fluid level, to Full COLD.
3. Crank engine again until it just starts, (DO NOT MOVE STEERING WHEEL) and turn vehicle off. Recheck fluid
level to Full COLD.
4. Turn engine on again, (DO NOT MOVE STEERING WHEEL) and let the vehicle idle for 5 minutes. If possible
apply a 20 in-Hg vacuum to the reservoir, while engine is idling.
5. Turn engine off and recheck fluid level, to FULL COLD.
6. If the Steering gear is replaced. ensure reservoir is at FULL HOT level, start engine and turn wheel to left. Stop
Engine and recheck fluid level to FULL HOT. Start engine and turn wheel to the right. Stop engine and check
fluid level is at FULL COLD.
7. Fill the pump fluid reservoir to the proper level and let the fluid settle for at least two (2) minutes.
8. Start the engine. With the engine idling maintain the fluid level.
9. Raise the front wheels off the ground.
10. Slowly turn the steering wheel lock-to-lock 20 times with the engine off while checking the fluid level.
NOTE: For vehicles with long return lines or oil coolers turn wheel 40 times.
11. Lower the front wheels and let the engine idle for two minutes.
12. Turn the steering wheel in both direction and verify power assist and quiet operation of the pump.
If the fluid is extremely foamy or milky looking, allow the vehicle to stand a few minutes and repeat the procedure.
DR/DH PUMP 19 - 65
CAUTION: Do not run a vehicle with foamy fluid for an extended period. This may cause pump damage.
The only thing I think the procedure is missing is to pump the brakes while turning the wheels. I didn't do this and got groaning the first two times I pumped the brakes. I went for a test drive and had to add a bit more fluid again. I haven't driven enough to see if there is a difference, but I would hope there isn't, indicating I did the service early enough.
All in all I think I used about 3 qts of fluid, thou I would have a gallon handy.
I will do this service every 50K miles.