How to change Power Steering Fluid

[RavenTai]

By request I have combined & condensed several posts by myself and others into this one.

Why change it? Power steering fluid is usually an ignored fluid, but over time and especially if overheated it can break down, oxidize, change viscosity, consume its additives, be contaminated with solids such as grit from the environment and wear metals from the pump and box, having no filtration these contaminants circulate endlessly causing more wear.

It is a good idea to occasionally change out the fluid to get rid of old fluid and the contaminants it carries. Although color is not the best indicator of fluid condition it is the easiest to check, if your fluid is looks considerably darker than new you should consider changing it to be safe. It is also a good thing to baseline this fluid after purchasing a 100K+ mile used 80 series as it has likely never been done before.

The classic method of changing PSF is to disconnect the return line, start the engine and turn the wheels lock to lock wile someone attempts to keep the reservoir full. The pump pushes the old fluid out the return line, wile this does work it is messy and almost impossible to keep up with the pump, an uncontrolled hectic and possibly pump damaging process,

I prefer a more leisurely controlled method

Supplies:
3 or 4 quarts of fluid
3/8" double barb
6' or longer of 3/8" tubing, clear vinyl “fish tank” tubing makes it easier to see what is going on.
3/8” hose clamps, these may not be needed if everything fits tightly, the pressure during this process will be low.
Cap for return port, I had a plastic shipping cap from a master cylinder that fit. You can also make one using a short section of hose and a bolt with a 3/8” shank. Or use a foam ear plug or just put a length of tube and lift the end above the reservoir.

Procedure:
1. Set parking brake.
2. Lock CDL so that park “gear” is still effective with only one axle on the ground. (put in low or set CDL switch with key on, then turn key off)
3. Block rear tires.
4. Lift front axle so the tires clear the ground,
5. Set the axle on jack stands being careful they will not interfere with the travel of the tires when turning, removing the front tires may be needed for clearance depending on your stands.
6. Enjoy the cold beverage of your choice.
7. Remove return line from the reservoir, it is the upper and smaller of the two hoses on the reservoir, it is a slip fit with a clamp. It comes in mid height on the side to an “L” shaped metal tube.
8. Catch the ~1/2 quart of fluid that drains from the return tube in the reservoir, Alternately you can take fluid out of the reservoir before hand so there is much less mess. plug the opening so the reservoir can hold fluid again.
9. Slide the barb into the return line you disconnected, slide the clear tubing on the other end of the barb, clamp joints as needed. Route the tube into a container or drain pan.
10. Fill reservoir with new fluid
11. Turn the key to acc to unlock the steering wheel but do not start engine, also do not leave in the "on" position for any length of time.
12. Slowly turn the steering wheel lock to lock.

As the wheel turns a large piston in the steering box will draw fluid from the reservoir through the pump, into the box, out to the cooler and out the return line to your drain pan, valves in the box keeps the fluid going in the same direction no matter witch way the piston is moving.

Keep the reservoir from emptying if air gets in it breaks the prime and it will take a bit to get going again, this will also form foam witch may lengthen the process.

13. When clean looking fluid starts coming out of the line reconnect the return line the reservoir, cycle lock to lock until the fluid level in the reservoir does not drop, you can get all/most of the air out by cycling the wheel lock to lock with the engine off, let it settle for a few minutes between cycling or the tiny bubbles/foam if present will just get reintroduced, repeat until air bubbles are cleared out

14. Start engine cycle lock to lock, check for leaks.

15. Return to your 80 to normal condition and wipe up any spilled fluid under the hood.

This was specifically written for 93-97 FZJ80s, but I think the system on the 91-92 FJ80s is close enough that these instructions will work.

I prefer this engine off method to the engine on method as with the engine running things happen very fast and it is almost impossible to keep the pump fed. Although running the pump dry for a short period is not likely to kill it, it is still counter productive IMHO.

Another simpler method is to remove the fluid from the reservoir with a turkey baster and fill the reservoir with new fluid, you are only getting a portion of the total fluid in the system This way so it will take many of these drain and fills (with driving in-between) to get the majority of the fluid replaced. Also the new fluid is mixed with the old each time so you will eventually run into diminishing returns. This is the method I use on my transmission, from time to time I drain the transmission pan and fill with new fluid, and this keeps the fluid in good overall condition.

Several have tried Mobil 1 ATF in the power steering system, many report they have groaning afterward, it may not be a good match for this application.


I had Originally used chevron fluid Dextron III and I do not remember any noise, about a year ago I did it again with some left over Transynd (A group III Castrol/Allison Dex III compatible fluid) and I do get light groaning when cold.

Downey has been reported to quiet Groaning by putting a teaspoon or two in the system.
I have yet to try it for myself.

More reading
http://forum.ih8mud.com/80-series-tech/30395-ps-fluid-flushed.html
http://forum.ih8mud.com/80-series-tech/77585-power-steering-flush-after-noise.html

I think this is going into the FAQ, if you have anything to add or correct please post up.

[Hayes]

Sweet.

For the FAQ's?

[RavenTai]

yes for the FAQ, I think it is going to go with the other fluid baseline FAQ's.

[Romer]

Excellent Job, thanks for the contribution, now to add this to the FAQ

[cary]

Just an FYI. I don't have any groaning with the Redline ATF, there is a just a bit of whine which was there before the fluid change. The pump has actually quieted down a bit since changing to the Redline ATF.

[RavenTai]

Originally Posted by cary

Just an FYI. I don't have any groaning with the Redline ATF, there is a just a bit of whine which was there before the fluid change. The pump has actually quieted down a bit since changing to the Redline ATF.

I reread your post and see what you mean, fixed above.


txkndu, I prefer the change out all at once for the PS but the over time method should still do OK.

[otis22]

changed out with Redline which minimized groaning, but Downey eliminated it

[e9999]

the thing that bothers me about the baster method is that you only get the top fluid, which is probably the cleanest. Any crud is probably settled someplace down below and would be left undisturbed this way...?

[Tools R Us]

Originally Posted by e9999

the thing that bothers me about the baster method is that you only get the top fluid, which is probably the cleanest. Any crud is probably settled someplace down below and would be left undisturbed this way...?

Take the cap off with the motor running and you will see that the fluid moves a bit!

[Tapage]

I do it myself few weeks ago ( 2 weeks ) more rudimentary with a lots of steering fluid around me and my engine bay ..

[e9999]

Originally Posted by Tools R Us

Take the cap off with the motor running and you will see that the fluid moves a bit!

thanks I'll pass, but yes, it would be better to use the baster immediately after stirring things up. Still not as good as the pumping method, though, I imagine.

[landtank]

Nice write up RT, I would have liked to have read this before my flush

[thomasando]

Thanks for the write-up. Really helped me the other day. Nice clean fluid now. The pump groaned before flushing, and still groans (no more, no less). I added some stop leak, and the leak I had has disappeared.

I don't think the overall condition of the power steering pump is real great in my truck...

[DTAYLOR]

Very nice Rav.

Got any ideas on flushing out a reservoir only off-vehicle?

[alaskacruiser]

Nice writeup, RT! Just another datapoint on M1: I recently flushed out my PS system with Mobil 1 ATF (had Valvoline semi-syn PS fluid in there before). I had no groaning problems before the flush, and I have no groaning problems after. Haven't added any Downey, either.

[DanKunz]

I think e9999 makes a good point on the baster method...best to do this once you run the truck and go lock to lock a few times to stir it up a bit.

Then suck it out, replace, etc with the engine off. Seems like you might catch more sediment/gunk this way.

[Romer]

I did this via an alternate method:

http://forum.ih8mud.com/80-series-tech/97993-new-way-flush-power-steering-fluid.html

[Rookie2]

Originally Posted by RavenTai

if you have anything to add or correctet please post up.

Hmmm..., Nothing I can see . Nice work as always RT.

[CreeperSleeper]

I agree. This was extreamly well written. Thanks

[RavenTai]

Originally Posted by Rookie2

Hmmm..., Nothing I can see . Nice work as always RT.

LOL, that is a good one,

I am glad you guys like it, having done this several ways over the years I really like this method but I'll go spell check some more.

[BOUNDER]

Originally Posted by e9999

thanks I'll pass, but yes, it would be better to use the baster immediately after stirring things up. Still not as good as the pumping method, though, I imagine.

And the pumping method still not as good as installing a brand new PS unit, I imagine

[Fly Rod]

Thanks for the write up on this PM.

I just changed mine, 124k, due to loud whining. It was bad enough that I could feel the vibrations through the steering wheel.

I followed your proceedures with a slight modification. I found that even with the engine off turning lock to lock emptied the resevoir very fast. I whent lock to lock once each way and it emptied the res. Once I started to add new fluid I realized that a siphon had set up. So I just kept adding fluid until it flowed clean. Not as fast as turning and filling at the same time but it worked and I didn't need help.

I filled with Mobil 1 Synthetic ATF and all noise and vibrations have dissapeared. This is a good simple job. It took less than 45 min. not counting the trip to the store for parts.

1/2

[KurtKuhn]

RT-

Thanks for the write up. This method worked well. I used this process after I changed out the larger non-pressure hose (the previous owner had a section of heater hose in there...ugh, I replaced with OEM).

Feedback for your method - Step 8: The 3/8 ID hose (clear fish bowl type) blocked off w/ 3/8" dia. bolt...I just could not get that to fit over the metal "L" return line. I wound up using a small~ish 1/2" ID hose that fit much easier over the flare at the bottom of the "L"; a hose clamp cinched up a good seal.

Thanks again for the write up.

-KK

[tomatopants]

I used a big syringe and some hose and stuck into the pump, and sucked some out until I couldn't suck anymore, put more in, turned the wheel a bunch and then repeated the process. It's not as through, but my power steering fluid is the color it's supposed to be now. IE, not black.

[RavenTai]

Glad you like it, it does work well,

one correction through, turns out there is some form of filtration in this system, I am not sure how fine or how effective ti is though,

Pics thanks to Photoman here:
http://forum.ih8mud.com/80-series-tech/188835-power-steering-reservoir.html


I think his idea of trying to get the funk out of the bottom sounds good.

[jmvar]

This was great, just did it tonight. It was really a lot easier and cleaner to suck out the old fluid in the reservoir before the return line is unplugged.

Plug the return line nipple on the reservoir with whatever plug you decide to use and then fill up with new fluid. Then proceed with the rest of the procedure to flush the system.

I probably spilled about 2 cap fulls of fluid....very little.

Thanks for the great info.

[mudking82]

Worked great for me too. Although I couldn't suck out much from the reservoir as there was some white plate like thing inside it. So I lost quite a bit when I pulled the return line. Also if you use the 3/8 hose barb, you might not want to push it all the way on the return hose. I did, and it was a MAJOR pain to get back off, especially since the hose was covered in fluid and really slick.