How to: Genpu Power Steering Fluid Flush

From my how to thread on the other forum...

Here's a quick how-to to replace nearly all of the power steering fluid on Gen2 MS3. I have always been surprised that manufacturers create service schedules to deal with major fluids on the car (oil, transmission and coolant) but neglect the smaller systems and treat them almost as an on-condition servicing of the fluid level only. At any rate after 75k miles and 5+ years on my Pu it was time to figure it out so I don't have to replace my PS pump unit at some point in the future.

After some research I found a video on Youtube of a guy doing the same service on a standard MZ3 so feel free to watch that as well. I will forewarn you he becomes a bit painful to listen to. Regardless, I can't take full credit as this guy did a decent job of documenting the process.



Let's get started.

Tools:

• Jack
• 2 jack stands
• lug wrench or impact
• torque wrench
• 10mm socket and ratchet
• 8mm socket or Phillips screw driver
• small bowl/Tupperware type container to catch fluid
• rags
• 1 Qt of the appropriate fresh PS fluid (I used Amsoil PSF)

Steps:

1. Get the front of the car up on jack stands
2. Remove the right front tire/wheel
3. Remove the fasteners and plastic plugs for the front half of the inner fender well including the section that attaches to the front bumper cover near the lower lip. (ref pic #1)
   
4. Place your catch container under the two PS fluid lines on the lower tray (ref pic #2 where the drop light is)
   
5. Disconnect the upper hose (low pressure return line) and let the fluid in the pump reservoir drain into the container. (ref pic #2)
6. Unlock the steering wheel and run the wheel back and forth lock to lock several times to work most of the fluid out of the rack and pressure line. (Do not do this with the engine running)
7. You'll know you've done it enough when you hear sucking sound going both directions and fluid stops coming out.
8. This is where I note that you're not going to get all the fluid out of the system but you should get most of it out. I didn't find a system capacity but I got approximately 20oz out.
9. Reattach the hose to the plastic return line and reseat the hose clamp.
10. Clean up any mess.
11. Reattach the inner fender covers
12. Reinstall the tire/wheel (Lug torque 70-90 ft/lbs)
13. Move topside and fill the reservoir with new fluid.
14. Turn the wheel back and forth lock to lock several times.
15. Repeat - fill & run the steering wheel back and forth. I think I did this four times.
16. Once the system is not taking anymore fluid doing this mechanically it's time to start the engine and run the wheel back and forth slowly.
17. Make certain you keep an eye on the fluid level as it will go down as you do this process a few times.
18. All told I serviced the system with ~20oz. of fluid before the level stopped dropping.
19. Reinsert the little screen filter, rubber seal and install the cap.
20. Take the car off jack stands.
21. Go for a drive.
22. Check fluid level after return.
23. Crack a beer and enjoy.
24. Make a note to do this again in 50-60k miles if you plan to keep the car.

If you're doing this by yourself it shouldn't take but 45 mins to an hour, less if you have two people.

Have a look at the crap in the fluid and difference in color from new fluid. I did notice a slight difference in the sound of the PS pump unit, it's probably happy to have fresh fluid versus the dirty shit. Take note the metal container was an acetone jug and had no crap in it before starting. It gives you a good idea of the particles in the system.

 

I haven't looked in the manual in a while. I was considering doing the coolant, but found that the conventional wisdom is I'm golden until 100k. Did you not find this to be the case for P/S too? It's interval should be listed... hmmmm.....

 

I have yet to come across any OEM that recommends changing or doing anything to PS fluid other than checking the level and topping it off. Even Merc has nothing in their service schedule and they cover fluids pretty well. I'm not applying any science to my notion, just my nickle of common sense that the fluid heats up, cools, repeats so it's likely there is moisture in the fluid and the additives break down over time. Synthetic PS fluid is cheap and takes little time swap out. I'll just coordinate the next scheduled flush to sync up with the nearest 6 month MX event to keep blocks if service easy to manage.

For what it's worth I did drop the Mazda coolant interval in my MX spreadsheet to 100k or 10yrs whichever occurs first like you mention, coolant too is cheap and its additive package breaks down over time. I have a hard time believing a coolant's additive package can effectively last that long without starting to negatively impact the metals and rubber bits in the engine.

 

I thought we used ATF for our power steering??

 

We do. I used synthetic in mine, figured I probably wouldn't need to change it again that way, at least until my sketchy pump gives out.

 

Ok.. I recently got a little maintenance bug up my ass at 70k. I did Brake fluid, Tranny fluid, dry compression check, and radiator flush and fill over the past couple weeks. I think im going to do this next, thanks for the write up/ reminder. Need to do valves too but meeeeth soon.

 

After 70k, methanol won't clean it out (not that you said it would). But having it installed before cleaning the valves will definitely keep them clean, especially if run in conjunction with a disabled/eliminated EGR and an OCC.

 

Thanks for the write up Redline. @106k on my genpu & most likely need to flush the system of the old fluid.

 

Question, a buddy of mine has a bunch of Honda power steering fluid and he gave me a few bottle when I told him I was low. Is it something I could use or is there something better recommended?

 

This works for gen 1 as well. I did a few times.
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Look up the specs of the Honda fluid and compare against dextron 4. Read multiple times the owner manual calls for dextron type ATF in the mazdaspeed.

 

I just use a mittyvac to suck PS fluid out the reservoir every oil change. Then top it off.

 

I have no idea, you'd have to look into whether it's comparable with what Mazda uses. Unfortunately, the Asian manufacturers don't use published spec numbers like the European manufacturers do.

 

Why not just buy a quart of ATF?

 

I picked up a case of Ford Mercon V, used it on our mustang and for the Pu steering flush.

Still strong a year later.