Power Steering Fluid Flush?

[darajman]

Hi Everyone.

On my previous cars I used to do a complete drain and fill of power steering fluid once every couple of years.

My NC has some really manky looking PS fluid. It's a muddy purple/brown colour when fresh ATF is supposed to be clear red.

All the info I find on the internet and even speaking to a Mazda dealer mechanic, I'm being told that it's a completely sealed system and isn't meant to have its fluid changed.

But how about this bolt on the rack near the pinion gear (pictured)?
https://photos.app.goo.gl/beJKG3HDQbGmEaaH6

Would loosening or undoing this bolt allow me to drain the fluid in the rack?

Would undoing this bolt get me in any kind of trouble?

Thanks in advance for your replies.

[HarryB]

I like to replace PS fluid as well. However, DON'T mess around with the bolt you mentioned. This should set mechanical rack preload and thus backlash, and can be a pain to set correctly again. I would suck the fluid out of the reservoir and add fresh one; if you do that a couple of times, it should suffice to replace a very large percentage of the total volume with fresh ATF. Alternatively, remove the return (low pressure) hose of the system where it meets the reservoir.

[kung fu jesus]

PS fluid runs hotter than you might expect. Like ATF, is will start to brown as it's heated.

Harry is 100%. If your really want to get all the fluid out, you would need to remove the hoses at the rack and cycle the ram through it's range both ways. Also, you may want to research if there is a filter in the PS reservoir. A lot of cars have a fine screen filter in there and you either have to remove the reservoir to flush it or just replace it (the reservoir). That would be a little overkill, but the option is there if that is how this system works.

If you do cycle the ram with the lines off, it could get very messy. I think Harry's suggestion of getting as much out as you can through the reservoir, refill, cycle, repeat should get you farther ahead than 99.8% of owner do to this system.

[atlex]

aye... "If you do cycle the ram with the lines off, it could get very messy. I think Harry's suggestion of getting as much out as you can through the reservoir, refill, cycle, repeat should get you farther ahead than 99.8% of owner do to this system." yup that PS fluid will come out like a supersoaker if the hose is disconnected and not routed somewhere sensible :D ask me how I know!

PS fluid is cheap and flushing it by just emptying the reservoir and refilling it is honestly fine.. That or join up the return line to an extra length of hose (transparent is best) to route it to an empty oil bottle or something like that.