Does power steering fluid need changing?

Joined
Feb 4, 2020
Messages
99
Location
Schaumburg, IL
I notice that the maintenance schedule on 2011 Subaru outback said to inspect power steering fluid but it doesn't have a schedule to replace it like in items like brake fluid. Does power steering need replacing after a few years? Paul
 
Joined
Jan 3, 2009
Messages
15,022
Location
Illinois
Every engine oil change I turkey baster the PS pump and add M1 ATF. This has worked very well with no pump or rack failures in 30 years that M1 ATF has been on the market.
 
Joined
Apr 25, 2017
Messages
8,340
Location
Ohio
Don't you love automakers that say "Inspect fluid..." and nothing more ? Inspect it for what ? Do what if you find what ?
 

Paul_Siu

Thread starter
Joined
Feb 4, 2020
Messages
99
Location
Schaumburg, IL
I imagine you change it when it looks dirty. Brake fluid collect water overtime, so I change it every 2-3 years. Power Steering does not collect water? The turkey baster is an interesting idea, but if you use that method wouldn't you just replace the fluid just in the reserve tank. Wouldn't a drain be more through, tig1 seems to indicate that didn't matter for him.
 
Joined
Apr 25, 2017
Messages
8,340
Location
Ohio
My understand is that power steering fluid circulates so removing some dirty fluid and replacing it with clean fluid does work well. Brake fluid doesn't circulate, at least nowhere as much as other fluids. There's no inlet and outlet in a hydraulic brake system. The fluid is just pushed (compressed) back and forth. Regarding changing if it's dirty, define "dirty". That's entirely subjective.
 

Astro14

$100 Site Donor
Staff member
Joined
Oct 10, 2010
Messages
16,588
Location
Virginia Beach
Power steering fluid isn't as hygroscopic as brake fluid but it does get contaminated by pump and rack wear. Mercedes puts filters in their power steering systems to filter out those contaminants. Mercedes has a change interval, and I apply that to every vehicle. I've had several cars go over 200,000 miles on original steering components (pump and rack/box) which I attribute to filtration and fluid changes. I don't go crazy, but every 50,000-60,000 miles, I do a change. With a rack for my Volvo's costing over $1,200 (Part only, and friends don't let friends use Cardone rebuilds) and requiring subframe removal to change, I would rather change the fluid periodically and plumb in a filter.
 
Joined
Dec 31, 2017
Messages
12,449
Location
SE British Columbia, Canada
Originally Posted by Paul_Siu
I imagine you change it when it looks dirty. Brake fluid collect water overtime, so I change it every 2-3 years. Power Steering does not collect water? The turkey baster is an interesting idea, but if you use that method wouldn't you just replace the fluid just in the reserve tank. Wouldn't a drain be more through, tig1 seems to indicate that didn't matter for him.
Turkey basting is fine. The "Side-slip" theory of replacing fluid is not bad if you do it more times than replacing all the fluid by removing a hose. Remember that 100% will never be replaced using a turkey baster several times so if that causes you concern or you can't sleep at night then by all means go ahead and pull a return line, put it in a bucket and do a transfusion of the whole system. I have 200,000 miles on a Chevy power steering system including a hydro-boost using the Turkey Baster method once per year. smile
 
Last edited:
Joined
Sep 24, 2015
Messages
334
Location
Rainville, USA
Yep turkey baster with OEM fluid (and as noted earlier, in my Mercedes a filter/reservoir change) every so often keeps pumps parts happy and quiet, takes almost no effort, I've also never had to a line disconnect flush because of this routine maintenance
 
Joined
Sep 6, 2007
Messages
2,179
Location
TX, USA
Flushing the P/S fluid is very easy. Just search Youtube and you can watch a few movies with different tips that fit your particular car. The Toyota and GM are easy to do. Not sure of others because I have never own it. I helped somebody with a Ford made Mazda a while back and it was the same process. My former Sienna had a P/S fluid leaks when I bought it. The leak went away after I did a fluid flush. Not sure why but I was glad that the issue is fixed.
 
Last edited:

Paul_Siu

Thread starter
Joined
Feb 4, 2020
Messages
99
Location
Schaumburg, IL
OK, I took a look and found the power steering. The fluid appears to be a dark red and is probably ok. The problem is that the hole is really tiny so I have to find something more narrow than a turkey baster. Paul
 
Joined
Aug 28, 2017
Messages
3,309
Location
near Cincinnati, OH
You will get a little more life out of PS by changing it regularly, but unless you have a working crystal ball you'll have to make your best *guess* about whether you still end up having to replace the rack or pump and then it may have enough life till you retire or sell the vehicle, so the time changing it was wasted. That's the thing about crystal balls, they don't help to predict some texting teenager plowing into it and totaling it. Some factors are out of your hands no matter how hard you try to make something last forever. Replacement every few years is a good idea, but every year is excessive unless you're putting on a lot of miles in the twisties.
 
Last edited:
Joined
Sep 24, 2015
Messages
334
Location
Rainville, USA
Originally Posted by Paul_Siu
OK, I took a look and found the power steering. The fluid appears to be a dark red and is probably ok. The problem is that the hole is really tiny so I have to find something more narrow than a turkey baster. Paul
Try the battery water turkey baster type things all auto parts stores have, it's actually what i use, works better in the Mercedes
 
Joined
Jan 25, 2018
Messages
1,528
Location
South Carolina
I like to do a PS flush about every 2 or 3 years. It is probably not necessary, but neither is changing full syn oil every 5k. However, these things give me a warm fuzzy feeling and my steering is always smooth as butter; neither of these happen with old PS fluid.
 
Joined
Jan 9, 2010
Messages
13,541
Location
Los Gatos, CA
I have serviced numerous Honda/Acura PS systems and our old Tundra. Every time I am rewarded with that new car steering feel. I highly recommend it.
 
Joined
May 15, 2012
Messages
5,622
Location
The land of USA-made Subies!
In my Subarus I turkey baster out the old stuff and use MaxLife ATF for the new fill. I usually suck the reservoir as dry as I can, top it off, go for a short drive, and repeat 3 or 4 times before calling it a day. I usually do this every spring on each vehicle, when the "get out and do stuff" bug has hit and before the "OMG, it's time for maintenance AGAIN" bug hits in late fall.
 
Joined
Jan 29, 2012
Messages
681
Location
Canada
Add an inline filter if you absolutely insist on going extended intervals with the power steering system. I know the reservoir has a mesh, but being able to filter more efficiently down to smaller particle sizes is never a bad thing.
 
Joined
Aug 4, 2011
Messages
2,572
Originally Posted by SubieRubyRoo
In my Subarus I turkey baster out the old stuff and use MaxLife ATF for the new fill. I usually suck the reservoir as dry as I can, top it off, go for a short drive, and repeat 3 or 4 times before calling it a day. I usually do this every spring on each vehicle, when the "get out and do stuff" bug has hit and before the "OMG, it's time for maintenance AGAIN" bug hits in late fall.
Yep That's exactly what i did yesterday till I flushed out a quart
 
Last edited:
Top