what does bubbly brown power steering fluid mean ?

msm15 · Post by **msm15** » 02 Feb 2009, 22:13

Recently I started hearing a constant noise coming from the power steering pump area and my steering started making noise on turns, so I opened up the power steering cap today and noticed it was almost empty and all that remained was a little bit of light brown fluid with lots of bubbles - almost the color of you coolant in the presence of a bad head gasket. I filled up the power steering reservoir with a lot of clean ATF fluid and it was totally taken over by the brown bubbly stuff - very quickly. After I added it I turned the wheel all the way to one side and then the other back and forth a couple of times (with the car running of course) to get the new fluid it. At first it didnt sound like it was helping, then after letting it sit and coming back later I could see a noticeable difference but it still is not where it should be.

I checked the power steering fluid about a month ago and it was not low at all but it was dark and in need of changing but I guess I forgot about it. Also there are no signs of any major power steering fluid leaks (I do have an oil leak but that is something else).

the noise coming from the power steering pump area sounded like a bad bearing - I say a bad bearing because thats what it sounded like but I have no idea if its true or not - it did however go away after the new fluid went through the system.

so here are my questions

1. whats up with the light brown bubbly fluid coloring - is this supposed to be an air tight system ? do I have an air leak ?

2. where could my fluid have gone ?

3. any clues on the bearing sounding noise ? once the problem came on it was audible whether I was making a turn or not.

4. should I do a complete drain and fill, if so how do I do that and what fluid should I use in the system ?

thanks for your help guys

Post by **MadeInJapan** » 02 Feb 2009, 22:22

I don't have all of your answers, but yes, I would flush it immediately. Here is a write-up I did some time ago that addresses how to do this: https://www.matthewsvolvosite.com/forums ... php?t=8644

msm15 · Post by **msm15** » 02 Feb 2009, 22:54

wow great, thanks for the reply MIJ but how do I get the air out of the system ?

Post by **MadeInJapan** » 03 Feb 2009, 06:25

The reason you have air now is because the fluid was low (not sure why without a leak, but that's next if the fluid disappears again). After filling up the reservoir, turn your wheels left to right several times and the air will work itself out. Drive it somewhere to test drive it where you have many turns, come back and check the level again. If there are no leaks and you've turned your steering left to right several times during your drive, the air should be out of your system. You might want to try a flush again in the near future. Make sure you use the right fluid- Dexron III...don't use something just labeled "power steering fluid," this can mess your system up on a Volvo.

dnfrick · Post by **dnfrick** » 16 Mar 2009, 20:01

I had this exact same problem. It is caused by old degraded ATF that Volvo uses for power steering fluid. When the fluid gets too old it starts to foam, leading to air bubbles being drawn into the pump. The pump does not like compressible fluid and makes a lot of crackling noise, like marbles rolling around. Drain the system and put fresh ATF in and your problem will disappear.

binglax09 · Post by **binglax09** » 17 Mar 2009, 18:24

Also, Ive found that a thicker ATF additive will help a lot out with older fluid if you can't do a complete flush right away. A thicker additive will help reduce the amount of bubbles that form in the PS system.

Also, hydrualic fluids have anti-form additives that with age diminish.

Ive got the same thing happening to my S60 T5M. If I let it sit over night the bubbles dissipate and it's good to go for most of the day. I'm also low on fluid... To lazy to do a flush haha. No harm in having bubbles..

msm15 · Post by **msm15** » 17 Mar 2009, 19:08

thanks for the input guys, but unfortunately I have a major leak out of the right side of the rack. If I let it sit for not even 2 minutes after I park - I get a nice 3 inch wide puddle - thats not an exaggeration. I already picked up a rebuilt rack and I'm hoping to do the fix this sunday