Power steering fluid flush problem

t5ftw · Post by **t5ftw** » 28 Jan 2011, 17:27

I have 99 S70 T5. I had left over ATF. So, I tried flushing power steering fluid. I siphon out the reservoir and refilled. turned on the engine, turn the wheel from lock to lock a couple of times, and turned off the engine. Then, repeated the process 4-5 times. My manual says to use ATF for steering fluid. But when I looked at the fluid, it was brown like a old engine oil. After the flush, I can barely move the wheel. What did I do wrong? Is there a chance that I damage anything?

Post by **Jack Rock** » 28 Jan 2011, 18:57

That brown oil used to be red, it's just that old and due for a change. I doubt you've damaged anything but it sounds like you have an air lock. Let the car idle for a while with the cap off, periodically and slowly turn the wheel lock to lock. If it's making a grinding noise you'll see tiny air bubbles coming up through the oil, otherwise known as cavitation. Take your time, I had the same thing happen to me.

Post by **confused_al** » 28 Jan 2011, 19:19

If your PS was using PS fluid previously, you dont want mix w/ ATF. As I recalled Volvo switched to use PS fluid somewhere in 1999/2000 model year due to different PS pumps were used (ZF pumps). Is your reservoir sits by itself or on top of PS pump? If yours is sits by itself, most likely you have a ZF pump.

Post by **confused_al** » 28 Jan 2011, 20:03

I found pics for these two different pumps.
the one with reservoir on top:

: ps pump 98.JPG (29.26 KiB) Viewed 3930 times

separate reservoir:

: ps pump 2000.jpg (321 KiB) Viewed 3931 times

Post by **Ozark Lee** » 28 Jan 2011, 21:07

To confused_al's point. I inadvertently mixed power steering fluid and ATF in my wifes old Jeep and it turned into a frothy gelatinous goo. I never did drive it that way but 4 or 5 iterations of the drain the reservoir, refill, run the steering lock to lock a few times and repeat cleared the system and it worked fine.

My Volvo's all take "a quality ATF" - per the owners manual - but I have nothing newer than a '98. In reality I think either one is likely fine but don't mix them together.

...Lee

t5ftw · Post by **t5ftw** » 28 Jan 2011, 21:23

My fluid reservoir does not look like those in pictures. Rather, I have something look like the one in the next picture. Does that mean ATF is still correct fluid but somehow previous owner used wrong fluid? I will probably let it idle for a while and if it gets worse, I will try flush more fluid out. Or maybe I should just flush with PS fluid? I will 'Never touch something that is working fine.

Post by **jblackburn** » 28 Jan 2011, 23:18

A '99 uses synthetic PS fluid not ATF.

You may have to remove the hose to the pump to flush out all the old junk out of there.

https://www.matthewsvolvosite.com/forums ... php?t=8644

t5ftw · Post by **t5ftw** » 29 Jan 2011, 09:15

I guess I made it really a bigger job.
I checked out local auto part stores like auto zone, advanced auto, O'riely, but none had any synthetic PS fluid. I see eeuroparts has it. Are the synthetic and non-synthetic fluids very different? Will it be ok to use non-synthetic temporarily?

Post by **jblackburn** » 29 Jan 2011, 09:24

If the VW dealer in town is open today, stop by and pick up 1-2 qts of the Pentosin power steering fluid.

Regular fluid would probably be better for it than ATF to get the flushing started anyway. I'm not sure how much the entire system holds.

t5ftw · Post by **t5ftw** » 29 Jan 2011, 09:44

Good idea. They open until 2:00 pm, but in Roanoke.