foamy power steering fluid

billshoff · Post by **billshoff** » 03 Jul 2010, 07:17

The power steering on my '01 V70 T5 (101k miles) groans when I turn the steering wheel sharply. We checked the fluid and it was foamy and under a lot of pressure. My independent Volvo repair shop thinks I need a new steering rack but I don't understand how he can accurately make that diagnosis just from foaming fluid? The steering isn't stiff and I don't see any fluid leaks. We're talking $1400 for a new rack and pinion install so I want to be sure he's right before I proceed. Any ideas?

I bought the car used in April so I don't have a history on it...accept the Carfax, of course.

Post by **JDS60R** » 03 Jul 2010, 09:11

If the level is correct ,foaming fluid is a sign of an air leak where the line attaches from the resivour to the pump ,the pump itself ,or anywhere a connection is made where the fluid flows by . In order for it to foam it must pull air in (fluid moving fast by a small air leak). The whole sysem can be checked for air leaks by pressure testing the system -much like a radiator.

If the level is not correct just top it up. Keep in mind the froth in the fluid now is displacing some of the area where fluid should be so filling the resivour while it is running to help purge the bubbles is a good idea.

Post by **FlyingVolvo** » 03 Jul 2010, 13:15

It's also possible someone topped up at one point with a conflicting fluid. Before doing anything drastic, I would get new fluid in there. Use a turkey baster to suck out as much as you can from the reservoir and then add however much you took out. Do this a few times, with some driving in between (lots of turning!). Then check it all again and see how the fluid looks.

If you mix fluids like ATF and the OEM Hydraulic fluid, you can get issues.

claymore850 · Post by **claymore850** » 03 Jul 2010, 17:59

You can start checking all the conections, look the return with rubber hoses....your system is sucking air in a conection..

Also you have the be sure the correct fluid is on the reservoir...on this model you CANT use the ATF...place only OEM steering fluid

Check all hoses...replace the fluid....start the car without the cap, move the steering side to side for a few minutes,to let the system be free of air..

skibo · Post by **skibo** » 08 Jul 2010, 20:43

I had the exact same problem a year ago on my '04.

Within the PS reservoir, there is a small tube that directs the return fluid to the bottom of the container. It just snaps into place, and my had come off, so that the stream of return fluid was hitting the surface of the fluid already there and churning it up.

I removed the reservoir, cleaned it inside and out, and snapped the tube back into place. After 14 months, no problem (knock wood).

billshoff · Post by **billshoff** » 09 Jul 2010, 06:32

Thanks for all the feedback. I checked my fluid yesterday after a short run around town and it wasn't foamy so I might not have driven long enough for it to get hot. I don't drive this car every day so I need some time to experiment with your ideas.

I guess the fluid needs to get hot before it will foam and most of my trips are short. I'll let you know what I find in the days ahead.

Retired MVS Contributor · Post by **Retired MVS Contributor** » 09 Jul 2010, 10:59

For several years the Volvo owner's manual was wrong and they eventually corrected it, in 2005, I think...It called for ATF for the power steering...I understand that foaming was one of the problems with ATF in these cars... The proper fluid is Pentosin CHF-11S and it is synthetic...The best price I have seen for Pentosin is GermanAutoParts at $19 and change per liter...After draining the reservoir and refilling, I would disconnect the upper (return to reservoir) hose and run the engine a short time, catching the fluid pumped out of the rack in a bottle...Then refill with Pentosin again...This won't completly purge all the ATF (you would have to also crank the rack lock-to-lock to do that) but it will get most of it...Of course you could crank it back and forth, but you would have to stop at each lock and refill before continuing...Watch the inside of the reservoir with a light and as soon as it is empty SHUT DOWN and refill...

osprey2 · Post by **osprey2** » 09 Jul 2010, 13:04

On my V70 I had the pump replaced and it didn't help. Finally I found this: in the fluid reservoir there's a spout which returns the fluid below the level of the fluid already there. The spout gets broken (no idea how). Fluid is aerated, gets frothy, bubbles over, rack groans. The fix: get a new plastic reservoir..just a few quid.

Ah: spotted the reply above which says what I've said. Too keen to be a smarty-pants. Cheers

Retired MVS Contributor · Post by **Retired MVS Contributor** » 09 Jul 2010, 14:45

If you use the turkey baster as a previous member suggested, you will be able to tell the color of the fluid...If it is red, it is ATF and is the wrong fluid...Pentosin is green...Foamy fluid has air bubbles mixed in and will make noise due to cavitation...The air does not get mixed into the fluid due to an air leak somewhere,it gets introduced right in the reservoir when the returning fluid agitates and swirls the reservoir, whipping it into a foam...Pentosin has additives to prevent that...

http://new.volvocars.com/ownersdocs/200 ... .htm#pg154

Switchblade · Post by **Switchblade** » 08 Sep 2010, 22:56

I got the same foaming when the fluid level was low (caused by a leaking rack) - although perhaps it was also caused by sucking in air??

I got quoted $700AU for a new rack installed by Pedders, so instead I put in a bottle of Lucas' Power Steering Stop Leak which surprisingly stopped the groaning and tight spots - I'm waiting to see if the leak stops now.

Benjamin