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06 Outback 2.5i
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Discussion Starter #1
Let me first start off by saying, my area does not get very cold. Southern california, maybe 45F in the winter. In the spring and summer, 55F is about the lowest it goes.

However, anytime it's below 60 in the morning, my pump whines quite a bunch, especially during the initial turn as I leave my driveway.

Back in December, I replaced the o-ring on the top of the pump (34439FG000). I mucked it up somehow, and as I backed the car out, ATF spewed out of the reservoir and anytime I turned the wheel, the car stalled. Since I was blocking the driveway, I had to pull it forward, and I ended up stalling it a few times by turning the wheel too much.

I replaced the o-ring correctly, bleed the system with the wheels in the air, and the reservoir level stays pretty steady, until the steering wheel nears full lock. The level will raise slightly until the steering wheel is backed off full lock. Is that normal?

I inspected the pump/hoses/reservoir for leaks last night - I couldn't spot any, everything was dry.

What's the next thing to try?
 

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2008 Outback Wagon LL Bean Limited 2.5i
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Is the seam between the “halves” of the p/s pump wet? If there a puddle of fluid on top of the engine behind the pump? It could be the seals in the pump are shot.


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2005 Outback R LL Bean 3.0 H6 w/ 5 speed sport shift
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Here's where I'd look for the problem:

First, when you had the leak, after installing the new O ring, along with spewing out the fluid, it also sucked in a bunch of air. My recommendation is that you jack up the front wheels off the ground, top off the reservoir and with the engine off, turn the wheels lock to lock a bunch of times - slowly! After doing this about 10 times or more, start the car only for a few seconds and shut back down. Then, go back through the lock to lock procedure. If you have someone to help, have them watch for bubbles coming into the reservoir.
This takes a while but it works. Do this before you drive the car. Like first thing of a morning - just not right after you've pulled into the driveway. Microbubbles form because the air is pressurized and it takes a while to work those out of the system.

The other thing to check is where the suction hose connects to the pump. They have a tendency to get dry and brittle over time and that contributes to suction leaks which leads to air in the system.
 

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2005 Outback H6 3.0 LL Bean
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1,204 Posts
All of the advice above is good, and definitely worth trying--you may have a suction leak that's only noticeable when the fluid is cold and viscosity goes up. If the standard fixes don't work, though, that doesn't necessarily mean you've done anything wrong or that the pump is bad. My pump has whined for years, ever since I got the car. It's the loudest thing on the engine, especially in the cold. I guarantee the suction side is 100% sealed, and I have also torn down the pump and rebuilt it with new o-rings and shaft seal. It works fine, but it's just a whiner.
 

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06 Outback 2.5i
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405 Posts
Discussion Starter #6
Lots of great advice here.

Which hose is the suction hose? Is it the one that goes from the reservoir to the top of the pump?
 

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06 Outback 2.5i
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Discussion Starter #8
Is the seam between the “halves” of the p/s pump wet? If there a puddle of fluid on top of the engine behind the pump? It could be the seals in the pump are shot.

Sent from my iPhone using Tapatalk
Pump halves are dry and no puddle on top of the engine behind the pump. Phew!

some models had a recall or TSB for bad pressure relief valves, I forget the specifics. maybe check recall list over at Subaru Research Site- specs, prices, options, 2018, 2017, 2016, 2015, 2014, 2013.... Outback, Legacy, Forester, XV Crosstrek, WRX, STI, Impreza, BRZ, Tribeca ?
Good looking out! However, the only TSB I could find is TSB 04-13-09R, which is for the pressure relief valves, but it only applies to Outback/Legacy H6 models. The symptom is listed as "If you encounter a vehicle that has a groaning type noise coming from the power steering pump when the wheel is turned to the full right or left position when the vehicle is parked, it may be caused by the relief valve vibrating within the pump. In lieu of replacing the power steering pump, the relief valve is now available as a replacement part."

Here's where I'd look for the problem:

First, when you had the leak, after installing the new O ring, along with spewing out the fluid, it also sucked in a bunch of air. My recommendation is that you jack up the front wheels off the ground, top off the reservoir and with the engine off, turn the wheels lock to lock a bunch of times - slowly! After doing this about 10 times or more, start the car only for a few seconds and shut back down. Then, go back through the lock to lock procedure. If you have someone to help, have them watch for bubbles coming into the reservoir.
This takes a while but it works. Do this before you drive the car. Like first thing of a morning - just not right after you've pulled into the driveway. Microbubbles form because the air is pressurized and it takes a while to work those out of the system.

The other thing to check is where the suction hose connects to the pump. They have a tendency to get dry and brittle over time and that contributes to suction leaks which leads to air in the system.
My suction hose is dry, but not brittle. It is definitely much harder than my radiator hose.

I actually pulled the power steering pulley and used that to cycle fluid through manually.

I had an assistant turn the wheel for me, saw lots of microbubbles and had the fluid level rise to the point of almost overflowing.

Are you saying the microbubbles were because the car had been driven recently? I parked it about 3 hours ago...
 

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Twilight Blue 2015 3.6R with Eyesight
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All good advice! I'll never forget when this happened to my 2009. All I did was replace the belts. Once I was finished, I started the car to make sure everything was kosher.
Everything seemed fine, until I went to go somewhere. As I was backing out of the drive, the PS pump started squalling like crazy!
I immediately pulled back in and shut the car off.
To my shock and horror, when I opened the hood, PS fluid was all over the place!
I started the car again, and as my wife turned the wheel, PS fluid stared spewing into the tank and was coming out of the vent on the cap.
It was a bloody mess, LOL! I replaced the belt with a shorter one, bypassing the PS pump, and drove it to the dealer. They replaced it, under warranty, and the brand new pump did the same thing a week later! They replaced it, again... I have a feeling that they had a bad batch of PS pumps... LOL!
Knock on wood, I'm so glad that my 2015 has electric PS...
 

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06 Outback 2.5i
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Discussion Starter #10
The second bleeding attempt was a little more tedious, but I had a much better outcome.

After waiting about 30-45 minutes after the first attempt, I had my assistant turn the steering wheel slower this time, lock to lock. She probably did 15-20 turns, then I turned the pulley by hand, both directions. There was nowhere near the same amount of bubbles/microbubbles/foam was coming out. I had her do another 15-20 turns, then I put the P/S belt on. I had her turn the wheels straight and run the engine for 30 seconds. Then did another 15-20 turns. Then run the engine for another 30 seconds. Then another 15-20 turns. Then, started the engine and did 15-20 turns, holding at full lock for a few seconds before returning.

The squeal was gone. The reservoir level stayed steady at full lock. I could hear the engine run a little harder at full lock, but no strain/squeal from the PS pump.

I did the whole routine a few more times, just to be sure.

Hoping the squeal is gone now...
 

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2005 Outback R LL Bean 3.0 H6 w/ 5 speed sport shift
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597 Posts
The second bleeding attempt was a little more tedious, but I had a much better outcome.

After waiting about 30-45 minutes after the first attempt, I had my assistant turn the steering wheel slower this time, lock to lock. She probably did 15-20 turns, then I turned the pulley by hand, both directions. There was nowhere near the same amount of bubbles/microbubbles/foam was coming out. I had her do another 15-20 turns, then I put the P/S belt on. I had her turn the wheels straight and run the engine for 30 seconds. Then did another 15-20 turns. Then run the engine for another 30 seconds. Then another 15-20 turns. Then, started the engine and did 15-20 turns, holding at full lock for a few seconds before returning.

The squeal was gone. The reservoir level stayed steady at full lock. I could hear the engine run a little harder at full lock, but no strain/squeal from the PS pump.

I did the whole routine a few more times, just to be sure.

Hoping the squeal is gone now...
That's great news!

I learned this technique from another forum member.

I forgot about another posting where I talked about removing the belt....

I have had so much help from other members that I want to pay if forward when I can! This forum is an invaluable resource for any Subaru owner!
 

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06 Outback 2.5i
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Discussion Starter #12
So, the whine's started picking up again. Did the bleed procedure again, there were definitely more foam/microbubbles.

How important is it that the motor/system is cold before bleeding?
 

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2009 OB 2.5i 4EAT
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So, the whine's started picking up again. Did the bleed procedure again, there were definitely more foam/microbubbles.

How important is it that the motor/system is cold before bleeding?
The issue is if you have air in the system, the pump tends to dissolve it into fine bubbles that take considerable time to completely assimilate. Doing it first thing in morning is best option. Otherwise I'd wait an hour... I was doing 30 minutes for a while but seems it's a little short (for comparison, FSM recommends 12 hours on the H6).

Some people seems to imply bleeding this systems is easy, but I think in cases of serious air impregnation/part replacement, it isn't so easy. A vacuum pump would be nice. In anycase, it sounds like you're sucking in air somewhere.



The targets SHOULD be either the reservoir, suction hose, or pump ( and the connections between) as they all exist on the non-pressurized side of the system. The reservoir could have a crack. The hose could be brittle and not seal well on either side. The tension on the hose/bolt torque could cause improper seating on the pump (it is an absolutely terrible design, watch how much you can move the suction connector by tugging up and down on the hose... do you have the original double ziptie connector binding the suction hose with the pressure hose?). The pump could be sucking in air via old o-ring (you could try tightening the pressure sensor, relief valve cap, and the 4 bolts holding it together).



I'm interested in what ends up working for you. I've been battling this issue for almost 6 months, however with issues in steering feedback and power.
 

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06 Outback 2.5i
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Discussion Starter #14
The issue is if you have air in the system, the pump tends to dissolve it into fine bubbles that take considerable time to completely assimilate. Doing it first thing in morning is best option. Otherwise I'd wait an hour... I was doing 30 minutes for a while but seems it's a little short (for comparison, FSM recommends 12 hours on the H6).

Some people seems to imply bleeding this systems is easy, but I think in cases of serious air impregnation/part replacement, it isn't so easy. A vacuum pump would be nice. In anycase, it sounds like you're sucking in air somewhere.
Ok, I took the motorcycle to work today, so the car was sitting for at least 24 hours before I started bleeding it. My very patient helper sat in the car and slowly turned the wheel for about 30 minutes. There were still few bubbles and microbubbles coming out of the reservoir. I had her run the engine for 30 seconds, turn the wheel for another 10 minutes, then run the engine and turn the wheel some more.

Sounds like I either have a ton of bubbles to bleed out or some type of leak?

The targets SHOULD be either the reservoir, suction hose, or pump ( and the connections between) as they all exist on the non-pressurized side of the system. The reservoir could have a crack. The hose could be brittle and not seal well on either side. The tension on the hose/bolt torque could cause improper seating on the pump (it is an absolutely terrible design, watch how much you can move the suction connector by tugging up and down on the hose... do you have the original double ziptie connector binding the suction hose with the pressure hose?). The pump could be sucking in air via old o-ring (you could try tightening the pressure sensor, relief valve cap, and the 4 bolts holding it together).
None of those items appears to be leaking fluid. The reservoir level stays consistent, no matter what. I could never find a torque spec on the bolt for the suction hose (top of the ps pump hose). The o-ring on top of the bolt for the suction hose has been replaced.

The original double ziptie is broken.

Do you mean the 4 bolts holding the pump together?
 

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2009 OB 2.5i 4EAT
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@jamesm113 Theoretically if you do not have a suction leak, once bubbles are gone they stay gone. If you're not having issues related to force required to steer, feedback over bumps, bouncing, etc. I'd leave it alone, maybe replace the pump if the sound is intolerable. But if you have a significant suction leak, there's no reliable way to locate the source. Fluid leaks are easy!

And yeah, there's seven spots that could be tightened on the pump. 4 hold the halves together (you'll need to pull it from the mount to do it). The pressure sensor (cable on the back, 17mm nut I think). Pressure relief valve (one with the like 8mm allen key). And the ~17mm bolt on the side which holds a spring which tensions a part of the assembly. All of these points are couplings with o-rings and could conceivably suck in air or leak fluid. There aren't any torque specs AFAIK, but it's aluminum so don't go crazy.
 

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03 H6 OBW & 06 WRX Sportwagon
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on my cars, there's no o-ring associated with a bolt, it's on the adapter that sticks down in the top of the pump.

air can aslo get in past a crack in the suction hose or past the clamped ends. I read once of a reservoir having a crack near the suction hose 'nipple'.


There is also a TSB concerning a pressure relief valve in some models' pumps.


If you feel confident the source isn't the hose or it's connections, get a used pump from a wreck.
 

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06 Outback 2.5i
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Discussion Starter #17
Said f it and took a $40 gamble on a new suction hose. Sure enough, the old suction hose had a crack, and the 4 notches from the pump inlet were digging in significantly.

Started the bleeding process, but it's slow going. Decided to let the car sit overnight now.

I forgot to order the ziptie thing to hold the hoses together. Is that worth replacing?
 

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2008 Outback H6
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I was having the same power steering noises. My O ring was squared off, but didn't show any signs of cracking. For $2 I went ahead and replaced it anyways. As soon as I was done, the noise got way worse. Turns out, the hardened suction hose had cracked once I started moving it around. Replaced the hose and all is well now. Took a few drives for the bubbles to completely dissipate but its quiet.
 

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I’ve been following this post hoping to find an answer, and I appreciate everyone’s responses thus far.
I have an 08 Outback with PS fluid collecting just below the pump on top of the engine. I have replaced the hoses and the o-ring on the top cap from the hose that goes into the pump. Any ideas of where else I might have success finding the leak? Could it possibly leak where the wire exits on the side of the pump? Thanks
 
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