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Discussion Starter #1
I was looking at continuing an already active or old thread but couldn't find one that has discussed this alone. So I’m trying to consolidate some info here and continue further.
I had a whining noise from my steering pump from day one. Bought the car less than a month ago and asked the agent to check this before I took delivery – the mechanic said it was fine – but it isn’t. I will be following this up with the agent soon but would like some info in the meantime.
First I did a oil flush with specified Dextron III spec oil. See here: http://legacygt.com/forums/showthread.php/howto-replace-power-steering-fluid-15-minutes-172976.html Easy job. He I can just add that I found it easier to remove the reservoir from the body for easy access to the return pipe and to block the return pipe hole in the reservoir easier as not to leak when you fill the it during the flush.

I was hoping this would resolve the whining but it didn’t.
I searched as little more and looks like there might be a replacement part for the relief value. http://www.subaruoutback.org/forums/491437-post8.html This could save some money if I don’t have to replace the whole pump. Now my pump is leaking an bit as can be seen from the video so I would need some seals as well. Can anyone elaborate on the relief valve replacement please? Maybe a technical parts sketch of the pump?
Listen to noise here:
Subaru 3.0R Power steering noise - YouTube
 

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03 H6 OBW & 06 WRX Sportwagon
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It's my understanding the relief valve only helps with noise at the extreme 'lock' position.

Do you have bubbles in the PS reservoir while idling? If not, you should pursue checking the serpentine belt's tensioner and idler pulley bearings (search for that issue) as possible sources of the noise. The last thing I would do is replace the PS pump. Not saying it's impossible to be the culprit, just less likely than air in the system or bad pulley bearings.

The sound in that video was not much like I recall the sound my pump was making. Though, the speakers on this system where I work and the device the sound was recorded on may make it hard to know for certain.
 

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2007 Outback 2.5i MT
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My car is also making this exact noise. It doesn't really get louder when I turn the wheels at idle, but my car does seem to drop in power momentarily.
 

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03 H6 OBW & 06 WRX Sportwagon
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look in the reservoir while idling. Seriously, it's 2 10mm bolts I think to pull the intake, then remove the cap. No bubbles or foam, then it's definitely not air in the PS. That removes one of the primary sources of noise from that area. next is idler and tensioner bearings.

both problems have happened many times here and is why there are stickys and many posts for them.
 

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Discussion Starter #6
It's a 2006 model.

Cannot be the serpentine belt's tensioner and idler pulley bearings - they were replaced 20 000 kms back.
I'll check for bubbles again - did not see any before.
I'm going to hose down the pump with engine cleaner and wait a while (weeks) to see where the oil leak is originating. Will then be replacing the o-ring seals on the suction pipe.
 

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01 Outback H6 VDC, 97 GT wgn w/ ej22, 98 OBW w/ej22
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are the rack boots torn?
do you have any oil stains on them?

the 06 set up is slightly different than 00 - 04 or 95 - 99.
but it obviously has the reservoir separate from the pump, same as 00-04.

the common leak points are where the lines connect to the rack, the rack boots (= a bad rack, not really common) or the line between the tank and the pump.

could it be that the fluid had not been topped off in ''years''? and was just low, not really leaking?
 

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2005 XT, Mildly Modified...2006 XT Limited, Highly Modifed
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Check to see if there is any tension on pressure hose anywhere. Also, there are two clamps for the pressure/return lines, one is t the back of then engine, down low. The other, you have to access from under the car, it's in a hole in the sub-frame. Check that the clamps and lines are all good, not loose or tweeked. There was a SB or something, maybe on the LGT forum, about tension in the lines causing a noise and a shudder. Might be good to check for any road/debris damage to any of the lines that run along the rack.
 

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03 H6 OBW & 06 WRX Sportwagon
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I had PS fluid 'leak' because it was foaming severely enough to push out the top of the reservoir. Though that was not near the pump on our 03 OBW.
 

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Discussion Starter #10
I am fairly confident that is is the pump alone. The sound is coming from the pump and not the lines. I will check the rack boots thanx. There is a leak visible on the pump. Looks like it is concentrated on the back but it could just be because of run-down from the top. See photo. Is the O-ring (34439AE020) the one that fits to the top line entering the pump? Is there any other seals that might lead to the leak I see here?

 

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Did you see bubbles in the reservoir while the car is idling?

It does look more like a pump seal or a high-pressure line is leaking. I didn't have any oil on my pump, just on the PS fluid tank. Also, i THINK there's an engine oil pressure sender on the block not too far away from there so, maybe there's 2 problems, leaking pressure sender AND air in the PS system?
 

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Discussion Starter #12
I'll look for bubble this afternoon and check out the sensors like you say. Also going to clean it up a bit and maybe take some more photos.
What sensor is on the back of the power steering pump?
 

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03 H6 OBW & 06 WRX Sportwagon
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I dunno how it works, but there is a connector for speed-sensing so you get better road feel on the highway, more power assist at parking lot speeds.
 

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Discussion Starter #14
Cleaned the old oil from the pump. Looks like the o-ring to me as the streaks of old dry oil that started from this part of the pump was the hardest to get off. I will get an o- ring tomorrow. Its definitely not the oil sensor on the engine cause this one is clean.
My wife is driving the car. So as I worked I realised that the past 3 days of driving (oil circulated well) has made an noticable improvement to the sound. Its much better and almost concentrated to the full lock position. So if the o-ring doen't work I will look as the relief valve again.
Still need to check the steering boots
 

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Discussion Starter #15
I've been driving a while now after the oil replacement. Sound is basically gone except when at full lock. I must still replace the o-ring.
Amazed at how much difference an oil change can do!
 

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Discussion Starter #16
So after cleaning off the pump a while ago with engine cleaner and high pressure, I inspected the pump over the weekend again. Looks like the sweating has its origin at the back of the pump at the speed sensor. How would one go about in stopping this?
Not sure if this is the cause of the noise originally seeing that the noise has now been reduced so much and only audible when at full lock. But now I know if the leak and would like to sort it out.
 

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Onyx, 2008 LL Bean 3.0R and 2017 Honda Civic Hatchback Sport Touring
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If the sound increase in pitch with acceleration it may be the pulley bearings. The previous owner may have overtightened the serpentine belt torquing the bearings which can cause their failure. I noticed your alternator looks new in your pic above. If, like my 2nd gen 2.5 and the alt uses the same belt as the PS pump, they may have replaced the alt because it was making a similar noise due to trashed pulley bearings caused by someone cranking down on the belt in the hopes of improving PS performance or just a lack of knowledge. So now it may be time for a new PS pump or pulley for the same reason the alternator was replaced.
 

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Discussion Starter #19
The serpentine belt and tensioner pulleys were replace by the dealer 20 000km back. The current tension on the belt is to spec (see photo – sorry for the mess). I have a full service record en confirmed this with Subaru SA (got all the invoices) – the alternator was never replaced.
The sound is much better and only limited to the full lock position. And I hear nothing from the pump during driving – only the lovely H6.
Found out from my local dealer, the relief valve is available but needs to be imported. I’m going to get it because it’s not that much $$. I would love an illustration or photo of the value and where it’s situated (where are all the clever parts fiche guys?)
From the previous photo it looks like the speed sensor has a circlip that can be removed and possibly then a seal/o-ring that could be replaced. Could this be available?
According to the SA fiche, the pump is a sealed unit and no parts available. I would love to try and fix it.
 

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Groaning at the limits was the subject of the attached Technical Service Bulletin issued by Subaru of America. I can't say whether or not it applies to the power steering pumps installed by Subaru in cars made in Japan.

That connection at the back of the power steering pump is not to a speed sensor. It's to a pressure switch that signals the engine control module when the pump is under load. The ECM increases the engine speed to prevent engine hesitation and better accommodate the load.

According to the SOA factory service manual the pump is not serviceable; all to say that there's no information on replacing the pressure switch.

I don't recall seeing any reports here of leaks from the switch. But the pressure switch on my 07 p.s. pump appears to be different; it's screwed into the back of the pump with a hex head fitting -- there's no circlip.
 

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