Power Steering Q

chickenlover

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Joined
Nov 26, 2008
Messages
93
In the last few days the Power Steering in my OB (01) has started playing up. I.e. not smooth at slow speeds; juttery at full lock; making a few squeeks...

Like you would expect if she had low oil...but the oil level is fine, not leaking, not open to crud.

So im thinking maybe the oil is past the used by date and/or I just need to flush and bleed the system to clean out accumulated crud - just like a brake system.

Does this sound fair? Any other suggestions? Any tips for bleeding the system?

Cheers
 
check the belts. Look for leaks at the rack.

you never really have to change this fluid, but if you do, you blead it by turning the wheels to full lokc avout 20 times.


nipper
 
For an MY'03 Foz - should be similiar

C: REPLACEMENT​
1) Lift up the vehicle.
2) Remove the jack up plate.
3) Remove the pipe joint in center of gear box, and
then install the vinyl hose to pipe and joint. Drain
the fluid while turning steering wheel.
4) Set the ST on top of reservoir tank and fill it
about half way with the specified fluid.
ST 34199AE040 OIL CHARGE
5) Continue to turn the steering wheel slowly from
lock to lock until bubbles stop appearing on oil surface
while keeping the fluid at that level.
6) If turning the steering wheel in low fluid level
condition, air will be sucked in pipe. In this case,
leave it about half an hour and then do the step 5)
again.
7) Lift up the vehicle, start the engine and let it idle.
8) Continue to turn the steering wheel slowly from
lock to lock again until bubbles stop appearing on
oil surface while keeping the fluid at that level.
It is normal that bubbles stop appearing after three
times turning of steering wheel from lock to lock.
9) In case the bubbles do not stop appearing in the
tank, leave it about half an hour and then do the
step 4) all over again.
10) Lower the vehicle, and then idle the engine.
11) Continue to turn the steering wheel from lock to
lock until bubbles stop appearing and change of the
fluid level is within 3 mm (0.12 in).
12) In case the following happens, leave it about
half an hour and then do step 8) to 11) again.
(1) The fluid level changes over 3 mm (0.12 in).
(2) Bubbles remain on the upper surface of the
fluid.
(3) Grinding noise is generated from oil pump.
13) Check the fluid leakage after turning steering​
wheel from lock to lock with engine running.
 
Thanks guys!

I havent seen a leak but ill do a proper inspection tomorrow.
By checking the belts I assume you mean to check for wear, tension...

I found my dodgy ebay sourced electronic vehicle manual and is basically word for word to yours Kevin.
 
Gee Nipper, I don't know of any oil that does not need changing- especially oil that goes through as many heat cycles and as much pressure as the ATF in power steering fluid. I change mine every 12 months, flushing every 2 years.
 
Rally said:
Gee Nipper, I don't know of any oil that does not need changing- especially oil that goes through as many heat cycles and as much pressure as the ATF in power steering fluid. I change mine every 12 months, flushing every 2 years.
Click to expand...

It doesn really need chaninging. It has minimla lubricating properties. It is only used to push mechanial force. Is sees no stresses from the life it leads. Remeber this is the same fluid that is in your auto tranny with 90% less work.

It doesnt even really see a heat load nor shear forces like the tranny fluid. If a dealer tells you to change it, they are looking for a rediculous amount of money for what is essentially a fluid that lasts the life of the car.

PS fluid is the least important fluid in the car, and generally no one changes it. It being a hydraulic fluid, it also gets refreshed by adding new fluid to it. Back when we had recirculating ball steering that fluid saw some work. Even big cars there were even mini coolers in the PS line. With Rack and pinion it has a very sheltered life.

Here in the US subaru doesnt call for chainging it.
https://www.cars101.com/subaru/subaru_maintenance.html

nipper
 
Heat must be an issue as far as the factory sees it because on some models they come with a power steering cooler as standard- my WRX has one. A number of cars in our club have had issues requiring an upgraded cooler due to overheating the fluid- and since upgrading the cooler have had no issues.
 
It can be just to rid the heat from underthe hood. But like i siad (i am an automotive engineer by trade) it really sees very very low stress. 95% of the cars on the road never get it changed, and really dont have any unusual failures or issues.


My car needs a PS pump right now, but at 250,000 miles its due (the front bearing).

nipper
 
...I cant see how it wouldnt need changing and more importantly the system needing flushing periodically.
Im thinking of how a brake system works - its a sealed system and in theory the fluid shouldnt degrage and maybe it doesnt, but the system certainly attracts a significant amount of crud that needs flushing which fould the fluid and system operational capacity.

I have no leaks in my system and I cant remember if ive even needed to top it up over the past 100 000k's. So im guessing there is crud in the system somewhere... when i pull the finger out and flush it ill let you know

Cheers
 
It is a bit different with brakes, but all oils are chemicals and as any chemist will tell you, they break down with age. Another property of brake fluid is that it is hydroscopic, which means it absorbs fluid. With the power steering systems I have seen, there has been a change in fluid colour. This can be because of the dye in the fluid, but it can also tell a different story. I would not expect to find much crud in the power steering system. However, on some model Subaru's, the power steering lines pass very close to the turbo and when you have the kettle that close to the stove it won't take long to boil a brew.

My background in this matter is in motorsport- both in rally at international level and circuit racing at club level (both with Subaru's) where these issues have become apparent. In that environment, you are always changing all fluids as a matter of course. You come back from that for street use of course but at the end of the day fresh fluid can only do good.

As Nipper has noted some cars can go incredible distance with no maintenance at all while others turn up their toes after only a short time. My preference is to give the poor old thing every chance to get to old age by making life easy for it.
 
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