As the title says, a simple fix here for what I was worried might be a more costly and involved job of replacing the power steering pump.
The symptoms were a whining/whirring noise when maneuvering the Forester in the driveway or when parking so when going from lock to lock. This began happening on cold mornings more in particular.
After a quick interweb search I found these symptoms were a pretty common Subaru problem and the fix is cheap and simple which is always nice! The power steering pump becomes noisy simply because air is getting into it. There are two common causes of air getting into the pump. One is via an O-ring and the other is via a hose. Both being rubber and getting regularly heat cycled, they can harden over time and therefore not seal as well as they should which allows a small amount of air to be sucked in with the fluid by the pump which makes it a bit noisy.
If the cause is just the hose that feeds the pump then the fix can be as simple as adding a better hose clamp to the pump end of the hose. I tried this and it fixed the problem straight away. I could have left it at that but that’s not really my style and might only be a temporary fix.
So I ordered a genuine Subaru replacement hose and O-ring. As you can see I actually bought 2 O-Rings as there were two options and I wasn’t sure if they were actually different so just bought both. They appear to be exactly the same so either would have been fine. Also some new power steering fluid.
O-Ring: 34439AE020 / 34439AE021
On with the job.
Here’s the hose in question. I’ve started removing the additional hose clamp I fitted that fixed the problem.
Now to carefully remove the reservoir and empty it into something.
Old and new hose. New one looks the same, good news.
Here’s where the O-ring hides.
The old O-ring, very flattened off.
This bracket for the fluid reservoir looked pretty ropey so I cleaned it up and gave it a few coats of paint.
While I was here I fitted a new AC pump belt too, as the existing one didn’t look great.
This was a bit tricky to undo so needed a bit of freeing up off the car.
That’s a couple of jobs done. Nothing but a perfectly quiet power steering pump now, even on the coldest mornings, as it should be.