what makes power steering go heavy?

[AWD]

I read all the power steering topics I could find, but this didn't seem to be discussed specifically: what is it that actually makes the power steering feel heavy? :smt017

I ask because the wagon used to randomly go from feeling really nice and light (usually - but not always - when you just start her up) to feeling heavy (usually after a min or two of driving) and staying that way for the rest of the trip. It was a really clear change - I'd sit there and think, "hey, what happened to the nice light feeling?"

This used to happen fairly regularly - the lightness never lasting more than a minute or two - but lately it's been heavy right from the start, and the light feeling has gone away altogether.

1. There is plenty of fluid in the reservoir
2. There are no strange noises - squeals, squeaks or otherwise - when you turn the wheel
3. However, the wagon's about 10 years old, and as she had only done 9000km over that time the power steering has never had a service

What can I do to bring back the lightness?

[Huffer]

Drain the p/s system and refill it with clean fluid. You will need to "burp" the system though to remove airpockets.
If that doesn't do it then you are probably looking at new bushings and a new pump.

[2.5GT]

You can't really "burp" the system like you do with the radiator.

Take it to Subaru, they should have a machine that can suck out all the fluid and refill with the fresh fluid.

I know in cold temp. I've experience a really hard-like non power steering feel. Once the car warms up, it went back to normal. Subaru steering tends to be a bit stiffer.

[Huffer]

You can actually burp it by turning the steering wheel several times lock to lock while the front end is lifted.

[2.5GT]

Yes, I forgot about that. And have the car running too.

[grayguy]

Is your steering "clunky" as I call it. Does it turn smoothly for part of a rotation, then get hard, then get good again? Does is not return to center? All of these things will happen when your Steering shaft U-joint is seived. The one in my 92' is and has been for about a month, and it really sucks.

[AWD]

ok, that's potentially good news. Was hoping it wasn't something major like the pump failing, although I guess it still could be if the drain/refill/burp doesn't work... Will add that to the list of things to do this weekend anyhow - thanks again!

No 'clunky' steering grayguy, although it's good to know what would cause that. Good luck with fixing yours - I thought the heavy steering was annoying, but that sounds like a real pain...

[darjeeling]

ok, that's potentially good news. Was hoping it wasn't something major like the pump failing, although I guess it still could be if the drain/refill/burp doesn't work... Will add that to the list of things to do this weekend anyhow - thanks again!

No 'clunky' steering grayguy, although it's good to know what would cause that. Good luck with fixing yours - I thought the heavy steering was annoying, but that sounds like a real pain...

Just FYI, I am replacing this Ujoint tomorrow. Got it from the dealer at $142. I have the exact same feel from my steering, and I'm using a new rack with new fluid, all de-bubbled. Alignment, new tires/wheels, new tie-rods, etc.

UPDATE: Worked perfectly. Was the cause of the heavy steering.