While the lines and tanks may be slightly different, the theory should apply to most cars.
I did the suction and fill method on my 2000 a long time ago and it actually worked well. This time I wanted instant gratification, so after some searching I found a DIY on legacygt.com by Killer Deer. Here is his walkthrough:
The service manual is vague and recommends a very complicated way to do it, and I couldn’t find any good instructions for Subaru’s.
To do this you will need at least 1 box of oil. I used some leftover Valvoline ATF to flush before repeating the procedure with 1 qt of Mobil 1 Synthetic ATF Dexron III.
1. Loosen/remove the front accessory belt so you can rotate the power steering pump with your finger. Since most of us don’t have a belt tensioner, you can mark the thread of the tension bolt (on the top side) or feel the deflection by hand and adjust this when you put it back on.
2. Attach the front of the car to the center point of the jack so that the tires are just off the ground and the steering wheel can turn freely with the engine off.
3. Pull the hard top line (return line) from the power steering fluid reservoir (On the GT this has some aluminum fins for cooling), this will allow you to turn it forward and fit a catch pan for the oil liquid below it.
4. Turn the power steering pump clockwise by hand. Dirty liquid will exit the return line. Keep spinning until the tank is basically empty and you can add new fluid. Try not to completely empty it, however it’s not the end of the world if you do, as it will bleed itself, and this procedure itself will bleed the air out of the system.
5. Add new fluid to the reservoir to the top (past the maximum). Repeat step 4 until new, clear fluid comes out of the return line.
6. Insert the key and turn it so that the steering wheel is unlocked, but DO NOT START the engine.
7. Making sure the reservoir is full, turn the steering wheel from lock to lock using slow steady pressure, taking a few seconds to do so. The liquid will be pushed off the rack and into your catch pan. A full tank is good for at least one full block. The fluid that comes out will return to the old fluid and then to the new fluid.
8. After going from lock to lock at least once left and once right, repeat the last step until no old fluid comes out, once this happens, be sure to leave the reservoir at “COLD MAX” or by add and remove liquid by rotating the pump.
9. Refit the return line and accessory belt.
Check the tank level after the next few moves. If you put air in the lines, it will fall out, so refill it. END
My 07 is a little different in the hose department. It was easiest for me to use a length of hose I had laying around and disconnect the return hose to the hard line (see photo)
Here’s what I did:
Remove the engine cover
Remove the power steering belt
Remove the power steering return line to the hard line
Connect the length of hose to the solid line. The other end goes into a catch container. The power steering hose you removed should just be higher than the tank.
Turn the power steering pump pulley clockwise, it took a few turns to get it pumping for me. Pump most of the liquid into the residue… Try not to let it dry out.
Fill the res and continue to pump until the liquid comes out clear from the hose.
Center the car (both front wheels slightly off the ground)
Complete res full.
Turn the key on, don’t start, unlock the steering wheel
Turn the steering wheel lock fully to the right, slowly. It will pump the fluid through.
Complete the res
Slowly turn the steering wheel to the left
Repeat at least once more.
Lower car.
Adjust the level to full cold res by pumping out with the pump pulley.
When removing the hose, hold your finger over the other (vacuum) end and use a cloth to pick up any drips.
Reattach the hose and belt.
