Parts for your 2005 Subaru Impreza-Power steering pump

2005 Subaru Impreza power‑steering pump

Technical sources confirm the 2005 Subaru Impreza uses a hydraulic power‑steering pump. The Subaru Workshop/Service Manual for 2005MY Impreza (Steering section), Subaru Technical Information System (STIS), and widely used aftermarket references such as the Haynes manual for Impreza/WRX all describe a belt‑driven hydraulic pump mounted on the EJ engine, feeding a rack‑and‑pinion steering gear via high‑pressure and return lines. So yes, a power‑steering pump is fitted and is central to steering assist on this model range, including WRX and STI.

The pump’s job is to push fluid under pressure to the steering rack so turning the wheel is light and predictable, especially at parking speeds. It’s driven by the accessory belt under the bonnet. When it’s healthy, the wheel feels consistent and quiet, when it’s not, you’ll notice heaviness, groans or whines, and fluid leaks.

• Common symptoms of a tired pump or system: whining on cold start, intermittently heavy steering, fluid foaming in the reservoir, visible leaks around hose connections or the pump body, and a belt that squeals under load.
• Typical causes: worn pump vanes/bearings, a hardened inlet (suction) O‑ring letting air in, old or contaminated fluid, loose or glazed drive belt.

For routine servicing, check fluid level and colour at each service. Subaru specified ATF meeting Dexron III for many models of this era, always verify on the reservoir cap or service manual. Keep the drive belt correctly tensioned and replace it if cracked or shiny. On these Subarus, the small inlet O‑ring is a frequent culprit for aeration and noise—cheap to replace and well worth doing if there’s any whine.

1. If fluid is dark or smells burnt, do a fluid exchange and bleed: front wheels off the ground, engine off, turn lock‑to‑lock slowly several times, top up, then start and repeat until bubbles clear.
2. If the pump leaks or whines after fresh fluid and a new O‑ring, consider a quality reman or new pump. Flush the lines, inspect the reservoir screen, and replace any weeping hoses to protect the new unit.
3. After any work, recheck belt tension and fluid level after a short drive, and look for drips at hose unions.

Looked after this way, the Impreza’s hydraulic steering stays light, quiet, and confidence‑inspiring on Aussie and Kiwi roads.

FAQs

What power‑steering fluid should a 2005 Subaru Impreza use?
For most 2005 Imprezas, Subaru specifies ATF that meets Dexron III. Check the reservoir cap and the steering section of the factory manual for your exact variant. Stick to one compatible fluid type and don’t mix brands excessively.

How do you bleed the power‑steering after a pump change?
Fill the reservoir to the mark, raise the front wheels, engine off, turn the steering slowly from lock to lock 10–15 times, topping up as bubbles purge. Start the engine and repeat until the fluid runs clear and quiet with no foam. Recheck after a short drive.

Why does the pump whine on cold starts?
Often it’s air being drawn in through a hardened suction O‑ring at the pump inlet. Replacing that O‑ring and refreshing the fluid usually stops the noise. Also inspect the drive belt and ensure it’s not loose or glazed.