Parts for your 2008 Subaru Impreza-Power steering pump

2008 Subaru Impreza Power Steering Pump

Based on technical references including the Subaru Factory Service Manual for the 2008MY Impreza/WRX (Steering section), Subaru’s official parts catalogue for GE/GH/GR models, and mainstream workshop data sources such as Autodata and ALLDATA, the 2008 Subaru Impreza uses a belt-driven hydraulic power steering pump. Electric power steering didn’t arrive on Impreza until later generations, so this model relies on a traditional hydraulic setup.

On this Impreza, the power steering pump does the hard yakka of pressurising fluid so steering effort stays light at parking speeds and stable at highway pace. It draws fluid from the reservoir, pushes it through the steering rack, and helps the wheel return to centre smoothly. When it’s healthy, turning feels consistent and quiet, when it’s crook, you’ll often hear a whine, feel heavy or jerky assistance, or spot leaks around the pump, hoses, or reservoir.

As part of regular servicing, it’s smart to keep an eye on a few basics. Use an ATF that meets Dexron III specifications, as Subaru specifies ATF for this hydraulic system rather than generic “power steering fluid”. Check the fluid level and colour—low, dark, or foamy fluid points to leaks or aeration. Inspect the drive belt for cracks and proper tension, and look over hose clamps and the pump’s front seal area for weeping. Many Subarus of this era can ingest air via a tired reservoir O-ring on the suction side, which can cause cold-start pump whine, replacing that O-ring is a cheap, high-impact fix.

If replacement is on the cards, a quality remanufactured or new pump matched to the correct engine variant is the way to go. Always flush the system to clear debris and old ATF, replace the suction O-ring, and bleed the system by turning lock-to-lock with the front wheels off the ground and the engine idling—watching for bubbles in the reservoir until they’re gone. Over-tightening the belt can shorten pump bearing life, so set tension to spec. A tidy install and fresh fluid will usually keep the steering sweet for years.

• Service tip: check fluid and belt every 10,000–15,000 km.
• If you hear whine after cold starts, inspect the reservoir O-ring and suction hose first.
• Use only Dexron III–spec ATF and bleed thoroughly after any work.

FAQ: What fluid should go in a 2008 Subaru Impreza power steering system?
Subaru specifies ATF meeting Dexron III for this hydraulic system, not generic “power steering fluid”. Using the correct ATF helps minimise pump noise and protects seals. After topping up or a flush, bleed the system by slowly turning the wheel lock-to-lock with the engine idling until no bubbles appear.

FAQ: How can someone tell if the power steering pump is failing?
Common signs include a whining or groaning noise that changes with engine speed, heavier-than-normal steering effort, pulsing or notchy feel at low speed, foamy fluid in the reservoir, or visible leaks. Rule out a loose or glazed belt and air leaks at the reservoir hose before condemning the pump.

FAQ: How long do these pumps last and what does replacement involve?
Many last well beyond 150,000 km when fluid is clean and the belt is set correctly. Replacement typically includes swapping the pump, renewing the reservoir suction O-ring, flushing the system with the correct ATF, and bleeding thoroughly. Labour and parts costs vary across Australia and New Zealand, genuine or high-quality reman pumps are recommended for longevity.