1999-2001 Subaru Impreza Power Steering Pump: Fixing Whines, Leaks, and Stiff Steering

Is Your Impreza's Power Steering Whining? Check This First!

Symptoms of a Failing Power Steering Pump

When a power steering pump begins to fail, it gives several distinct warning signs. While the O-ring is a common culprit for noise, other symptoms may point to a worn-out pump or other issues in the system.

Whining or Groaning Noises

This is the most frequent complaint. You'll hear a whining or groaning sound that rises and falls with the engine's RPM. The noise will typically get much louder when you turn the steering wheel. This is caused by air in the fluid (aeration) or by the internal components of the pump wearing out.

Stiff or Heavy Steering

If the steering wheel becomes difficult to turn, especially when parking or driving at low speeds, the pump is likely not generating enough pressure. This can happen intermittently at first, with the power assist cutting in and out before failing completely.

Fluid Leaks

Finding puddles of reddish or light brown fluid under the front of your car is a sure sign of a leak. The pump can leak from its main shaft seal or housing. However, it's also critical to inspect the high-pressure and low-pressure hoses and their connections, as these can also become brittle and leak over time.

Bubbly or Foamy Fluid

If you check the power steering fluid reservoir and the fluid looks foamy or has a lot of bubbles, it confirms that air is entering the system. This could be from the infamous suction O-ring, a cracked hose, or a loose hose clamp. Running the pump with aerated fluid will lead to noise and can cause permanent damage.

Known Issues, Recalls, and TSBs

For the 1999-2001 Subaru Impreza, there are no specific recalls issued by the National Highway Traffic Safety Administration (NHTSA) for the hydraulic power steering pump. Any recalls you may find online are typically for newer Subaru models equipped with Electronic Power Steering (EPS) systems, which are completely different. The most significant known issue for this generation is the tendency for the suction inlet O-ring to fail, as detailed throughout this guide.

Buying a Used 1999-2001 Impreza Power Steering Pump

A low-mileage, used OEM power steering pump is often a more reliable and cost-effective choice than a cheap aftermarket or remanufactured unit. Aftermarket pumps can have a higher failure rate, sometimes due to improper installation, but also due to lower quality control. Here’s what to look for when buying used:

• Physical Inspection: Check the pump housing for any cracks or significant corrosion. Ensure the inlet and outlet ports and their threads are clean and undamaged.
• Pulley Check: The pump should include the pulley. Spin the pulley by hand. It should rotate smoothly with a slight resistance but without any grinding noises, wobbling, or excessive play. A noisy or wobbly pulley indicates a bad bearing.
• Verify Compatibility: This pump (OEM Part # 34411AC061) fits both the 2.2L and 2.5L engines in the 1999-2001 Impreza. However, always double-check the part number from the donor vehicle if possible. Fitment for 1998 models can vary, so VIN verification is recommended for that year.
• Mileage and Source: Ask for the mileage of the donor vehicle. A pump from a vehicle with under 100,000 miles is a good candidate. Buying from a reputable salvage yard with a warranty is always a smart move.

Cost Comparison

Prices can vary based on location and supplier, but this provides a general cost expectation for the part and associated labor.

Replacement Overview & Critical Steps

Replacing the power steering pump is a manageable DIY job for those with mechanical experience. The difficulty is moderate, primarily because the fluid bleeding procedure must be done perfectly.

1. Drain the Fluid: Use a turkey baster or fluid extractor to remove as much old fluid as possible from the reservoir.
2. Remove the Belt: Loosen the 12mm locking bolt on the alternator and then loosen the tensioner bolt to create slack in the accessory belt, then slip it off the power steering pump pulley.
3. Disconnect Hoses: Disconnect the low-pressure suction hose and the high-pressure line from the pump. Be prepared for fluid to spill and use rags to protect the alternator below.
4. Unbolt the Pump: The pump is held to the engine by a bracket with two 12mm bolts. Remove these bolts and lift the pump and bracket assembly out of the car.
5. Swap Components: On a workbench, transfer the mounting bracket and pulley from the old pump to the new one.
6. Install New Pump & Hoses: Bolt the new pump assembly into the car. This is the perfect time to install a new suction O-ring and new suction/return hoses if they are old and hard. Reconnect all hoses and the accessory belt. Torque the bracket bolts to approximately 16 ft-lbs.

Critical Step: Bleeding the System

Failure to properly bleed air from the system is the #1 cause of a noisy, short-lived replacement pump. Do NOT start the engine until this is complete. 🎬 Watch: How to properly bleed a Subaru power steering system

1. With the front wheels lifted off the ground, fill the reservoir to the 'COLD' mark.
2. Slowly turn the steering wheel all the way to the left, then all the way to the right. Repeat this process 20-40 times. You will likely see bubbles in the reservoir and the fluid level will drop. Keep topping off the fluid as needed.
3. Once the fluid level is stable and bubbles are gone, disable the engine from starting (e.g., by pulling the fuel pump fuse). Crank the engine for a few seconds. Check the fluid level again; if it drops, more air has been purged. Repeat the wheel-turning process.
4. When the fluid level is completely stable, reconnect the fuel pump fuse, start the engine, and check for noise. Let the car run and turn the wheels a few more times, then shut it off and perform a final fluid level check.

Frequently Asked Questions (FAQ)