How Long It Takes to Remove Air Bubbles from Power Steering

For most hydraulic power steering systems, removing air bubbles takes about 10–30 minutes using a standard bleed procedure; with a vacuum bleeder it can take as little as 5–10 minutes. Heavily aerated systems or those with underlying leaks may need 30–60 minutes or several short drive cycles, and if foaming persists beyond that, there’s likely a fault admitting air. This article explains typical timelines, the factors that affect them, proven methods to bleed the system, and when to suspect a leak or component failure.

Typical Timelines by Method

Depending on how you bleed the system and the condition of the components, the time required can vary. Below are common scenarios to set expectations.

• Standard bleed (front wheels raised, slow lock-to-lock turns): 10–30 minutes
• Vacuum bleeder method (Mityvac-style tool at reservoir): 5–15 minutes
• Heavily aerated fluid after a component change: 30–60 minutes plus cool-downs
• Self-bleed over multiple short drives: 1–3 trips of 10–15 minutes each
• If still noisy/foamy after 30–60 minutes: suspect a leak or pump drawing air

Use these ranges as a guide; always follow the vehicle manufacturer’s procedure because some systems specify engine-off initial cycles or other variations.

What Affects How Long It Takes

Several variables influence bleed time and whether the system clears quickly or stays noisy. Understanding these helps prevent wasted time and potential damage.

• Amount of air introduced: Replacing racks/hoses introduces more air than a simple fluid top-up.
• Reservoir design and hose routing: Poor return baffling or high loops can trap bubbles longer.
• Fluid temperature and viscosity: Warm fluid de-aerates faster but avoid overheating the pump.
• Pump condition: Worn vanes or seals can create cavitation and ongoing foaming.
• Leaks on the suction side: Any air ingress before the pump (loose clamps, cracked hoses) prolongs or prevents successful bleeding.
• System type: Hydroboost brake assist and some trucks/SUVs take longer; fully electric power steering (EPS) has no hydraulic fluid and doesn’t apply.

If variables stack against you—large component changes, marginal hoses, cold thick fluid—expect to be on the longer end of the range or switch to a vacuum bleed.

Step-by-Step: Standard Bleed Procedure

The following sequence suits many hydraulic systems after a fluid change or minor repair. Always verify the exact method in the service manual for your vehicle.

1. Safely raise the front wheels off the ground so they can turn without load.
2. Fill the reservoir with the correct, manufacturer-specified fluid to the cold mark.
3. With engine OFF (unless your manual specifies otherwise), slowly turn the steering wheel from stop to stop 10–20 times. Do not hold hard against the stops.
4. Let the fluid sit 2–3 minutes to release microbubbles; top up as needed.
5. Start the engine and let it idle. Slowly cycle the wheel lock-to-lock another 10–20 times, pausing near center. Watch for bubbles returning to the reservoir.
6. Maintain the fluid level; do not let the pump ingest air. If foaming spikes, shut off and wait 5–10 minutes.
7. Once noise and bubbles diminish, lower the vehicle and perform a brief road test with gentle steering inputs.
8. Recheck level and inspect for leaks. Repeat brief cycles if a small amount of hiss/bubble remains.

This method usually clears typical air pockets within 10–30 minutes. Avoid rapid steering inputs that whip more air into the fluid.

Vacuum Bleed Method (Faster and More Reliable)

Using a hand vacuum pump and an appropriate reservoir adapter speeds de-aeration and is recommended after major component replacement.

1. Attach a vacuum adapter to the reservoir cap or return port per your tool’s instructions.
2. Draw 20–25 inHg of vacuum and hold for 3–5 minutes to expand and release trapped air.
3. With vacuum applied, slowly turn the wheel lock-to-lock 10–15 times (engine off unless the service manual directs otherwise).
4. Release vacuum, top off fluid, then reapply vacuum and repeat once or twice.
5. Start the engine and maintain a mild vacuum (10–15 inHg) while cycling the wheel again.

Most systems will be quiet and bubble-free within 5–15 minutes using vacuum. If bubbles persist under vacuum, suspect a suction-side leak.

Signs You’re Done—and When to Worry

Knowing what “normal” looks and sounds like prevents over-bleeding and helps you catch real issues early.

• Normal end-state: No foam in the reservoir, quiet pump, smooth assist, stable fluid level.
• Temporary residual microbubbles: Fine haze that clears after a short drive—generally acceptable.
• Red flags after 30–60 minutes: Persistent foaming, growling pump, aeration streaks, fluid level fluctuating with bubbles.
• Common leak points: Low-pressure return hose clamps, reservoir-to-pump hose, pump shaft seal, O-rings on banjo/flare fittings, cracked reservoir.

If red flags remain, stop running the pump to avoid damage. Inspect the suction side for loose clamps or cracks, replace aged hoses, and reattempt a vacuum bleed.

Tips to Speed Up and Avoid Damage

A few practical steps can shorten the process and protect components during bleeding.

• Use the exact fluid spec (ATF vs dedicated PSF varies by make).
• Pre-fill the pump and any replaced hoses when possible.
• Keep the reservoir full; never let the pump run dry.
• Warm the fluid slightly (short idle) but don’t overheat; foaming worsens when hot.
• Avoid holding the steering against the stops; it spikes pressure and aeration.
• Replace spongy, oil-soaked suction hoses and suspect O-rings before bleeding.

Taking these precautions reduces aeration, shortens bleed time, and improves long-term reliability.

When Professional Help Makes Sense

If you lack a vacuum tool, see ongoing foaming after 30–60 minutes, or hear pump growl that doesn’t diminish, a shop can pressure/vacuum test the system, smoke-test for leaks, and verify pump/rack condition. This is often cheaper than replacing a pump damaged by running it aerated.

Summary

Most hydraulic power steering systems can be bled clear of air in 10–30 minutes with a standard procedure, or 5–15 minutes using a vacuum bleeder. Heavy aeration or underlying suction-side leaks can stretch this to 30–60 minutes or multiple short drives. If foaming and noise persist beyond that, stop and inspect for leaks or component wear before continuing, and follow your vehicle’s specific service guidance for best results.

Can I drive with bubbles in power steering fluid?

Problems with your vehicle’s power steering fluid can damage its power steering pump and steering gear. That’s why it’s best to avoid driving with foamy power steering fluid.

How long does it take for power steering fluid to start working?

Power steering fluid starts working almost immediately, but air trapped in the system after adding fluid requires a “bleeding” process to remove it. To do this, you should start the engine, slowly turn the steering wheel from full left to full right several times, and periodically check the fluid level in the reservoir to top it off as needed. This process usually only takes a few minutes of idling and a few turns of the wheel to expel air, but the system may need a short test drive to fully clear, as suggested on YouTube, on the first link. 
Immediate Action:

1. Fill the reservoir: Top off the power steering fluid reservoir to the correct level, ensuring not to overfill it. 
2. Start the engine: Turn the engine on and let it idle. 
3. Bleed the system: Slowly turn the steering wheel all the way to the left, then all the way to the right. Repeat this process 2-3 times. 
4. Monitor fluid level: Watch the fluid level in the reservoir and add more fluid if it drops. You may see bubbles, which are a sign of air being removed from the system. 

Why this works:

• Fluid circulation: The power steering pump circulates fluid throughout the system. 
• Air removal: Turning the steering wheel with the engine running helps push any trapped air out of the system and back into the reservoir, allowing the fluid to work properly. 

If steering is still stiff:

• Test drive: Take the car for a short test drive to further circulate the fluid and clear any remaining air bubbles, as recommended on Reddit. 
• Check fluid: After the test drive and the engine cools down slightly, recheck the fluid level and top it off if necessary, says Quora. 
• Professional help: If the problem persists, there may be a more serious issue, such as a leak or a damaged pump, and professional help may be needed, according to Quora and Highline Warren. 

How do you get rid of air bubbles in power steering?

To remove air from a power steering system, fill the reservoir, lift the front wheels off the ground, start the engine, and slowly turn the steering wheel from full left to full right about 15-20 times while keeping the fluid topped off. Do not hold the wheel at the stops. Shut off the engine, recheck the fluid level, and repeat the process until the fluid level remains stable and the system is no longer noisy.
 
Tools and Materials

• New power steering fluid
• Jack and jack stands
• Wheel chocks
• Vacuum pump (optional, for stubborn cases)
• Liquid vapor separator (optional)

Step-by-Step Guide

1. Fill the reservoir: With the engine off, fill the power steering reservoir to the correct level. 
2. Lift the vehicle: Use a jack to lift the front of the vehicle, ensuring the front wheels are off the ground. Place jack stands for safety and then position wheel chocks at the rear wheels. 
3. Start the engine: Start the engine and let it idle. 
4. Turn the steering wheel: Slowly turn the steering wheel from the full left position to the full right position and back again, repeating the movement 15 to 20 times. 
5. Check and refill the fluid: As you turn the wheel, the fluid level will drop; add fluid as needed to prevent new air from entering the system. Do not let the level get too low. 
6. Listen for noise: You may hear gurgling sounds as the air is pushed out of the system. 
7. Repeat if necessary: If the system is still making noise or the fluid level continues to fluctuate, repeat the process. 
8. Final check: Once the fluid level is stable and the noises cease, shut off the engine and recheck the fluid level one last time. 

If Air Persists

• Vacuum bleeding: Opens in new tabFor systems with stubborn air, a vacuum pump can be attached to the reservoir to draw air out while the engine idles. 
• Check for leaks: Opens in new tabCheck for any external leaks, as an external leak can introduce air into the system. 

This video demonstrates the process of bleeding air from the power steering system: 57sCARDONE IndustriesYouTube · Nov 21, 2014
Important Considerations

• Safety: Always use jack stands to support the vehicle, never relying solely on a jack. 
• Fluid type: Use the correct type of power steering fluid specified in your vehicle’s owner’s manual to avoid damage. 
• Do not overfill: Overfilling the reservoir can cause fluid to spew out. 
• Avoid holding the wheel at stops: Turning the wheel to the full lock position for extended periods can put excessive strain on the power steering system. 

How to get air out of power steering without a vacuum pump?

You remove the lid of the fluid reservoir, top up the fluid, and turn the steering wheel from lock to lock a few times. This should remove the air from the system. The you top up the fluid again – if it needs it, and repeat the process until it doesn’t.