What Causes Severe Bubbling in the Power Steering Pump Reservoir?

[RoseFitz]

The reason for bubbling in the power steering pump reservoir may be due to excessive oil level, high oil surface, or a clogged oil inlet filter screen, causing oil to churn when returning during steering. Function and characteristics of power steering fluid: Function: Power steering fluid is a medium oil added to the power steering system, serving to transmit steering force and provide cushioning. Characteristics: Power steering fluid, also known as power steering oil, is essentially a type of hydraulic oil. Compared to brake fluid, it has higher viscosity, poorer fluidity, and can corrode the sealing components of the brake system. Method for replacing power steering fluid: Before replacing the power steering fluid, start the car and use an oil extractor to remove all the old fluid, then inject new power steering fluid. Next, turn the steering wheel back and forth to allow the new fluid to permeate, which also helps clean the system. For thorough permeation, it is best to turn the steering wheel sharply left and right first, then make slight left and right turns. However, the purpose of turning the steering wheel back and forth is to expel the old fluid from the steering gear. Avoid holding the steering wheel at full lock for extended periods, as this can cause excessive oil pressure and lead to fluid ejection. Repeat this process three times to ensure all old fluid is completely removed before adding new fluid. Note that the same type of power steering fluid should be used for all three additions, and mixing different types is not allowed.

[VonNaomi]

A few days ago, my old car also had the issue of bubbling in the power steering pump reservoir, and it took me quite a while to figure it out. This usually happens when air gets into the steering system, possibly because the reservoir cap wasn’t tightened properly or the sealing ring has aged and is leaking. When driving, the steering wheel becomes extremely heavy, and the power assist feels intermittent—super dangerous. I was in too much of a hurry and didn’t check the fluid level initially, but later found out it was too low. Adding some power steering fluid fixed it. Sometimes, it’s also caused by the car running at high speeds for too long, overheating the fluid and creating bubbles. If you encounter this, I recommend stopping immediately to check the reservoir fluid level, and if that doesn’t help, take it to a mechanic. Don’t delay, or the power steering pump could fail, costing you a fortune in repairs—like the time I wasted over a thousand bucks. Also, make it a habit to check your fluids regularly to avoid getting stranded on the road.

[SanElijah]

As someone who frequently repairs cars, I notice that bubbles in the power steering pump reservoir usually indicate air entering the system, often due to poor sealing of the reservoir cap or hoses causing air leaks. Vigorous bubbling in the reservoir means the pump is drawing in air while sucking fluid, which can lead to power steering failure and make the steering wheel harder to turn. Additionally, low fluid levels, aged fluid, or contamination can also increase bubble formation. Over time, this can cause wear on the pump vanes, requiring part replacement. For troubleshooting, first turn off the engine and check the fluid level in the reservoir, topping it up to the correct mark. If bubbles persist, inspect all hose connections and the reservoir's seal. I've seen cases where using low-quality steering fluid with incorrect viscosity caused boiling and bubbling. Switching to OEM fluid can help resolve the issue.

[OClaire]

I also encountered the issue of the power steering fluid reservoir bubbling when I didn't know much about cars. Now I've learned a few tips to deal with it. First, pay attention to the fluid condition: check if the fluid level is too low or has turned whitish, which requires topping up. The cap might not be tight enough, so try screwing it firmly. Avoid jerking the steering wheel while driving, as this increases system pressure and creates bubbles. If bubbles still appear after parking, check for oil leakage traces. If the fluid level is normal but bubbles persist, it could be due to excessively high oil temperature or poor oil quality, requiring an oil change. Don't attempt disassembly yourself; if simple checks don't resolve it, visit a professional shop to inspect the power steering pump and the entire system to avoid risks.