My car keeps running out of power steering fluid. So after filling it back up with power steering fluid again, I left the car running and watched under the hood. The cap popped off and all of the fluid just came bubbling back out of it.

What is this and how can I fix it? I can't steer at all hardly and it won't hold the fluid long enough to get in to the system or hoses.

1 Answer 1


The bubbling up is due to air in the system. You have a leak of some kind:

  1. Fluid leak: if you have a leak and the system runs very low air will get into the places the fluid should be, when you add fluid back in it displaces air. When you refill it you need to turn the wheel back and forth all the way a few times to bleed the air out of the system. You fill it, exercise the wheel a few times, refill to the full level, then do it again until all the air is worked out, you have no bubbles and the level stays constant
  2. Air leak: A leak could be allowing air to be sucked into the system, which is a bad thing

I would try the procedure in 1. and see if it works. If the bubbling stops and the cap stays on then you may be able to live with it awhile. Monitor the fluid loss, if it's slow you may be able to leave it for a bit, if it's fast you need to get it taken care of. If you follow the process to bleed the air out and it still bubbles up and the cap comes off then you're going to need a repair. Leaving that would be dangerous.

Note: best practice is to have the front wheels off the ground when you bleed the air from the system, this is because the load on the system is highest when the car is stopped and weight on the wheels. If you can raise the front of your car car up safely it's worth the effort. If you can't do that but you do have an open area you can drive around then you can reduce the load on the system by driving around slowly while you turn the wheel all the way back and forth. It's kinder on your tires as well.

  • 1
    It's usually recommended when you try to bleed the power steering system to have the front wheels off the ground so there's little to no "power" from the power steering needed to operate it. It's also called "dry steering", which wears out your tires in one spot. Mar 11, 2022 at 10:33
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    That is true @Pᴀᴜʟsᴛᴇʀ2, I'm working on the assumption that the poster isn't in a position to do that, but I'll edit that in.
    – GdD
    Mar 11, 2022 at 10:55

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