Persistent Air in Power Steering System After Flush/Rack Change, First Gen, 3.4L

Hello All,

A week or so ago, I replaced the steering rack on my '99 Tacoma. In preparation for that, I flushed the power steering system, removing the fluid reservoir in order to clean out the reservoir and filter screen. After replacing the rack, I went through the bleeding process.

However, I find the pump continues to whine, and I find I still have air in it ( visible froth and bubbles ). In addition, I now have a PS fluid leak that seems to be in the pump area.

I did not replace the O-ring that seals the connection between the reservoir and the pump during the flushing process, and my working theory is that this O-ring is leaking - either because it was damaged during replacement of the reservoir onto the pump or because it has hardened and once removed, it will no longer seal properly. My thought is that air is being sucked into the system around that O-ring, along with fluid from the reservoir. I hypothesize this is also my PS fluid leak, when the engine is not running.

I've not read of anyone else finding that air is being pulled into the system around this O-ring. I HAVE read posts suggesting air is entering through a leak in the return line. That does not make sense to me however, since that line would be positively pressured.

Any thoughts, experience or insights shared, would be greatly appreciated.

 

I would replace the o ring and see if it fixes the problem. If not, then check for other things.

 

That's the plan