Power steering fluid foaming

The other day I left my truck on in park for almost an hour. When I started driving again the pump was noisy and the fluid was foaming. I left it overnight and it was completely fine the next day. Drive it around maybe 30 miles and nothing happened until I hit a small dip in the road and then it was noisy again and started foaming. Same thing this morning, completely fine but I’m sure if I drive it long enough it’ll start foaming again. Fluid is new, just flushed it recently and bled the air out maybe 3 weeks ago. Level was halfway to the cold mark so I topped it off but other than that I’m not sure what to check. I looked around for any signs of leaks but couldn’t find any. Should I try bleeding again?

 

You must have a leaky return line. Pulling in air and causing the pump cavitate and make that whiny noise.

 

Which one is the return line?

 

This.

Air is being sucked in.

 

I don't know exactly. Id start by looking for oil seepage.

 

The rack has been leaking very slowly through the inner tie rod boot for about a year now but never caused me any issue. I’m guessing this is probably where the air is getting in at?

 

Have you bled your system at all after repairing/replacing anything steering related?

On my Land Cruiser, I had rebuilt the power steering pump along with replacing my low pressure and high pressure lines.

Did a quick bleed and test drive only to have it cavitate so I propped the front up, pulled the cap, and did a lot of lock-to-lock turning on my steering and topped off as needed.

No more foam, no more whining, and my power steering was back to feeling like new.

 

Riley0226

Return hose either #9 or #10
says 4wd “serviced w/pressure tube”
That is what is confusing

 

So look at the ends of #8 and one end of #9…..they bolt into a connector (pump/hard line from rack)

All 3 of those connectors have small O-ring that fails (leaking or sucking in air to system and making that foam u saw)

this is common problem for Honda/Acura
But awesome news to fix….one 10mm bolt and a $5 oring(s)
GL