06 xc70 pulsing power steering

[BryonTheCanadian]

My New to me is great but a few quirks id like to tackle, this forum is fantastic i must say great thanks to everyone. My steering into a tight fast corner like a on ramp that produces some steering pack pressure creates a steering pulse feed back to the wheel. Its like your on some ice and tires have a tine slip. Feels like the power steering is loosing pressure for a split second. Does not feel like a cv joint. I've never experienced it before exactly. The previous owner suggested it was always there and he go use to it for the last 6 yrs. .. Any ideas or suggestions would be appreciated many thanx

[oragex]

This may be a little trickier, do you feel the 'on/off' assist while the steering is at an angle but stationary, or while actually rotating it ?

It this at full lock ?

[jimmy57]

The problem is not really clear but alignment is on the list for odd feeling in steering on corners. Also the rear bushing on front lower control arms. There were issues with P/S reservoir allowing air ingestion into fluid on earlier year P2 models but it usually was noted by the growling noise from pump but could be pusling steering due to the air in fluid. You wouldn't have the pulsing without also having noisy pump if it was air. Volvo p/s pumps really want Pentosin or Volvo fluid so red atf being in it might cause you some odd issues with feel too.

[EngineeringBloke]

In 2012, I had roughness in my 06 S60 power steering. I recall a notchy feeling when I turned the wheel, and that went away after I replaced the fluid with new Pentosin PS fluid.

I disconnected the PS return hose at the PS reservoir and extended it with a length of hose to a bucket. I ran the engine to pump the old fluid out, refilling the reservoir with new fluid continuously to avoid the pump running dry and overheating. After seeing new fluid coming out of the drain hose after a loop through the whole system, I replaced the return hose, checked the level and was done. I was very pleased with the result.