steering is very heavy at no/low speed. little better at normal driving speeds

[Fast4esT]

steering wheel is annoying heavy to turn when stopped or parking/low speeds. It gets noticeably better but still not normal above 30mph. The wheel returns almost back to center by itself when driving at normal highway speeds but needs help the last couple degrees. It feels like the power steering pump works so im not sure if its the problem.

I also had a slow PS fluid leak which im pretty sure I fixed, fluid never would get low low but just low enough for the pump to make noise, I always added fluid immediately if I heard any noise and it would only take small amount of fluid added to be full. one bottle of fluid lasted 2 years, so slow-ish leak.
anyway

I replaced the high presser pump to rack line and installed a s4 rack hoping that the steering would improve but it is still the same, no better, no worse.

it always feels a little bit notchy like there is a dead spot where I turn the wheel 20ish degrees either direction at normal highway speeds.

I don't wanna keep throwing parts at it but most the hoes left to change are pretty cheap. I just don't know how to diagnose it further

I did bleed the system by turning the wheel after changing the rack and hose.

[Kevin C]

You do know that the the S4 rack is a servotronic rack that will feel heavy without the electronics hooked up? You may have have other issues but that one wont help.

[Fast4esT]

Yes but I had this problem before installing the rack, it is heavy like there is almost no power assist, 2 hands to turn the wheel. Takes a lot of joy out of driving the car

[EuroxS4]

Check pump or lines for metal. IIRC there is a pressure check valve in one of the hoses, make sure pressure is being produced by pump.

[Mike Tries]

Tell us about the last known proper operation of the steering. Did you hit something? A pothole, or a big bump, or... gently kiss a curb in the snow while turning into a parking lot at 3 mph and destroy the wheel, control arm, and subframe, all from a 3 mph impact? And then have the winch on the tow truck break, allowing the car to slide off the back of the truck, colliding with your neighbor's fence and having the steel support cable from a utility pole cut the trunk in half as it hurled through it?

[Fast4esT]

no no no, never had done any damage. it seemed to just gradually become a problem over time.
I will check for metal in the lines and check out the check valve, that sounds like something to investigate. do you know by chance what hose it is in? I assume its one of the two hoses that are also metal tubing,

I can see the fluid moving in the reservoir when turning wheel back and forth

[Turbo510]

My steering got heavier after changing the steering rack with an OEM-rebuilt. I'm used to it, but my wife bitches about the A4's steering, especially after driving her Q5. I assume that the rack's assist action is dependent on springs in the pinion's valve body.

[Kevin C]

My steering got heavier after changing the steering rack with an OEM-rebuilt. I'm used to it, but my wife bitches about the A4's steering, especially after driving her Q5. I assume that the rack's assist action is dependent on springs in the pinion's valve body.

Exactly. The A4 is bit heavy feeling compared to the units (cars) with servotronic and servotronic is heavier disconnected. My experience is if you have a lot of friction in a steering joint you will get a stick slip juddering as it fails. My tie rods did that...Ball joints did as well, but not as easy to hear. Either Way the OP should be able to tell when moving the suspension with the wheels in the air. I would be looking at EuroxS4 posted, poor pump performance, or a problem with a line. The correct way is to get a pressure gauge on the line. Easy it to drop a used pump in and see if it works.

[shurur9]

Check valve is probably were the restrictor-reducer is in the non-servotronic system: the line that feeds (supply) into the reservoir.

[Fast4esT]

I think there is a valve in the high pressure line, also I think a valve in the pump. I haven’t come across any posts about replacing the valve in the pump only the pump itself.
Control arms and tie rods are all fresh as well before the rack was installed and did not chang anything
Steering feels the same after racking stall as before.
I had a urs6 with servo disconnected and that steering still had more power than what I currently have, I can’t imagine that a s4 rack is going to be so heavy you almost have to lean into it to turn. I do have access to a b6 s4 I can unplug the servotronic and see how heavy the wheel becomes. What I remember on my urs6 was the steering feel became more comfortable and slightly heavier

[Fast4esT]

I’ll check if there’s anything attached to this line

Check valve is probably were the restrictor-reducer is in the non-servotronic system: the line that feeds (supply) into the reservoir.