2001 Subaru Steering rack

I took my 2001 subaru in for a head gasket and timing belt repair - during this repair they changed the power steering fluid, along with oil. After leaving the shop, i noticed a hummimg sound and also started to feel the car vibrate or studder when i turned left or right. I immediatley called the shop and they stated this happens sometimes when power steering fluid is changed and air gets in the lines. They thought they had bled it out enought but obviously it didn’t work. They said this should clear up, but when i got home to turn the car to the left and right really hard, let it sit an hour…then come out and turn the car on and off and do that again. WELL - that didn’t work, i gave it another two days - still nothing. I took it back, they changed the fluid again, did say they saw air in it and said i should be good. WELL - again its not fixed. SO i take it back and now they tell me i need they found a leak in my steering rack and i need another $600’s worth of work. NOW my question is - could this have been something they should have caught, and / or is this something that they could have created. They did admit having put the power steering pump on its side that would have created the air in it, but that what they did was not near where this leak is. BUT i did ask them several times when i called each time to let them know i was still having this issue - could me driving this car create further damage and they said no. Could me continuing to drive it with this sound also create the leak? I did not have any issue prior to taking the car in with my steering. Yes its an older car and i get that things can go mechanicaly wrong but just seems to coincedental. HELP

If they moved the power steering pump to get to the head*, it flexed the lines some. Look at the steering pump and inspect the lines coming out of it. One end has a rubber hose with two hose clamps on each end. It is entirely possible that steering fluid is leaking out of that junction.
IF that’s it and they maintain you need a new rack, they are being quite dishonest because a Subaru mechanic would know to look there first. If the leak is caused by the connections that the little piece of hose makes, it may just need to be clamped down properly or maybe it needs to be replaced. Something really cheap and likely something they caused.

Also, is the steering belt tight? If it isn’t tight, you would feel a vibration and stutter while turning. Usually you’d hear a noise too. They must have loosened the belt to get the steering pump out of the way so maybe it just needs tightening.

*On a Subaru, you unbolt and flip the steering pump over to the wheel well area when you need elbow room.

Thanks RemcoW - that helps me alot - just getting ready to call them back. They did check the belts and those appeared tight.