Usually on replacing and refilling the powersteering fluid, it takes a fair bit of lock to lock turning to bleed it...
Best way I found was to jack up and use axle stands the front end of the car to make it a lot easier on the steering, tyres and suspension...
Double check your manual for total fluid capacity... You'd be surprised at how much it uses and if you top it up and it runs low while bleeding, it's back to square one again.
Double check ALL the joints, pump, rack and pipes for loose connections, splits etc. Anywhere air can be drawn back in.
Start the engine.
Make sure that the cap on the reservior is removed and you have a helper constantly topping up
Turn lock to lock and hold it on full lock for 3 seconds at a time, the noise will change. It usually takes a minimum of twenty to twenty five turns to bleed it assuming you have no other leaks.
Failing that, remove the clips that hold the steering rack gaitors to the inner rack and check to see if any fresh fluid is pushing past the rack seals themselves, it should be easy to see on some kitchen towling once you wipe the metal rods, it will be a nice red colour if all is not well with the seals.
IIRC its around 2.1 litres on a 156 of DEXIII from empty to fully bled... so if you are using anymore than that while bleeding on a 147 , then you have a definate leak still
Good luck mate HTH
Ps... make sure that the little rubber pipe that attaches to the power steering filler cap is breathing ok, no blockages to prevent further pressure variance.