Volvo Forums - Volvo Enthusiasts Forum - 740 Power Steering

Here's the problem. I have a 1988, 740gl. The power steering is not what it should be. In the mornings when first started there's almost no power steering effect. After 3 or 4 minutes, or if I rev to get about 2000 to 3000 rpm I can get good power assist. when on the run the steering is okay - not brilliant - but okay, however, I noitice an intermittent 'hard spot' when doing a right turn, if I push through this, then it seems to rectify itself. Once turned through the hard spot a couple of times it goes away. My initial thoughts were pump not giving enough pressure for the morning problem and then siezing knuckle for the hard spot... So, changed the pump... no effect. flushed the system, okay for a while, but then started coming back again. Checked the knuckle and lubricated with 'extra penetrating' lubricant/grease... no flat spots or siezure spots. Is it just time to buy a wholke new rack? or in my mind there's probably a load of crud sitting in the bottom of the rack that once the pressure gets up, is then free-flowing in the fluid, but occasionally gets trapped in the bends and twists of the rack. Is there a sure-fire way of TOTALLY flushing the entire system? or is there a way to increas pump pressure. My thougts were to place a smaller flywheel on the pump, which would increase speed of pump and therefore pressure... similar to what happens when I'm at 3000 rpm, which is where pump perfoms 'okay' .... any thoughts, greatly appreciated... !!!