2004 Dodge Ram 2004 Ram 2500 SLT 4x4 diesel w/ power steeri

I suddenly lost my power steering. On inspection of the power steering fluid I found that it was low. I filled it up to the the proper level w/ ATF+4 and did the bleed procedure twice, (jacked up the front end and turned the wheels lock to lock w/ engine off 40 times) It is vastly improved but not quite right. There is no way I can turn the wheels with the truck sitting at idle (800 rpm) but if I just "goose" the throttle up to 1000 - 1100 rpm, the power steering works like a charm. Will bleeding it again help or should I just replace the power steering pump. Also, can a bad brake booster affect the power steering. I assume that a bad power steering pump can affect your brake booster on these diesels but am not sure that it can happen the other way around. My brakes appear to be okay and cannot find any telltale leakage at any hoses on the brake booster, fluid cooler or lines to/ from th pump and steering linkage to account for the initial fluid lose in the pump.
Thanks in advance.
Dave