How do I get air out of Power Steering System?

[toms68cst]

I've got one little headache to take care of before I can drive my truck.

I had the PS hoses apart from the pump while I had my engine out. I've got everything back together but I can't get it to work correctly. I've refilled the fluid and tried to work the steering wheel back and forth several times with the engine running. It just makes loud groaning/hissing noises and only boosts a little bit once and a while turning in one direction. The fluid turns all throthy and usually overflows the PS pump.

It's the usual PS steering gear found on 69 and later trucks not the 67-68 booster style of PS.

Are there any tricks? I've done this a couple of times in the past and I've never had any problems working the air out.

Thanks, Tom