2001 Mazda626 124K m-Steering noise after ALT belt changed

New alternator belt installed by local shop. Now steering pump making noise though never did before this other belt installed. Steering fluid is full, perhaps a tiny, little bit overfilled. Sounds like the pump is cavitating to me though it does not get excessively hot, nor do the feed and supply lines. My tech stated he added some steering fluid " conditioner" after he noticed the noise also. Steering system functions perfectly, the noise occurs most when actually steering the vehicle. Any ideas?