I have a 2004 Toyota Avalon. Had all the belts changed about a month ago because they squealed whenever it rained. Now my power steering is acting up. Seems like there is little boost at slow speed, but gets a little better as the engine warms ups. PS fluid level is OK and within range. Any suggestions?
Check the belt tension. Maybe the belt is loose.
You say little assist at slow speed but better when warmed up. By warmed up do you mean at higher speeds, or is it better when warmed up at slow speeds as well? Is the assist uneven? You didn’t mention an external leak or unusual noise so it’s probably a belt issue or an issue inside the rack.