power steering fluid

just got back from the steelership and the mech said that my power steering fluid is dirty and that it would cost 120 cad to replace it.

now heres the story i went into that same dealership for my oil change 3 months prior to this and the mech did not say anything about changing the power steering fluid at that time. advance to now and all os a sudden my power steering fluid is dirty and i need to change it.

what gives i never had to chage the power steering fluid on any of my cars now at 80 000km on my sienna i need to chage it. something does not add up right.

However i do get power steering pump noise when the fluid is cold up here in canada let say from anywere from 5c and below i can hear my pump pushing the fluid until it get warmed up.