I have a 2005 SR5 with 150,000 miles. My AC compressor went out after 12 years. Mechanic tested the old one with dye and found leak at Compressor. After replacing compressor I have good AC again.
Amazon.com: Denso 471-1413 New Compressor with Clutch: Automotive
Amazon sells a Denso for $200. I bought it for him and he charged $200 to install, evac the system and recharge.
Don't try this yourself. You need special equipment.
DENSO IS THE OE SUPPLIER FOR THIS VEHICLE, w/NEW COMPRESSOR, OE-SPECIFIED O-RINGS AND OIL INCLUDED