We’ve had a few customers mention this with their new Tacomas, especially in humid areas from the Bay Area or after the vehicle’s been sitting overnight or for days at a time without driving. It’s a fairly common thing we’re seeing across Toyota’s newer platforms in general.
Typically, it’s just surface moisture or light rust buildup on the rotors causing the pads to squeal when reversing cold. It’s more noticeable in reverse because of the angle and light brake pressure. Driving more and letting the pads fully break in usually helps as the pads seat better and wear evenly, and the noise tends to fade over time.
