Some 2024-2026 Mazda CX-90 and 2025-2026 CX-70 vehicles may exhibit green residue on the outer surface of the coolant reserve tank, which appears to be coolant blowback. This is caused by coolant seeping out and appearing as leakage from small pores (slight gaps) formed due to the deterioration of the tank material. The eliminate this concern, the material of the coolant reserve tank has been modified. Replace the tank with P/N PX28-15-351B. Also replace the radiator drain cock gasket with P/N PX28-15-204.