Buy OEM 2000 Mazda Part # PAF115355 (PAF1-15-355). Engine Coolant Reservoir Cap. 2.5 LITER. CX-30; Expansion Tank Cap. CX-50; Expansion Tank Cap. EXPANSION TANK CAP; Mazda3. JAPAN BUILT

Cap. Reservoir. SUB.
A cover that prevents foreign debris from entering the container. Tank. Engine Coolant. Included with: Reservoir, Reservoir assembly.

Engine Coolant Reservoir Cap

Fits 3, CX-30, CX-50

2.5 LITER. CX-30; Expansion Tank Cap. CX-50; Expansion Tank Cap. EXPANSION TANK CAP; Mazda3. JAPAN BUILT. MEXICO BUILT. W/O 2.5 LITER TURBO.
Engine Coolant Expansion Tank - Repair or Replace
A failed expansion tank can cause the cooling system in your 2000 Mazda to leak antifreeze, or it can cause your engine to overheat. If you're losing coolant, contact our service department to avoid engine damage.