HMMWV Humvee Coolant Surge Tank 12340061 | NSN 2930-01-256-5350

Restore your cooling system’s reliability with an OEM-spec Military HMMWV Humvee Coolant Surge Tank (NSN 2930-01-256-5350). Engineered to handle extreme temperatures and heavy duty operations, this direct-replacement coolant expansion bottle ensures proper engine pressure regulation and prevents critical overheating. Over time, original factory composite tanks suffer from chemical degradation due to old coolant, micro-fracturing under high-pressure cycles, and neck warping that ruins the radiator cap seal. If you notice a persistent drop in coolant level without a visible puddle, intermittent low-coolant lights, or white crusty residue around the seams, it is time for a replacement before a major hose blow-out occurs. Cross-Reference & Part Numbers To ensure perfect fitment, this military-grade surge tank replaces and interchanges with the following part numbers: National Stock Number (NSN): 2930-01-256-5350, 2930PL0703685 Military / AM General Part Numbers: 12340061, 12340062, 5596079 Civilian Hummer H1 Part Numbers: 5744154 Vehicle Compatibility & Model Numbers This coolant surge tank is compatible with 6.2L and 6.5L naturally aspirated and turbo diesel variants across the entire military M-series fleet. Fits models: M998, M998A1, M1025, M1025A1, M1025A2, M1026, M1026A1, M1035, M1035A1, M1035A2, M1037, M1038, M1038A1, M1042, M1043, M1043A1, M1044, M1044A1, M1045, M1045A1, M1046, M1046A1, M1069, M1097, M1097A1, M1097A2, M1113, M1114, M1121, M1123, M1145, M1151, M1151A1, M1152, M1152A1, M1165, M1165A1, M1167