Dongfeng KR truck parts Expansion tank assembly 1311010-KS110

Designed to manage coolant volume changes in the engine’s cooling system, the tank features a dual-chamber structure that separates active coolant (for circulation) from overflow coolant (for recovery). The main chamber holds 2.2L of coolant (sufficient for Dongfeng KR’s 6-cylinder diesel engine) and includes a built-in baffle that prevents coolant sloshing during vehicle acceleration or cornering—ensuring consistent coolant supply to the radiator. The overflow chamber (0.6L capacity) collects excess coolant expelled when the system heats up (expansion) and returns it to the main chamber as the engine cools (contraction), reducing coolant loss by 90% compared to tanks without recovery functions. A clear sight glass (marked with “MIN” and “MAX” levels) allows easy visual inspection of coolant volume, eliminating the need for disassembly to check levels—critical for quick maintenance checks during long hauls

Built to withstand the harsh conditions of engine coolant (ethylene glycol-based, pH 8.5–10.5) and temperature fluctuations, the tank uses high-performance materials. The tank body is crafted from food-grade HDPE (High-Density Polyethylene) with UV stabilizers, which resists chemical corrosion from coolant additives, prevents metal ion leaching (which causes radiator clogs), and tolerates continuous operating temperatures from -40°C (cold starts) to 120°C (system heat peaks) without warping or cracking. The internal components—including the pressure relief valve seat and baffle—are made of glass-fiber-reinforced PP (polypropylene) for added rigidity, while the external mounting brackets are zinc-plated steel (Q235 grade) that resists rust from road salt or moisture. Unlike metal tanks that corrode or low-grade plastic tanks that degrade, this material combination ensures the tank operates reliably for 5+ years

At the core of the assembly is a factory-calibrated pressure relief valve that maintains the cooling system’s optimal pressure (140kPa ±5kPa)—critical for raising the coolant’s boiling point (up to 126°C) and improving heat transfer efficiency. The valve automatically opens when pressure exceeds the rated limit, releasing excess coolant into the overflow chamber to prevent radiator or hose damage. When system pressure drops (as the engine cools), the valve closes to maintain a sealed system, preventing air ingress (which causes cavitation and overheating). The valve features a silicone seal (70 Shore A hardness) that resists coolant degradation and ensures airtight sealing, even after 10,000+ pressure cycles. Unlike aftermarket tanks with generic valves that miscalibrate easily, this OEM valve is pre-tested to match Dongfeng KR’s cooling system specs, eliminating risks of overpressure or underpressure failures

Designed for hassle-free replacement by fleet technicians or DIY owners, the assembly simplifies installation and upkeep. It includes all necessary hardware: 4 stainless steel mounting bolts (M6×20mm), lock washers, and 2 OEM-spec coolant hose clamps (for inlet/outlet connections). Installation takes 20–25 minutes: align the tank with the engine bay brackets, secure the bolts to 20 N·m torque, connect the coolant hoses to the quick-connect ports, and tighten the clamps. For maintenance, the tank’s smooth HDPE surface is easy to clean with a damp cloth (resisting coolant stains), and the sight glass is scratch-resistant for long-term visibility. The pressure relief valve is serviceable (via a removable cap) for cleaning or replacement, while the overflow pipe has a built-in filter that prevents debris from entering the tank. Each unit undergoes pressure testing (160kPa for 30 minutes), leak testing (submersion in water), and material compatibility checks, backed by a 24-month warranty against defects (e.g., tank cracking, valve failure, hose connection leaks)