Nissens 999378 A/C Expansion Valve - Front

Reliable A/C Expansion Valve for BMW Models

The Nissens A/C Expansion Valve 999378 is engineered to regulate refrigerant flow precisely in BMW vehicles equipped with R134a refrigerant. Designed with durable aluminum construction, this block-type valve ensures consistent performance for various BMW 5, 6, and 7 Series models.

• Constructed from lightweight, corrosion-resistant aluminum
• Compatible with R134a refrigerant systems
• Block-type A/C expansion valve design
• Includes 4 O-rings for secure sealing
• Liquid inlet and outlet fitting thread diameter: 0.5500 inches
• Suction inlet fitting thread diameter: 0.7900 inches
• Suction outlet fitting thread diameter: 0.7100 inches

Technical Details and Compatibility

The Nissens 999378 A/C expansion valve is specifically designed for BMW models such as the 528i, 535i, 550i, 640i, 650i, 740i, 750i, 760Li, M5, and M6 series, including xDrive and Gran Coupe variants. Its aluminum material offers durability and resistance to corrosion, essential for maintaining optimal refrigerant flow and pressure within the HVAC system. The valve’s block-type design facilitates efficient refrigerant metering, contributing to consistent air conditioning performance.

Applications and Problem Resolution

• Regulates refrigerant flow in BMW R134a A/C systems
• Prevents inconsistent cabin cooling due to faulty expansion valves
• Addresses issues with fluctuating A/C pressure and temperature
• Helps eliminate refrigerant leaks with included O-rings
• Supports restoration of proper HVAC system function in BMW 5, 6, and 7 Series vehicles

Installation Notes and Tips

Ensure the system is fully evacuated and free of contaminants before installing the Nissens 999378 expansion valve. Use the included O-rings to maintain a secure, leak-free seal on all fittings. Verify thread diameters match the vehicle’s specifications: 0.5500 inches for liquid inlet/outlet and 0.7900/0.7100 inches for suction fittings. Professional installation is recommended to maintain system integrity and performance.

Quality Assurance and Warranty

Nissens manufactures this A/C expansion valve to meet OEM standards for fit and function in BMW vehicles. The part number 999378 undergoes rigorous quality control to ensure reliability and durability. While specific warranty details are not provided, Nissens products typically come with manufacturer-backed warranties covering defects in materials and workmanship.