Nissens 999235 A/C Expansion Valve - Front

Nissens A/C Expansion Valve for Mercedes-Benz

The Nissens 999235 A/C expansion valve is a block-style HVAC flow restrictor built from aluminum for R134A refrigerant systems. It is used in rear and front air conditioning circuits on select Mercedes-Benz models, helping regulate refrigerant flow through the evaporator for stable cabin cooling.

• Block-style A/C expansion valve for HVAC refrigerant control
• Aluminum construction for corrosion resistance and thermal stability
• Configured for R134A refrigerant systems
• O-rings included; mounting hardware not included
• Liquid inlet thread diameter: 0.4300
• Liquid outlet thread diameter: 0.5500
• Suction inlet thread diameter: 0.6300
• Suction outlet thread diameter: 0.7100

Detailed Product Information

Nissens part number 999235 is an A/C expansion valve designed for Mercedes-Benz HVAC systems that use a block-type flow control layout. By metering refrigerant into the evaporator, it supports proper pressure balance and consistent cooling performance. This part cross-references Four Seasons 39208 for the same application.

Compatible With Mercedes-Benz C240, C320, C32 AMG, S430, S55 AMG, S600, SLK230, SLK32 AMG, SLK320, and S500 applications across the 2000-2005 model years. Fitment includes rear applications on 2003-2005 Mercedes-Benz C240, C320, and C32 AMG, plus front application coverage on 2003-2004 Mercedes-Benz S600.

What It Helps Address

• Weak or inconsistent cabin cooling
• Incorrect refrigerant metering at the evaporator
• High-side or low-side pressure irregularities related to valve restriction
• A/C performance loss after HVAC service or component replacement
• Refrigerant flow issues in rear or front climate control circuits

Installation Notes

Verify refrigerant type, port dimensions, and vehicle-specific fitment before installation. Replace the O-rings during service and inspect the surrounding A/C lines, seals, and evaporator connections for wear or contamination. Proper evacuation and recharge procedures are required after installation.

Quality Assurance

Nissens develops and manufactures thermal management components to consistent quality standards across its aftermarket range. Part number 999235 is built as a direct-fit replacement for the listed Mercedes-Benz applications and is supported by Nissens' product engineering focus for HVAC systems.