Nissens 999238 A/C Expansion Valve

Nissens A/C Expansion Valve for Mercedes-Benz

Nissens part number 999238 is an aluminum block-style A/C expansion valve for R134A systems. It is built for Mercedes-Benz HVAC applications where precise refrigerant metering is needed to support stable evaporator performance and consistent cabin cooling.

• Aluminum block construction for HVAC service applications
• Designed for R134A refrigerant systems
• Block-style expansion valve configuration
• Mounting hardware included
• O-rings included; 4 O-rings listed
• Liquid inlet thread diameter: 0.4300
• Liquid outlet thread diameter: 0.5500
• Suction inlet thread diameter: 0.6300
• Suction outlet thread diameter: 0.7900

Fitment and Application

This A/C expansion valve is listed for Mercedes-Benz models including CLK320, CLK430, CLK55 AMG, E320, E430, E55 AMG, SL500, C230, C280, C43 AMG, SLK230, S320, E300, C36 AMG, E420, and C220 across the 1994-2003 model years. Fits 1998-2003 Mercedes-Benz CLK320, N/A. Fits 1999-2003 Mercedes-Benz CLK430, N/A. Fits 1996-2003 Mercedes-Benz E320, N/A. Fits 2001-2002 Mercedes-Benz CLK55 AMG, N/A. Fits 1998-2002 Mercedes-Benz E430, N/A. Fits 1999-2002 Mercedes-Benz E55 AMG, N/A. Fits 1999-2002 Mercedes-Benz SL500, N/A. Fits 1997-2000 Mercedes-Benz C230, N/A. Fits 1994-2000 Mercedes-Benz C280, N/A. Fits 1998-2000 Mercedes-Benz C43 AMG, N/A. Fits 1998-2000 Mercedes-Benz SLK230, N/A. Fits 1997-1999 Mercedes-Benz S320, N/A. Fits 1995-1998 Mercedes-Benz E300, N/A. Fits 1995-1997 Mercedes-Benz C36 AMG, N/A. Fits 1997 Mercedes-Benz E420, N/A. Fits 1994-1996 Mercedes-Benz C220, N/A.

This part cross-references Four Seasons 39210 for the same application.

What It Helps Address

• Weak or uneven cabin cooling
• Incorrect refrigerant flow through the evaporator
• HVAC performance issues tied to a worn expansion valve
• Temperature fluctuations in Mercedes-Benz A/C systems
• Service replacement needs during A/C repair

Installation Notes and Tips

Verify refrigerant type, port dimensions, and system layout before installation. This valve is listed for multiple Mercedes-Benz HVAC configurations, including various E-Class and C-Class applications, so confirm the original part style and connection sizes against the vehicle before service. Replace the O-rings during installation and inspect the surrounding A/C components for contamination or wear.

Quality Assurance

Nissens develops and manufactures thermal management components to a high production standard, with product development aligned to changing aftermarket and vehicle technology requirements. Part number 999238 reflects that focus on OE-style HVAC service parts for Mercedes-Benz A/C repair.