Four Seasons 3121NK A/C Compressor and Component Kit

Complete A/C Kit for LeSabre and Bonneville

Four Seasons 3121NK is a complete air conditioning kit with a new compressor for select Buick LeSabre and Pontiac Bonneville applications. It combines the major A/C service components needed for an R134a system refresh, including the compressor, accumulator, orifice tube, PAG oil, and O-rings.

The Four Seasons Complete A/C Kit line is built for direct-fit HVAC service, giving you the core parts needed to restore system operation on vehicles equipped with a V5 compressor. This kit is a practical choice when servicing a Buick LeSabre or Pontiac Bonneville A/C system that uses an orifice tube expansion device.

Key Features

• Four Seasons 3121NK complete A/C compressor kit
• Includes a new compressor, accumulator, orifice tube, PAG oil, and O-rings
• Uses PAG Oil /150 and R134a refrigerant
• Orifice tube style: standard, yellow, .062 in. diameter
• Accumulator with P-nut inlet and outlet fittings
• Gaskets and seals included
• Limited lifetime warranty
• Cross-references Monroe Shocks & Struts 172286 and 182286 for the same application

Detailed Description

Four Seasons 3121NK is a complete air conditioning kit for 2000-2005 Buick LeSabre and 2000-2005 Pontiac Bonneville models listed with a V5 compressor. It is built around a new compressor and includes the matching accumulator, orifice tube, PAG oil, and O-rings to support a full A/C system repair. The kit is configured for R134a refrigerant systems and uses an orifice tube expansion device, making it a direct match for the specified vehicle applications.

This part number, 3121NK, is also referenced by interchange numbers 520565 and MK1020. For buyers searching for a Buick LeSabre A/C compressor kit or a Pontiac Bonneville complete air conditioning kit, this package brings the major service components together in one application-specific solution.

What It Helps Address

• Weak or non-functioning cabin cooling
• Compressor noise or compressor failure
• Low refrigerant system performance after component wear
• Accumulator-related moisture control issues
• Orifice tube restriction or metering problems

Installation Notes and Tips

Verify the vehicle uses the listed V5 compressor configuration before ordering. Confirm refrigerant type, accumulator fitting style, and orifice tube specification against the original system. Replace the receiver drier/accumulator and related seals during service, and follow the correct PAG oil charge procedure for the system.

Fits 2000-2005 Buick LeSabre, N/A. Fits 2004-2005 Pontiac Bonneville, N/A. Fits 2000-2003 Pontiac Bonneville, N/A.

Quality Assurance

Four Seasons 3121NK carries a limited lifetime warranty. The kit is built as a complete A/C service package for the listed Buick LeSabre and Pontiac Bonneville applications, with the compressor oil included and the required seals provided in the kit.