Four Seasons 5681NK A/C Compressor and Component Kit - Front and Rear

Complete A/C Kit for GM Van Applications

Restore cabin cooling with the Four Seasons Complete A/C Kit 5681NK. This kit combines a new compressor with matched air conditioning service components for R134a systems, making it a direct-fit solution for select Chevrolet G10, G20, G30 and GMC G1500, G2500, G3500 vans with LTR4 compressor setups.

Built around the Four Seasons Complete A/C Kit line, this package is organized for full-system service on front and rear HVAC configurations. It includes PAG 150 compressor oil, an orifice tube, an expansion valve, an accumulator, and O-rings to support a complete A/C compressor replacement on the listed GM van applications.

Key Features

• Four Seasons 5681NK complete A/C compressor kit
• Includes a new compressor, accumulator, orifice tube, expansion valve, PAG oil, and O-rings
• Uses PAG Oil /150 for R134a refrigerant systems
• Orifice tube specification: 0.072 in. diameter, white, standard style
• Accumulator dimensions: 3.500 in. diameter and 9.000 in. length
• Accumulator fittings: 0.750 in. inlet and outlet, female O-ring inlet, male insert O-ring outlet
• Limited Lifetime warranty

Product Details

The Four Seasons 5681NK is a complete air conditioning kit with a new compressor for vehicles using an LTR4 compressor configuration. It is built for R134a refrigerant service and includes the core replacement parts needed when servicing a worn or failed A/C compressor system. For Chevrolet G10, G20, and G30 as well as GMC G1500, G2500, and G3500 vans, this kit supports front and rear HVAC layouts listed in the fitment data.

This part cross-references Four Seasons 5681NK for the same application.

What It Helps Address

• Loss of cooling performance from a failing compressor
• Noisy or seized compressor operation
• Restricted refrigerant flow from a worn or incorrect orifice tube
• Moisture or contamination concerns in the accumulator and related A/C components
• System service needs after compressor replacement on R134a vehicles

Installation Notes and Tips

• Verify the vehicle uses an LTR4 compressor before ordering or installation.
• Confirm the compressor pulley configuration matches the application notes, including 6-groove pulley coverage where listed.
• Flush the system as needed and replace the accumulator, orifice tube, expansion valve, and O-rings during service.
• Use the specified PAG 150 oil amount and refrigerant type for the vehicle system.
• Evacuate and leak-check the system before charging.

Quality Assurance

Four Seasons backs this kit with a Limited Lifetime warranty. The matched component layout helps support a complete A/C repair on the listed Chevrolet and GMC van applications, including 1987-1991 Chevrolet G10, G20, and G30 and 1987-1991 GMC G1500, G2500, and G3500 models.