Four Seasons 26778 A/C System Valve Core and Cap Kit

Four Seasons AC System Seal Kit 26778

Restore service access and sealing at the A/C system ports with the Four Seasons AC System Seal Kit, part number 26778. This cap and valve A/C system seal kit is built for R12 and R134a refrigerant applications and is a direct-fit service solution for a wide range of Cadillac, Buick, Chevrolet, GMC, Pontiac, and Oldsmobile vehicles.

Four Seasons AC System Seal Kit 26778 is part of the AC System Seal Kit line, focused on replacement caps and valve core service components for HVAC hose and pipe connections. The aluminum construction and plastic caps with red and blue color coding support straightforward identification during A/C maintenance on GM platforms.

Key Features

• Part number 26778 cap and valve core A/C system seal kit
• Compatible with R12 and R134a refrigerant systems
• Cap & valve kit style for A/C service ports
• Aluminum construction with plastic caps
• Red and blue cap colors for easier port identification
• Direct replacement for select GM HVAC hose and pipe applications

Detailed Description

This Four Seasons A/C system valve core and cap kit is designed for vehicles that use Aeroquip fittings and require service-port sealing components. It is a practical replacement for worn, damaged, or missing A/C caps and valve cores on many Cadillac CTS, Chevrolet Silverado 1500, and GMC Sierra 1500 applications, as well as numerous Buick, Pontiac, and Oldsmobile models. The part number 26778 also cross-references Global Parts Distributors LLC 1311568 for the same application.

Use this kit when you need to maintain refrigerant system sealing at the service ports, preserve access for future A/C service, and keep the HVAC system organized with clearly identified caps. Compatible vehicle coverage spans model years from 1994 through 2008 across a broad range of GM cars, trucks, SUVs, and vans.

What It Is Used For

• Replacing cracked, missing, or damaged A/C service port caps
• Restoring valve core sealing at refrigerant service points
• Addressing slow refrigerant loss at service connections
• Cleaning up A/C maintenance on R12 and R134a systems
• Servicing GM HVAC hose and pipe connections with Aeroquip fittings

Installation Notes and Tips

• Verify refrigerant type and service-port style before installation.
• Inspect the valve core area and surrounding fitting for wear or contamination.
• Confirm fitment by year, make, and model before ordering; examples include Fits 2003-2008 Cadillac CTS, N/A; Fits 1999-2005 Chevrolet Silverado 1500, N/A; Fits 1999-2005 GMC Sierra 1500, N/A.
• Use proper A/C service procedures when opening or closing refrigerant connections.

Quality Assurance

Four Seasons is a recognized aftermarket brand for HVAC service parts, and this seal kit is built to match the listed refrigerant and fitment requirements for the specified applications. Part number 26778 is listed with confirmed interchange references and broad GM coverage for accurate replacement selection.