3mirrors Rear A/C Block-Off Kit for 2014–2019 Chevy/GMC/Cadillac SUVs — HNBR Washers & Stainless Hardware

3mirrors Rear AC Block Off Kit is a complete, OEM-style sealing kit that isolates and caps the rear air-conditioning lines on select 2014–2019 Chevrolet, GMC and Cadillac full-size SUVs without modifying the front system.

When the rear HVAC components fail or are removed, refrigerant loss and unnecessary repair costs can follow if the rear lines remain open. This kit provides a straightforward, durable way to cap the rear A/C lines so the front system continues to operate normally. Built-to-fit hardware, corrosion-resistant fasteners and high-performance HNBR sealing washers make this kit suitable for use in the engine bay and under-hood environments common to Suburban, Yukon, Tahoe and Escalade platforms.

How does this kit stop refrigerant loss while keeping the front A/C functional?

By replacing the rear line connection with an OE-style block-off assembly, the kit closes the circuit to the rear evaporator without altering or disconnecting the front air conditioning lines. That preserves the front loop and prevents refrigerant escape. Installation is reversible if the rear system is restored later.

• Caps the rear line connection point to seal the system.
• Uses HNBR washers for long-term leak resistance.
• No changes required to front A/C plumbing or components.
• Removable hardware allows future reinstallation of rear components.

What materials and parts are included for durability and fit?

The kit includes stainless steel fasteners, CNC-machined aluminum fittings and nitrile-hydrogenated butadiene (HNBR) sealing washers engineered for automotive cooling systems. These choices resist corrosion, tolerate under-hood heat, and maintain sealing performance better than standard rubber washers.

• 2x M8 flange nuts and 2x hex head bolts in 304 stainless steel.
• 2x precision-machined aluminum block-off fittings.
• 2x German-made HNBR washers designed for refrigerant applications.
• Printed instruction sheet included for installation guidance.

How difficult is installation and what tools are needed?

Designed for technicians and experienced DIYers, the kit installs where the rear A/C lines join the vehicle. No special modifications are required; standard hand tools handle the bolts and nuts. The package supplies instructions to walk you through the process step-by-step.

• Typical installation time: short — a competent technician can complete it quickly.
• Hand tools required: ratchet, appropriate sockets/wrenches, torque wrench recommended.
• Instructions included in the package and downloadable on the product page.
• Reversible installation allows future restoration of rear HVAC components.

Which vehicle models and years is this compatible with?

This block off kit was engineered to fit the rear A/C line connections used on many 2014–2019 GM full-size SUVs. Verify fitment against vehicle specifications before purchasing, and consult the included guide for model-specific notes.

• Compatible with 2014–2019 Chevrolet Suburban and Tahoe models.
• Compatible with 2014–2019 GMC Suburban 1500/2500 and Yukon Denali XL.
• Compatible with select 2014–2019 Cadillac Escalade rear A/C setups.
• Check vehicle fit notes and photos in the listing before installation.

Who is this for: This 3mirrors Rear AC Block Off Kit is intended for owners, fleet managers and technicians who need a reliable, OEM-style solution to isolate a failed or removed rear air-conditioning circuit on compatible GM SUVs. It’s a practical choice when you want to keep the front A/C operational, avoid unnecessary evaporator replacements, or prepare a vehicle for rear HVAC removal with a durable, serviceable seal.