2021 GMC Sierra 1500 A/C Refrigerant and Oil Specifications

Quick Answer

• Refrigerant Type: R-1234yf
• System Charge: 21.16 oz (600g)
• PAG Oil Type: PAG 46
• Oil Capacity: 6.8 oz (200mL)
• Low-Side Port: Near the firewall, on the passenger side
• High-Side Port: In front of the passenger side shock tower

Why R-1234yf Matters

The 2021 GMC Sierra 1500 uses R-1234yf refrigerant, a newer standard that has replaced R-134a in most vehicles manufactured after 2014. This change was driven by the Environmental Protection Agency (EPA) due to R-1234yf's lower global warming potential. While better for the environment, R-1234yf is more expensive and has a higher flammability rating than its predecessor. It also requires specialized equipment for service, including a dedicated recovery machine that can handle this specific refrigerant.

Recharge Procedure

A proper A/C recharge is not a simple top-off. The system must be fully evacuated to remove any air or moisture, which can cause significant damage to the compressor and other components. An accurate charge is then added by weight, not pressure, using a digital scale. Pressure readings can be misleading and often result in an undercharged or overcharged system, both of which can lead to poor performance and costly repairs.

Common A/C Problems for This Vehicle

The 2021 GMC Sierra 1500 is known for a few common A/C issues:

• Compressor Failures: The A/C compressor is the heart of the system, and failures can be caused by leaks, improper refrigerant levels, or internal wear.
• Condenser Issues: The condenser, located in front of the radiator, is susceptible to damage from road debris. A clogged or leaking condenser will prevent the refrigerant from properly cooling.
• Evaporator Leaks: The evaporator, located inside the dashboard, can develop leaks that are difficult to detect. A musty smell from the vents is a common symptom of an evaporator leak.

When to Call a Pro

While some basic maintenance can be done at home, A/C system repairs should be left to certified professionals. The EPA requires anyone servicing an A/C system to have a Section 609 certification. A professional technician will have the proper equipment and expertise to diagnose and repair your A/C system safely and effectively.

Disclaimer: A/C systems contain high-pressure refrigerant and should only be serviced by trained and certified professionals. Improper handling can result in serious injury.

Find a certified A/C shop on Repairius.