2018 Chevrolet Silverado 2500HD A/C Refrigerant & Oil Specifications

Quick Answer

• Refrigerant Type: R-1234yf
• Full System Charge: 21.2 oz (600g)
• PAG Oil Type: PAG 46
• PAG Oil Amount: 6.8 oz (200mL)
• Low-Side Service Port Location: Near the firewall on the passenger side
• High-Side Service Port Location: In front of the passenger side front tire, near the radiator.

Why R-1234yf Matters

Starting in 2014, many manufacturers began transitioning from R-134a to the more environmentally friendly R-1234yf refrigerant. Your 2018 Silverado 2500HD uses R-1234yf, which has a much lower global warming potential (GWP) than its predecessor. However, this change comes with a few important considerations:

• Cost: R-1234yf is significantly more expensive than R-134a.
• EPA Regulations: Due to its cost and environmental benefits, it is illegal to vent R-1234yf into the atmosphere. Proper recovery and recycling are mandatory.
• Equipment: Servicing R-1234yf systems requires a specific, dedicated recovery and charging machine. Shops cannot use the same machine for both R-134a and R-1234yf systems.

Recharge Procedure

A proper A/C recharge is not a simple "top-off." To ensure optimal performance and longevity of your A/C system, the following steps are crucial:

1. Evacuation: The system must be fully evacuated using a recovery machine to remove all old refrigerant and non-condensable gases like air and moisture.
2. Vacuum: A deep vacuum is then pulled on the system to remove any remaining moisture, which can cause serious damage if left in the system.
3. Charge by Weight: The system is then recharged with the precise amount of refrigerant specified by the manufacturer (21.2 oz for your truck). This is done by weight, not by pressure, as pressure readings can be misleading.

Common A/C Problems for This Vehicle

While the A/C systems on these trucks are generally reliable, some common issues can arise:

• Compressor Failures: The A/C compressor is the heart of the system and can fail due to internal wear, clutch issues, or lack of lubrication.
• Condenser Issues: The condenser, located in front of the radiator, is susceptible to damage from road debris, which can cause leaks. Internal clogs can also occur.
• Evaporator Leaks: The evaporator, located inside the dashboard, can develop leaks, which are often difficult and labor-intensive to diagnose and repair.

When to Call a Pro

While some basic A/C diagnosis can be done by a savvy DIYer, any work that involves handling refrigerant requires specialized equipment and certification. If your A/C system is not cooling, it is best to have it inspected by a qualified technician to properly diagnose the issue and prevent further damage.

Disclaimer: It is illegal to work on an A/C system without proper EPA 609 certification. Always wear safety glasses and gloves when working near an A/C system.

Find a certified A/C shop on Repairius.