2017 Kenworth W900 A/C Refrigerant and Oil Specifications

Quick Answer

• Refrigerant Type: R-134a
• Refrigerant Charge: 56.0 oz (1588 g)
• PAG Oil Type: PAG 46
• PAG Oil Capacity: 9.8 oz (290 ml)
• Low-Side Port Location: Near the A/C compressor, on the larger diameter line.
• High-Side Port Location: On the smaller diameter line, typically near the condenser in front of the radiator.

Why R-134a Persists in a Post-2014 World

While most passenger vehicles began transitioning to the more environmentally friendly R-1234yf refrigerant around 2014 due to EPA mandates, the heavy-duty truck industry operated on a slightly different timeline. For the 2017 model year, the Kenworth W900 still utilized R-134a. This is good news for owner-operators and technicians from a cost perspective, as R-134a is significantly less expensive than R-1234yf. However, it's crucial to use the correct refrigerant and service equipment. Never attempt to introduce R-1234yf into an R-134a system, or vice-versa.

A/C Recharge Procedure

A proper A/C service is not just about "topping off" the system. Achieving optimal cooling performance and ensuring component longevity requires a specific procedure.

1. Recovery: The first step is always to recover any existing refrigerant from the system using a dedicated R-134a recovery machine. It is illegal and harmful to the environment to vent refrigerant into the atmosphere.
2. Evacuation: Once empty, the system must be placed under a deep vacuum for at least 30-45 minutes. This process boils off any moisture that may have entered the system. Moisture is the enemy of an A/C system, as it can mix with refrigerant and oil to form corrosive acids.
3. Charge by Weight: The single most critical step is recharging the system with the precise weight of refrigerant specified by the manufacturer. For the 2017 W900, this is 56.0 oz (1588 g). Do not use can pressure gauges to determine the charge; this is inaccurate and will lead to under- or overcharging, resulting in poor performance and potential compressor damage.

Common A/C Problems for the Kenworth W900

• Compressor Failures: The A/C compressor is the heart of the system. Due to the high-mileage and demanding nature of over-the-road trucking, clutch and internal compressor failures are common. When a compressor fails, it can send debris throughout the system, requiring a full system flush and replacement of the condenser and receiver/drier.
• Condenser Damage: Located at the front of the truck, the condenser is susceptible to damage from road debris. A bent fin can reduce efficiency, while a puncture will cause a rapid loss of refrigerant.
• Evaporator Core Leaks: Though less common, leaks can develop in the evaporator core, which is located inside the HVAC box in the cab. This is a labor-intensive repair that requires significant disassembly of the dashboard.

When to Call a Professional

While a DIY-minded owner might be tempted to recharge the A/C system, professional service is highly recommended. A certified technician will have the proper equipment to accurately recover, evacuate, and recharge the system by weight. They can also perform crucial leak detection and diagnose underlying issues, like a failing compressor, before they cause a catastrophic failure.

Disclaimer: A/C system service should only be performed by technicians who are EPA Section 609 certified to handle refrigerants. Always wear safety glasses and gloves when working with refrigerants.

Find a certified A/C shop on Repairius.