Four Seasons 39518 A/C Expansion Valve

Four Seasons 39518 Expansion Valve Overview

Four Seasons 39518 is a block-type A/C expansion valve for R134A systems. Built from aluminum and configured without a solenoid, it regulates refrigerant flow to support proper evaporator performance in Mazda applications, including Mazda 3, Mazda 3 Sport, Mazda 6, and CX-5 fitments.

Four Seasons Expansion Valve line parts are built for direct HVAC service work, with OE-style fitment details and application-specific sizing. This 39518 expansion valve matches the listed Mazda R134A applications and meets or exceeds OEM requirements.

Key Features

• Part number: 39518
• Block-type A/C expansion valve
• Aluminum construction and aluminum finish
• R134A refrigerant type
• Style: without solenoid
• Super heat setting: 5.5
• Tonnage: 1.5
• Female O-ring inlet and outlet connections
• Meets or exceeds OEM specifications

Detailed Description

This Four Seasons 39518 expansion valve meters refrigerant into the evaporator to maintain correct system flow in Mazda HVAC systems. It uses female O-ring suction and liquid connections, a two-hole mounting pattern, and application-specific inlet and outlet sizing for service on R134A-equipped vehicles. Common fitments include 2013-2021 Mazda CX-5, 2014-2020 Mazda 6, and Mazda 3 / Mazda 3 Sport applications across the listed years. This part cross-references UAC EX10442C for the same application.

Use this valve when servicing a Mazda A/C system that needs a direct replacement expansion valve with OE-style connection geometry and block-type construction. The Four Seasons 39518 is also referenced by part number 39518 in interchange listings for related aftermarket and OE-style applications.

What It Is Used For

• Restoring correct refrigerant metering at the evaporator
• Addressing weak or inconsistent cabin cooling
• Replacing a valve with restricted or uneven refrigerant flow
• Correcting A/C performance issues in Mazda CX-5, Mazda 6, and Mazda 3 platforms
• Servicing R134A HVAC systems with block-type expansion valve layouts

Installation Notes and Tips

Verify the vehicle’s refrigerant type, connection style, and mounting layout before installation. Confirm the liquid and suction line sizes match the listed O-ring fittings, and inspect the system for contamination or debris that could affect the new valve. Proper evacuation, leak checking, and recharge procedures are important after HVAC service. Confirm fitment for the exact Mazda year and build notes, including exclusions such as Mexican-built 2016-2017 Mazda 3 and Mazda 3 Sport applications and the 2015 Mazda 3 / Mazda 3 Sport through 1/15.

Quality Assurance

Four Seasons 39518 is listed as meeting or exceeding OEM requirements and is backed by the brand’s HVAC replacement part standards for service applications. The part number 39518 is cataloged for confirmed Mazda fitments, including Mazda 6, Mazda CX-5, and Mazda 3 models shown above.