Four Seasons 38618 A/C Expansion Valve

Four Seasons 38618 Expansion Valve for BMW A/C Service

The Four Seasons 38618 expansion valve is a block-type A/C flow restrictor built for R134A systems and OE-style service on select BMW models. It is an aluminum replacement expansion valve with female O-ring inlet and outlet connections, made to meet or exceed OEM requirements.

Key Features

• Brand: Four Seasons Expansion Valve
• Part number: 38618
• Block-type A/C expansion valve for R134A refrigerant
• Aluminum construction with aluminum finish
• Female FIO O-ring connections on suction and liquid ports
• Super heat setting: 5.000
• Meets or exceeds OEM specifications
• Style: w/o solenoid
• Fits BMW 318i, 325e, 325es, 325i, 325is, 325iX, and M3 applications listed below

Product Details

Four Seasons 38618 is part of the Expansion Valve line, a product line focused on A/C refrigerant control components for service and replacement work. This valve regulates refrigerant flow into the evaporator, helping maintain proper system pressure balance and cooling performance in BMW HVAC systems that use R134A. The aluminum body, O-ring sealing surfaces, and OE-style port sizing support direct replacement on the listed BMW 3 Series and M3 applications. This part cross-references BBB Industries 17527 and Focus Auto Parts 95011 for the same application.

Vehicle Fitment

• Fits 1991 BMW M3, N/A
• Fits 1988 BMW M3, N/A
• Fits 1987-1990 BMW 325i, N/A
• Fits 1987-1990 BMW 325is, N/A
• Fits 1988-1990 BMW 325iX, N/A
• Fits 1984-1987 BMW 325e, N/A
• Fits 1986-1987 BMW 325es, N/A
• Fits 1984-1985 BMW 318i, N/A

What It Helps Address

• Inconsistent cabin cooling from a worn or sticking expansion valve
• Improper refrigerant metering at the evaporator
• Pressure imbalance in the A/C circuit
• Reduced cooling output in BMW 325i, 325is, 325iX, 325e, 325es, 318i, and M3 systems
• Leak concerns at aging O-ring style A/C connections

Installation Notes and Tips

Verify refrigerant type, port sizes, and connection style before installation. This valve uses female O-ring fittings with suction inlet and outlet thread diameter No. 10 and liquid inlet/outlet thread diameters No. 6 and No. 8 as listed. Replace worn sealing surfaces as needed, evacuate and recharge the system according to factory service procedures, and confirm proper superheat after installation. Fitment is specific to the BMW applications listed above.

Quality Assurance

Four Seasons lists this expansion valve as meeting or exceeding OEM specifications for the confirmed applications. The part is built for OE-style replacement service in R134A-equipped BMW HVAC systems.