Trans/Air 210042 4-Ton Expansion Valve (TXV) | R134a External Equalized | 3/8" x 1/2" Male Insert O-Ring | Replaces MEI 16110, Four Seasons 38613 & Blue Bird 210042

Trans/Air 4-Ton Expansion Valve (Externally Equalized) Is your school bus A/C freezing up or blowing warm? The Trans/Air 210042 is the heavy-duty 4-Ton Expansion Valve used in thousands of TA73 series bus air conditioning systems. Why "External Equalization" Matters: Large evaporators (like those in buses) have significant pressure drops. This valve features an External Equalizer Line (1/4" Flare) that reads the pressure at the tailpipe of the evaporator. This ensures the valve feeds the exact amount of R134a needed, preventing the compressor from starving or flooding. Technical Specifications:Capacity: 4 Ton (48,000 BTU)Refrigerant: R134aInlet: 3/8" Male Insert O-Ring (MIO)Outlet: 1/2" Male Insert O-Ring (MIO)Equalizer: External (1/4" Female Flare)Capillary Length: ~15 InchesCross-Reference Guide:replaces Trans/Air: 210042replaces MEI Airsource: 16110replaces Four Seasons: 38613replaces Truck Air: 12-3059Areplaces Omega: 31-10993AMreplaces Global Parts: 3411899replaces UAC: EX 10555CApplication Note: Replaces Blue Bird and Thomas Built buses equipped with Trans/Air TA73 rear or rooftop units. Please verify your fitting sizes (MIO vs. Flare) before ordering.

• HEAVY-DUTY 4-TON CAPACITY: High-output Thermostatic Expansion Valve (TXV) rated for 4 Tons (48,000 BTU). Designed to replace large evaporator cores found in School Buses (Blue Bird, IC, Thomas) and Transit applications.
• EXTERNAL EQUALIZED DESIGN: Features a 1/4" Female Flare (FF) external equalizer port with a 12-inch capillary tube. Essential for balancing refrigerant pressure in large, multi-circuit evaporators to prevent coil freezing.
• FITTING SPECIFICATIONS: Inlet: 3/8" Male Insert O-Ring (MIO). Outlet: 1/2" Male Insert O-Ring (MIO). Right-Angle body configuration for compact installation in Trans/Air evaporator housing units.
• DIRECT REPLACEMENT: Genuine Trans/Air 210042. Directly replaces aftermarket cross-references: MEI Airsource 16110, Four Seasons 38613, Truck Air 12-3059A, Omega 31-10993AM, and UAC EX 10555C.
• OEM-Quality Construction – Durable brass and stainless steel components designed to withstand vibration, pressure, and heat in demanding vehicle environments.