Four Seasons 85139 Engine Coolant Thermostat Housing

Thermostat Housing for Ford and Mazda Applications

Four Seasons 85139 is an engine coolant thermostat housing built from plastic and thermoplastic materials for a direct-fit cooling system repair. It includes the gasket or seal and is supplied without a thermostat, making it a practical replacement for worn or cracked housing assemblies on select Ford, Mercury, and Mazda vehicles.

This thermostat housing meets or exceeds OEM requirements and is listed for applications such as the Ford Ranger, Explorer, Explorer Sport Trac, Mustang, Mercury Mountaineer, and Mazda B4000. Four Seasons Thermostat Housing 85139 is also cross-referenced to Gates CO34738 for the same application.

Key Features

• Engine coolant thermostat housing, part number 85139
• Plastic and thermoplastic construction
• Gasket or seal included
• Thermostat not included
• Style: without thermostat
• Meets or exceeds OEM specifications
• Bolt hole center to bolt hole center: 3.438 in.
• Designed for select Ford Ranger, Explorer, Mustang, and Mercury Mountaineer applications

Detailed Description

Four Seasons 85139 is a thermostat housing for cooling system service on select Ford Ranger, Ford Explorer, Ford Explorer Sport Trac, Ford Mustang, Mercury Mountaineer, and Mazda B4000 models. The housing is made from plastic and thermoplastic materials and uses an included gasket or seal for installation. Because the thermostat is not included, this part is intended for repairs where the thermostat is being reused or replaced separately. The housing is listed with a 3.438-inch bolt hole center-to-bolt hole center measurement and is built to meet or exceed OEM standards.

Four Seasons Thermostat Housing 85139 is a fitment-based replacement for 2001-2011 Ford and Mercury applications and 2004-2008 Mazda applications, including Ford Ranger, Explorer, Explorer Sport Trac, Mustang, Mercury Mountaineer, and Mazda B4000 coverage. Use this part when servicing a leaking, cracked, or warped coolant outlet housing on the listed vehicles.

Common Repair Reasons

• Coolant leakage at the thermostat housing
• Cracked or brittle plastic housing
• Warped sealing surface causing seepage
• Failed gasket or seal at the coolant outlet
• Cooling system service on a Ford Ranger, Explorer, Mustang, or Mercury Mountaineer

Installation Notes

Verify vehicle fitment by year, make, model, and sensor-port configuration before installation. Fitment includes 2004-2011 Ford Ranger with 1 switch port, 2002-2006 and 2008-2010 Ford Explorer, 2008-2010 Ford Explorer Sport Trac, 2006-2010 Ford Mustang, 2002-2010 Mercury Mountaineer with 1 switch port, and 2004-2008 Mazda B4000 with 1 switch port. Additional listed coverage includes 2001 and 2007 Ford Explorer and 2007 Ford Explorer Sport Trac with specific build-date notes, plus 2005 Ford Mustang old body style.

Sensor(s) should be replaced at the time of installation, and the thermostat housing is supplied without a thermostat. Confirm the sensor style and port count before beginning the repair.

Quality Assurance

Four Seasons 85139 is an OEM-style replacement thermostat housing built to meet or exceed original equipment requirements for the listed applications. It is engineered for direct replacement service on compatible Ford, Mercury, and Mazda cooling systems.