Mahle C31138 Engine Coolant Thermostat Gasket

Engine Coolant Thermostat Gasket for Ford and Mazda

Mahle C31138 is an OEM-standard engine coolant thermostat gasket made from molded rubber for reliable sealing at the thermostat housing. It is a direct-fit sealing solution for select Ford Ranger, Explorer, Aerostar, Bronco II, and Mazda B4000 and Navajo applications.

Key Features

• Molded rubber gasket material for consistent sealing performance
• OEM Standard item grade for factory-style fit and function
• Engine coolant thermostat gasket for thermostat housing service
• Mahle sealing product trusted by OEMs and technicians
• Part number C31138 for accurate ordering and lookup

Detailed Description

Mahle C31138 is built for cooling system service where a dependable thermostat seal is required. As an OEM-standard gasket, it supports proper sealing between the thermostat and housing to help maintain coolant containment on vehicles such as the Ford Ranger, Ford Explorer, and Mazda B4000. The molded rubber construction is selected for sealing consistency in engine coolant applications, and the Mahle name is associated with sealing products used by OEMs and professional technicians. This part cross-references Motorcraft RG-558 for the same application.

What This Gasket Helps Address

• Coolant seepage at the thermostat housing
• Sealing issues after thermostat service
• Leak-related coolant loss around the engine cooling system
• Improper sealing from worn or flattened thermostat gaskets
• Maintenance replacement on Ford Ranger, Explorer, Aerostar, Bronco II, Mazda B4000, and Mazda Navajo applications

Installation Notes and Tips

• Clean the thermostat housing and mating surfaces before installation.
• Inspect the housing for corrosion, pitting, or distortion that can affect sealing.
• Follow the vehicle service procedure for the thermostat housing and coolant refill.
• For optimal performance during installation of Engine Coolant Thermostat Seal, use the included gasket from the set.
• Verify fitment by year, make, and model before installation; this part is listed for 1986-2000 Ford Ranger, 1991-2000 Ford Explorer, 1990-1997 Ford Aerostar, 1986-1990 Ford Bronco II, 1994-2000 Mazda B4000, and 1991-1994 Mazda Navajo.

Quality Assurance

Mahle gaskets are engineered as sealing components trusted in OEM and professional repair environments. C31138 is manufactured to OEM-standard expectations for fit and sealing performance in the specified applications.