A-Premium Aluminium Thermostat Housing Assembly for Chevrolet GMC Hummer (2004–2012) — Includes Thermostat & Gasket

A-Premium's upgraded aluminum thermostat housing assembly is a complete replacement unit that includes the thermostat and gasket, designed to restore reliable engine temperature control on compatible Chevrolet, GMC and Hummer models.

If your vehicle is experiencing overheating, coolant leaks at the housing, or an unreliable temperature reading after years of service, this direct-fit assembly provides a durable alternative to aging plastic housings. Machined from aluminum and delivered with the thermostat and gasket installed, the unit replaces OEM part numbers 902-847, 12622316, 440180 and restores factory-style function without extensive modification.

How will this housing assembly improve my vehicle's cooling system?

The upgraded aluminum construction resists warping and cracking better than many OEM plastic housings, reducing leak risk and maintaining consistent coolant flow paths. Precise machining and a matched thermostat ensure predictable open/close behavior for stable operating temperatures.

• Aluminum body reduces thermal expansion and deformation.
• Includes thermostat and gasket for immediate installation.
• Manufactured to fit OEM mounting points and coolant passages.

Which vehicles and OEM references does it fit?

This assembly is made to be compatible with specific GM midsize trucks and Hummer H3 models across 2004–2012 model years, replacing the listed OEM reference numbers for correct fitment. Always verify fitment against your vehicle's VIN or existing part number before purchase.

• Chevrolet Colorado: 2004–2012 models.
• GMC Canyon: 2004–2012 models.
• Hummer H3: 2007–2010 and H3T: 2009–2010 compatible.
• Replaces OEM# 902-847, 12622316, 440180, 902847.

What should I know before installing this thermostat housing assembly?

Preparation and correct procedure help prevent damage and leaks. Clean the mounting surface and remove old gasket material and debris; inspect bolt holes and mating surfaces for damage. After installation, cycle the thermostat and check for leaks while the engine reaches normal operating temperature.

• Remove all old gasket material; ensure screw holes are clean to avoid cracking.
• Follow torque specifications for fasteners and use new gasket supplied.
• Run the engine to operating temperature and inspect for coolant leaks and proper thermostat operation.

What warranty and quality assurances does A-Premium provide?

A-Premium backs this assembly with a one-year unlimited-mileage guarantee and subjects parts to hardness and crush tests to verify structural integrity. The warranty covers manufacturing defects, giving added confidence after installation.

• One-year unlimited-mileage warranty from A-Premium.
• Quality control includes hardness and compression checks.
• Supplied as a complete kit—housing, thermostat and gasket—for convenience.

Who is this for: This aluminum thermostat housing assembly is aimed at owners and technicians working on Chevrolet Colorado and GMC Canyon trucks (2004–2012) or Hummer H3/H3T models who want a stronger, longer-lasting replacement for worn or cracked plastic housings. It suits DIY mechanics replacing a leaking or failed housing, fleet maintenance shops seeking dependable OEM-fit parts, and anyone restoring cooling-system reliability without modifying original mounting points.