Dorman coolant thermostat housing assembly is thoroughly designed for improved durability and resistance. The original assembly typically requires replacement due to the weak plastic construction; which eventually leads to cracks in the small diameter tube and shallow gasket groove. Dorman addresses this common failure mode by upgrading the assembly's housing material from plastic to metal to prevent premature failure of the gasket area and to eliminate cracks in the diameter tube. Additionally, the Dorman Coolant Thermostat Housing Assembly is available as a complete kit, featuring an integrated sensor, thermostat, gasket, and O-ring for a complete repair.