The original coolant thermostat housing assembly on certain Chrysler and Dodge vehicles is made from plastic that becomes brittle over time, eventually leading to cracks. In addition, overtightening the bleeder valve can cause fluid leaks that can damage the cooling system. This Dorman OE FIX thermostat housing assembly is manufactured from corrosion-resistant aluminum to provide increased coolant system protection, and features patent-pending design upgrades that optimize coolant flow and heat transfer.