Ensuring Expertise Built In , the OTR Coolant Reservoir is an overflow system to contain and manage the excess coolant produced by engine heat expansion. As the engine temperature decreases, the coolant recedes into the radiator, providing optimal performance and longevity. Indicators of other engine issues being seen within the coolant reservoir include an excessively filled reservoir that can lead to system inefficiencies; the appearance of white smoke from the exhaust, suggesting potential engine issues; and the detection of oil within the coolant tank. Indications of a malfunctioning coolant reservoir include a pool of coolant under the truck, suggesting a potential crack or leakage in the tank. If your heavy duty truck is showing any signs of leakage, this heavy duty coolant tank replacement boasts enhanced reliability and performance overtime, withstanding both high temperature heat exposure and vibrations. FleetPride is your First Click in Heavy Duty .