Functional Description - Pressurized Coolant Bottle

A multi-chambered liquid coolant receiving bottle unitized from upper and lower plastic parts forming part of the closed coolant system of an internal combustion engine. When unitized the bottle comprises a pressurized coolant deaeration chamber separated by a convexly curved stationary pressure wall from the overflow chamber. The chambers are arranged laterally side-by-side and are hydraulically connected to one another by a hose external to the bottle. The upper plastic part forming an upper portion of the coolant chamber supports a coolant filler neck that operatively mounts a pressure cap thereon. The pressure cap has a lower primary seal, an upper secondary seal and a vacuum breaker valve and cooperates with the filler neck so that coolant is transmitted to the overflow chamber from the deaeration chamber when the coolant of the system expands and from the overflow chamber to the de-aeration chamber when the system coolant contacts and creates a vacuum.