Coolant expansion tanks are necessary for proper air bleeding in applications that utilize a rear mounted radiator or a low mounted radiator such as a V-Mount. However, expansion tanks are also valuable if integrated in a common radiator setup. To allow heat expansion, traditional coolant systems require air to be present in the top portion of the radiator during low temperatures. A coolant expansion tank permits the radiator to be 100% filled with coolant in all conditions.

This Radium Coolant Expansion Tank holds 1240mL. It is a multi-piece design constructed of CNC billet 6061 aluminum. 

A pressure cap is not included. The CNC billet receiver is compatible with Type-A "radiator" caps, as shown HERE. The tank features two internal chambers. These chambers are NOT isolated from each other. There are cross-over passages at the top and bottom. 

NOTE: This product is not a coolant overflow tank. Instead, it is designed to be a part of the pressurized coolant system.

PRESSURE CAPS

The optional Radium Engineering pressure caps (sold separately) allow the user to select a range of pressure. The purpose of a high pressure cap is to increase the boiling point in the cooling system providing improved cooling efficiency. Each cap is manufactured from stainless steel with a race proven high pressure valve. This is something to consider when tracking the vehicle in extreme conditions. For more information, go HERE.

Radium Pressure Cap - 1.1 Bar (110 kPA, 15.6 psi)
Radium Pressure Cap - 1.3 Bar (130 kPA, 18.9 psi)
Radium Pressure Cap - 1.5 Bar (150 kPA, 21.8 psi)

The coolant tank has the following ports

• 6AN ORB (9/16"-18) top port. This is the inlet for incoming hot water and is a natural bleed for the system.
• 10AN ORB (7/8"-14) bottom port (opposite the inlet port) This is the drain back outlet. It would typically plumb to the water pump inlet fitting on the suction side.
• 10AN ORB (7/8"-14) bottom port (under the inlet port). This is not commonly used. If applicable, connect it to the highest point of the engine. This will allow any air bubbles trapped in the radiator or engine to travel up to the coolant tank.
• Barbed cap fitting. This is the overflow/purge port

• Billet Aluminum Coolant Tank
• Anodized Aluminum Mounting Bracket
• Water Level Window, Height: 4.6" (118mm)
• Type-A Pressure Cap Receiver
• Aluminum Pressure Bleed 1/4" Barb
• Stainless Steel Hardware