Radium Radiator Caps
The radiator cap is an essential part of an upgraded cooling system. Radium caps are engineered to safely improve cooling efficiency by managing the boiling temperature. A higher radiator pressure effectively raises the coolant boiling point, providing an extra safety margin and preventing air pocket cavitation at the water pump.
NOTE: Traditionally, "radiator" caps are mounted to the radiator but can also be found on coolant expansion tanks
Each OEM replacement radiator cap is manufactured from stamped stainless steel for durability. All 18-0076-X1X radiator caps are electroplated black.
Unlike OEM caps which use natural rubber gaskets, these radiator caps feature premium silicone sealing elements for long lasting durability.
Available with 3 different pressure relief springs:
1. 1.1Bar (16.0psi)
2. 1.3Bar (18.9psi)
3. 1.5Bar (21.8psi)
HPS Reinforced Silicone Radiator and Heater Hose Complete Kit Mazda 93-95 RX7 FD3S, 57-1491