Radium Engineering 18-0076-A15 Radiator Cap Type-A 1.5 Bar 21.8 PSI Black

Vehicle Fitment

• Universal fit - compatible with any vehicle using a mini size (32mm ID) radiator neck with a Type-A cap style
• Common Type-A applications include: Subaru WRX / WRX STI (2015+), Mitsubishi Lancer Evolution (Evo X), Honda/Acura K-series swaps, and many Japanese performance vehicles with mini-size radiator necks

Fitment Notes

• Type-A cap style only - Radium offers two cap styles (Type-A and Type-B); verify which style your radiator or coolant tank uses before ordering. Type-A is the standard mini-size cap used on most Japanese performance vehicles
• Designed for mini size (32mm ID) radiator necks only - does not fit large-bore OEM-style radiator necks
• Can be used on radiators or coolant expansion tanks that accept a Type-A style pressure cap
• Available in three pressure ratings - 1.1 Bar (16.0 PSI), 1.3 Bar (18.9 PSI), and 1.5 Bar (21.8 PSI); see 18-0076-A11 and 18-0076-A13 for lower pressure options
• Higher pressure ratings raise the coolant boiling point, providing additional thermal headroom under hard use - only use the highest rated cap your cooling system is designed to handle

Features

• 1.5 Bar (21.8 PSI) pressure rating - the highest available in the Radium cap lineup; raises coolant boiling point for maximum thermal safety margin on track-driven vehicles
• Prevents air pocket cavitation at the water pump under high-load, high-temperature operation
• Stamped stainless steel construction for durability and corrosion resistance - superior to OEM stamped steel caps
• Black electroplate finish matches Radium's broader product line for a clean, coordinated underhood appearance
• Premium silicone sealing elements replace the natural rubber gaskets found on OEM caps - silicone provides significantly longer service life under high heat and chemical exposure
• Direct OEM replacement form factor - installs exactly as the factory cap

Specifications

• Part Number: 18-0076-A15
• Cap Style: Type-A (mini size)
• Neck ID: 32mm
• Pressure Rating: 1.5 Bar (21.8 PSI)
• Body Material: Stainless steel (stamped, black electroplated)
• Sealing Elements: Premium silicone (replaces OEM rubber)
• Finish: Black electroplate
• Quantity: Sold individually (1 cap)
• Warranty: 1 Year Limited

Included Components

• 1x Radium Engineering Type-A 1.5 Bar Black Radiator Cap

Product Description

The Radium Engineering 18-0076-A15 is a high-performance Type-A radiator cap rated at 1.5 Bar (21.8 PSI) for mini size (32mm ID) radiator necks. Manufactured from stamped stainless steel with a black electroplate finish and premium silicone sealing elements, it replaces OEM rubber-gasketed caps with a more durable, heat-resistant alternative that maintains consistent pressure at the cooling system's highest rating. The elevated 1.5 Bar rating maximizes the coolant boiling point for track-driven and high-performance street applications where additional thermal headroom is critical. Compatible with any vehicle using a Type-A mini-size radiator or coolant tank neck - commonly found on Subaru WRX/STI, Mitsubishi Evo, and many Honda/Acura platforms.

Verify your cap style (Type-A or Type-B) and neck ID (32mm) before ordering. For lower pressure ratings, see 18-0076-A11 (1.1 Bar) and 18-0076-A13 (1.3 Bar). For Type-B style, see the 18-0076-B series.