Moroso Radiator Cap 16 lb pressure-rated — stainless spring, brass retainer, standard filler neck fit

The Moroso 63316 is a 16 lb pressure-rated radiator cap built for standard-size filler necks, featuring a stainless steel spring and a solid brass spring retainer for reliable cooling-system pressure control.

Designed for performance and durability, this radiator cap replaces worn or incorrect caps to help maintain the intended pressure in automotive cooling systems. The 16 pound setting is commonly used in performance and upgraded cooling applications where a slightly higher boiling point of coolant is desired. Moroso engineers this cap to the dimensions of standard filler necks, and it ships from the United States in compact packaging.

How does this radiator cap affect my cooling system performance?

By sealing the cooling system at a specific pressure, the cap raises the coolant boiling point which helps the system resist boiling under higher temperature and load. Maintaining correct pressure helps prevent localized vapor pockets and supports consistent coolant circulation under stress.

• 16 lb pressure rating increases coolant boiling point compared to lower-rated caps
• Stainless steel spring provides consistent pressure response over time
• Solid brass spring retainer resists corrosion where it contacts the spring
• Fits standard-size filler necks for broad vehicle compatibility

What materials and construction ensure durability?

Moroso combines a stainless steel spring with a solid brass spring retainer to reduce corrosion and preserve accurate pressure settings through repeated heating cycles. Robust internal components and a precise seat design are used to maintain a tight seal and long service life.

• Stainless steel spring resists fatigue and rust
• Brass spring retainer offers reliable corrosion resistance
• Precision sealing surface minimizes coolant loss and air ingress
• Manufactured and packaged in the United States

Will this cap fit my vehicle and how do I check compatibility?

The Moroso 63316 is intended for standard-size radiator filler necks—the common size used on many cars and performance vehicles. To verify fit, compare your existing cap or filler neck dimensions and the mounting design; if your vehicle uses a standard cap, this unit should install without modification.

• Check your current cap for a standard-size profile and retainers
• Compare the 16 lb rating to the OEM or recommended pressure for your cooling system
• Measure filler-neck opening if unsure, or consult vehicle manual
• Easy, bolt-on replacement for compatible systems

How do I install and maintain the Moroso 63316 radiator cap?

Installation is straightforward: when the engine is cold, depress any pressure release and rotate the cap into the filler neck until it seats and locks. Periodically inspect the cap for wear, spring tension, and seal condition, and replace if you notice leaks, corrosion, or a soft spring.

• Install only on a cool engine to avoid steam and burns
• Turn until the cap seats and snaps into place for a secure seal
• Inspect annually or during coolant service intervals
• Replace if the spring loosens or the sealing surface is damaged

Who is this for: The Moroso 63316 16 lb radiator cap is aimed at performance-minded drivers, classic-car restorers, and anyone replacing a worn or improperly rated cap on a vehicle with a standard-size filler neck. It suits applications where a 16 lb pressure setting is desirable and where component longevity and corrosion resistance matter. If you need a dependable, metal-constructed cap made with corrosion-resistant internals and simple fitment for standard necks, this Moroso cap is an appropriate choice.