Johnson Pump AirV 4-550 Flex Mount - 12V

The Johnson Pump AirV 4-550 Flex Mount 12V is a compact, high-output circulation pump engineered for engine cooling, heating, and fluid transfer systems in marine, automotive, and industrial applications. Built for mechanics who demand reliable performance in tight engine bays, this flex-mount design accommodates multiple installation orientations without sacrificing flow rate or durability. Whether you're upgrading a classic car cooling system, modernizing a marine engine loop, or optimizing auxiliary hydraulic circuits, the AirV series delivers consistent 12-volt operation across a wide temperature range.

The 4-550 model features a flexible vibration-isolation mounting system that reduces noise transmission to the chassis—critical when integrating aftermarket cooling upgrades or auxiliary systems into vehicle platforms. With a displacement rating of 550 cubic centimeters per revolution, this self-priming pump generates sufficient head pressure and flow for both pull and push cooling configurations. The 12V electrical architecture ensures compatibility with standard automotive electrical systems, delivering reliable continuous operation without drawing excessive amperage. Johnson's sealed bearing construction and corrosion-resistant internals provide extended service life even in harsh saltwater or high-vibration environments.

This pump excels in custom engine builds, vintage car restoration, and marine repower projects where factory cooling capacity falls short of upgraded power outputs. The flex-mount footprint (11 x 7 x 12 inches, weighing 6.1 lbs) fits tight spaces without requiring extensive bracket fabrication, making it ideal for engine bay modifications where real estate is premium. Installation straightforward: source 12V positive/ground, plumb inlet and outlet ports using compatible hose (typically 3/4-inch or 1-inch depending on system design), and secure the mounting feet using the integrated flex bushings. Verify coolant type compatibility before operation to avoid seal degradation.