Hedman Hedders Secondary Air Injection Check Valve

Hedman Hedders Secondary Air Injection Check Valves: Exhaust Expertise Applied to Emission Control

When most enthusiasts think of Hedman Hedders, headers, collectors, and mandrel-bent exhaust tubing immediately come to mind. But Hedman’s seven decades of exhaust engineering give the brand a uniquely informed perspective on every component that interfaces with the exhaust stream — including the often-overlooked secondary air injection check valve.

What a Secondary Air Injection Check Valve Does

The secondary air injection (AIR) check valve is a one-way gate positioned between the air pump and the exhaust manifold or catalytic converter. Its job is precise and critical: it allows pressurized fresh air to flow into the exhaust stream, while sealing shut the moment exhaust backpressure builds. As a spring-loaded component, it opens when the air pump pressurizes the system and closes tightly to prevent hot exhaust gases from traveling in reverse. Without a properly functioning check valve, the air pump — typically made of aluminum and plastic — is exposed to exhaust temperatures that can cause rapid, irreversible damage.

The secondary air injection system itself was introduced as an emissions control strategy to reduce unburned hydrocarbons and carbon monoxide leaving the tailpipe, particularly during cold starts when the catalytic converter has not yet reached operating temperature. A functioning check valve is what keeps that entire system operational and your vehicle emissions-compliant.

Why the Check Valve Matters More Than You Think

A failed check valve that sticks open allows hot exhaust gases to flow backward into the air pump, causing rapid pump failure. A valve that sticks closed prevents fresh air from reaching the exhaust, which triggers emission test failures and often illuminates the Check Engine light with codes like P0410. The secondary air injection check valve is, in many ways, the first line of defense for the entire AIR system.

• Protects the air pump from thermal shock and exhaust backflow
• Maintains system pressure for effective secondary combustion of exhaust gases
• Prevents emissions failures by keeping the AIR system functioning during cold starts
• Guards against carbon buildup and internal seal degradation over repeated heat cycles

Hedman Hedders and the AIR System Connection

Hedman’s roots run deep in GM, Ford, and Mopar exhaust applications. Since 1954, the brand has engineered exhaust systems designed to work with factory emissions equipment — not against it. Many of Hedman’s long-tube headers are specifically designed for compatibility with AIR (Air Injection Reactor) systems, a nod to the brand’s commitment to building products that keep vehicles legal and functional on the street. That same philosophy extends to their secondary air injection check valves, which are designed as reliable OE-style replacements that integrate cleanly into the existing AIR system plumbing.

For owners of classic GM muscle cars, trucks, and engine-swapped builds running Hedman headers with A.I.R. ports, sourcing a compatible check valve from the same manufacturer ensures consistent fitment and reliable one-way flow protection. Browse the full Secondary Air Injection Check Valve category or explore the complete Hedman Hedders catalog to find the right components for your build.