Sierra 18-4458 Exhaust Protector Valve, White, 5 Inch and 6 Inch, Replaces GLM 89260

The Sierra 18-4458 Exhaust Protector Valve is a white exhaust flapper valve built to keep water out of your boat's exhaust system. It uses compounded rubber flapper valves that block water from traveling back up the exhaust hose when the engine is off or idling, protecting the exhaust manifold and engine from water intrusion. The valve is molded from weather resistant EPDM with a UV stabilizer, so it holds up to sun exposure, saltwater, and engine heat without breaking down over time.

This valve is sized to fit 5 inch and 6 inch exhaust hose (127 mm and 152.4 mm). The 5 inch size requires two 45 degree cuts to install properly. A stainless steel clamp is included to secure the valve in place. The 18-4458 is the standard, non-display packaged version of this valve; a display packaged version is offered under a separate part number for retail packaging needs. It is a direct interchange for GLM 89260 and Mallory 9-44002 exhaust protector valves, so it can be used as a replacement wherever those valves are specified.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-4458
• Product Type: Exhaust Protector Valve
• Color: White
• Size: 5 inches and 6 inches (127 mm and 152.4 mm)
• Installation Note: 5 inch size requires two 45 degree cuts
• Material: Weather resistant EPDM with UV stabilizer; compounded rubber flapper valves
• Included Hardware: Stainless steel clamp
• Weight: 0.91 pounds
• Packaging: Non-Display (Display Packaged version available as a separate part number)

Fitment

Designed as a direct replacement for exhaust systems using a GLM 89260 or Mallory 9-44002 exhaust protector valve, fitting 5 inch or 6 inch exhaust hose.

Replaces (OEM)

• GLM 89260
• Mallory 9-44002

Frequently Asked Questions

What sizes does the Sierra 18-4458 exhaust protector valve fit? The 18-4458 fits 5 inch and 6 inch exhaust hose, equal to 127 mm and 152.4 mm.

Does the 5 inch size need any special preparation to install? Yes, when using the 5 inch size of the Sierra 18-4458, two 45 degree cuts are required for a proper fit.

What is the Sierra 18-4458 exhaust protector valve made of? It is made of weather resistant EPDM with a UV stabilizer, with compounded rubber flapper valves that form the water-blocking seal.

Is the Sierra 18-4458 interchangeable with other brands? Yes, the 18-4458 is a direct interchange for GLM 89260 and Mallory 9-44002 exhaust protector valves.

What does an exhaust protector valve do? The compounded rubber flapper valves in the Sierra 18-4458 prevent water from entering the exhaust system through the exhaust hose.

What color is the Sierra 18-4458 valve? The 18-4458 exhaust protector valve is white.

Does the Sierra 18-4458 come with a clamp? Yes, a stainless steel clamp is included with the 18-4458 exhaust protector valve.

How much does the Sierra 18-4458 exhaust protector valve weigh? It weighs 0.91 pounds.

Is the Sierra 18-4458 weatherproof? Yes, it is molded from weather resistant EPDM with a UV stabilizer, making it suitable for continued sun and saltwater exposure.

What is the difference between the 18-4458 and the 18-4458D? The 18-4458 is the standard, non-display packaged version of this exhaust protector valve, while the 18-4458D is the same valve in display packaging.