Thermostat Gasket SIERRA 18-2552-9

Compatibility

The SIERRA 18-2552-9 thermostat gasket is a critical component ensuring the seal of the cooling system in many popular outboard motors. This product is designed for thermostat housings equipped with a flat cover, which is standard in MERCURY MCM engines and GM inline four-, six-, and eight-cylinder configurations. The kit includes 2 pieces, facilitating comprehensive seal replacement during servicing.

Please note that compatibility should always be verified by the manufacturer's catalog number 18-2552-9 or the original OE number. If you have any doubts regarding fitment for a specific engine model, contact our store support to select the correct part.

Installation and Operation

• Original SIERRA quality – guarantees durability and perfect fit.
• Set of 2 pieces – allows for replacing gaskets in both housings simultaneously.
• Effective protection – prevents engine overheating and fluid leaks.
• Easy installation – gasket replacement is a quick repair operation.

A properly installed 18-2552-9 gasket protects against pressure loss in the system. We recommend cleaning the surfaces before installation and checking the condition of the thermostat. Regular replacement prevents costly breakdowns.