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The water outlet, water neck, or thermostat housing requires a gasket to seal properly.



What is a Water Outlet Gasket?

After removing the water neck, you are likely to find a gasket, or parts of a gasket, stuck to its mating surfaces. Old gasket material may be stuck to the engine as well. This gasket is the water neck gasket. It needs to be replaced every time you remove the water neck, either with a ready to use OEM-style gasket or a sealing product.

Be sure to verify compatibility with your vehicle using a workshop manual before using sealant to replace your water neck gasket. Some sealant-type products are ineffective for making gaskets, depending on the specific application.

How do Water Outlet Gaskets Work?

Metal parts simply do not have room to bend, even a little bit, when torque is applied to their fasteners. When parts contain fluid, gaskets and seals are required to ensure the fluid does not leak. Gaskets enable irregular metal surfaces to create a seal when bolted together. Gaskets are made from paper, copper, aluminum, plastic, silicone, rubber, o-rings or other materials that compress and seal when force is applied to a part by torqued fasteners.

After removing the water neck or outlet, you may need to use a plastic gasket scraper to remove the old gasket before installing your new gasket, new thermostat, and factory thermostat housing.

How are Water Outlet Gaskets Made?

Factory-grade, computer-aided die-cutting equipment is often used to make mass-produced gaskets for OEM and aftermarket applications. Alternately, you can also make your own gaskets using silicone-based gasket making material squeezed from a tube or applied with a brush.

Why do Water Outlet Gaskets Fail?

  • Improper installation.
  • Heat, oxidation, age, and vibration may cause the gasket to fail under normal driving conditions.
  • The gasket should be replaced or remade whenever the water neck is removed, as when replacing a malfunctioning thermostat.

What are the Symptoms of Water Outlet Gasket Failure?

  • A coolant leak that you trace back to the water neck housing.
  • Look closely at a leaking water neck housing to determine if the leak is coming from a crack in the housing, a failing gasket, or a loose coolant hose.
  • The engine may overheat due to a loss of pressure and coolant.

What are the Implications of Water Outlet Gasket Failure?

  • Every time your engine overheats, you risk major damage to its internal components.
  • Coolant is hazardous to neighborhood animals, pets, and children.
  • Frequent coolant top-offs increase vehicle operating costs.

Don’t panic if you see coolant underneath your vehicle. Do your best to clean up the spill, then pop your hood and have a look around. Attempt to trace the leak to its source and determine the cause. Call a tow truck and schedule an appointment if you’re not sure how to address this problem yourself.

If you have questions or concerns about water outlet gaskets or any of your vehicle’s components, come into your local Pep Boys where we can answer any question, help you find any part, or perform any vehicle service you might need.