Concave expansion plugs are an absolute necessity for any car owner. These cup type freeze plugs are used to cover the holes left behind from sand casting in order to prevent coolant liquids from leaking. Additionally, they can also help prevent cracks in your engine block by taking off some pressure in cases where the coolant may freeze.
Since they’re made of metal, these expansion plugs need to be replaced when they begin to rust. After a while, this rust can create holes that may cause some dangerous leaking. Whether you’re looking for a 10-pack or a 50-pack, our collection of zinc plated expansion plugs are sure to be the perfect replacement for your vehicle’s engine block. Even if it’s not time for a replacement yet, it’s always nice to have these ready in your garage!