Chevrolet K-Series Pickup brake bulb sizes include 3057, 1157, and 2057 configurations, with 921 bulb size for the center high mount stop light. The replacement chart covers vehicle production years spanning 1975 to 2000 with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Chevrolet K-Series Pickup brake light specifications cover four distinct bulb types across the 1975-2000 model years: the 3057, 1157, 2057, and 198.
The 3057 is a dual-filament wedge bulb operating at 12V with a 27W high-filament and 7W low-filament rating. Its T25 wedge base distinguishes it physically from the bayonet-style bulbs also used in this application.
The 1157 uses a BAY15d bayonet base and operates at 12V with filament ratings of 21W and 5W. It is an ANSI-standard dual-filament bulb shared across a wide range of automotive applications.
The 2057 shares the same BAY15d bayonet base as the 1157 but carries higher filament ratings of 26.9W and 8W, making it a higher-output variant of that base type. Despite the physical compatibility of the base, the two bulbs are not rated identically.
The 198 is a miniature T5 wedge bulb rated at 12V and 2W, a significantly lower output than the other brake bulb types specified for this vehicle. It was used on the 1975-1978 model years.
The Chevrolet K-Series Pickup (1975-1978) used the 198 bulb for the brake light position, while the 1979-1982 model years transitioned to the 1157, representing a change in both bulb type and base style.
The 3057 and 1157 are not interchangeable despite both being dual-filament bulbs, as the 3057 uses a T25 wedge base while the 1157 uses a BAY15d bayonet base. The socket design differs between these two types.
The brake light bulb specification alternates between the 3057 and 1157 across several model years in the 1990s, with the 1157 used in 1994-1995 and 1999, and the 3057 used in 1996-1997 and 2000.
The Center High Mount Stop Light (CHMSL) on the K-Series Pickup used the 921 bulb across the 1993-2000 model years. The 921 is a single-filament T15 wedge bulb rated at 12V and 16W.
All bulb types specified for the Chevrolet K-Series Pickup conform to ANSI standards applicable in both the United States and Canada.