GM 6.2L V8 EcoTec3 Water Pump 12683468 12687631 - Silverado 1500 / Sierra 1500 2019-2022

Overview

A Gen V water pump assembly referenced to OEM 12683468 and 12687631 for 2019-2022 Silverado 1500 and Sierra 1500 applications. Supplied as a replacement engine water pump for the GM L87 6.2L EcoTec3 V8 and the closely related Gen V 6.2L applications noted below. This listing covers the component described here only; hardware such as bolts, seals and gaskets is included only where the specification list says so.

Function

The water pump is the only component moving coolant through the engine and radiator under pressure, so its condition sets how well heat leaves the block. A failing pump usually begins with a weep at the seal, then a bearing rumble, then overheating that is worst at idle and improves with engine speed. On a Gen V V8 the pump sits behind the accessory drive, so a coolant residue trail from the weep hole is the earliest reliable warning.

Specifications as documented

• Component: Engine water pump
• OEM part number: 12683468; 12687631
• Cross-reference: 12699889 and 12707680 recorded as further compatible numbers for this pump on a parts listing
• Engine: 6.2L Gen V V8 - pump is documented against 5.3L and 6.2L Gen V applications
• Model years: 2019-2022 (supplier stated); parts listings extend coverage to 2019-2025 and 5.3L / 6.6L use
• Package contents: 1 x water pump (gasket inclusion not confirmed)

Compatibility

Engine: 6.2L Gen V V8 - pump is documented against 5.3L and 6.2L Gen V applications. Vehicle applications recorded for this part: Chevrolet Silverado 1500, GMC Sierra 1500; also listed for Escalade and Tahoe applications. Model years: 2019-2022 (supplier stated); parts listings extend coverage to 2019-2025 and 5.3L / 6.6L use. OEM reference: 12683468; 12687631. Fitment status recorded at the time of listing: oem number cross-checked to gen v 5.3l / 6.2l application.

Installation

Drain the cooling system before removal and check the mating face on the timing cover for pitting or old sealant. Fit a new gasket dry unless the manufacturer specifies otherwise, torque the fasteners evenly in sequence, and refill with the specified coolant at the correct concentration. Bleed the system properly, run a full heat cycle with the heater open, and re-check the level once the engine is cold.

Fitment notice

Compatibility is stated for the GM L87 6.2L EcoTec3 V8 on the strength of the supplier listing and, where an OEM number is published, a parts-catalogue cross-check. GM built the 6.2L V8 in several forms, and L86, LT1, LT2 and LT4 components are not automatically interchangeable with L87 parts. Before ordering, confirm the engine RPO code and the original part number against the vehicle, and treat this listing as a guide rather than a substitute for that check. Specialist engine repairs should be carried out by a qualified technician.