Rear Cover Coolant Seal Kit, LML Duramax | 2011-2016

Rear Cover Coolant Seal Kit, LML Duramax | 2011-2016

This kit includes the coolant seals that seal the engine rear cover to the block on the 6.6L Duramax LML. It has 2 genuine GM 12644448 rear cover coolant seals (the green water jacket seals) plus the rear block seal. These seals keep coolant in where the water jacket passages cross between the rear cover and the block. When they harden or are reused, coolant leaks from the back of the engine. Replace them any time the rear engine cover is removed.

Key Features

• 2 genuine GM 12644448 rear cover water jacket seals (green)
• GM 12644448 replaces 12627895
• 1 rear block seal
• Direct-fit replacement; 2 coolant seals required per engine

Benefits

The rear cover has to come off for jobs at the back of the engine, and these seals rarely seal a second time once they've been compressed. A slow coolant leak at the back of the engine is easy to mistake for a heater hose or water pump leak, and fixing it later means taking the rear cover off again. With both coolant seals and the block seal in one bag, the rear cover goes back on with every seal new. Replace if worn or damaged.

Frequently Asked Questions

How many seals does the LML use here?
The rear cover uses 2 of the GM 12644448 water jacket seals. This kit includes both, plus the rear block seal.

Can I reuse the old seals?
We don't recommend it. Once the seals have been compressed and heat-cycled, they often won't reseal, and a coolant leak means removing the rear cover again.

Fitment

Fits 2011-2016 Chevrolet Silverado and GMC Sierra 2500HD and 3500HD with the 6.6L Duramax LML. 2 coolant seals required per engine.

What's Included

• (2) Genuine GM 12644448 rear cover coolant seals
• (1) Rear block seal

For warranty information or to submit a claim, see our Warranty Form.