Bullet Proof Diesel LML Duramax Front EGR Cooler (6700012)

Stop replacing failed factory EGR coolers. The Bullet Proof Diesel 6700012 Front EGR Cooler is a direct-fit upgrade for 2011–2016 GM 6.6L Duramax LML engines, built to handle the heat, expansion, and cycling that crack OEM coolers.

This is the front cooler in the LML’s two-piece EGR system and replaces GM part 12635707. It uses Bullet Proof Diesel’s patented H-Core design: helically wound stainless-steel tubes that flex with temperature change instead of fighting it. That reduces stress on the bulkheads and seams—the usual failure points—while packing in more tube surface area for more effective cooling of recirculated exhaust gas.

Key features

• Patented helical H-Core tubing for reliability under thermal cycling
• Stainless-steel construction that resists fatigue and heat-stress failure
• TIG-welded or vacuum-brazed tubes and bulkheads
• Direct-fit replacement—quality-controlled to match factory mounting
• CARB EO D-730-6 (legal for use in California)
• Limited lifetime parts-only warranty

Fitment

• 2011–2016 Chevrolet Silverado 2500HD / 3500HD
• 2011–2016 GMC Sierra 2500HD / 3500HD
• 6.6L Duramax LML (VIN 8th digit = 8)

Important notes

• Gaskets and hardware are not included
• A refundable core charge typically applies
• Confirm you need the front cooler; LML also uses a separate rear cooler

Built as a street-legal, emissions-compliant replacement—not a delete. If your LML is leaking coolant into the EGR path, this is the upgraded cooler designed to last.