2004.5–2005 LLY Duramax: Intercooler Boots, Radiator Hoses, or Both?

Replacing intercooler boots doesn’t automatically mean replacing radiator hoses. Start with the parts that need attention, then choose the kit that fits the job.

For 2004.5–2005 Chevrolet Silverado and GMC Sierra 2500/3500 pickups with the 6.6L LLY Duramax, Mammoth offers boots, radiator hoses and a combination kit.

Check your application first

Mammoth’s LLY intercooler kits are listed for 2004.5–2005 trucks. Confirm the engine and your truck’s actual plumbing before ordering, rather than relying on “2004 Duramax” alone.

For an LB7, see our LB7 boots and pipe kit guide.

Have a 2006 LLY, replacement intercooler or aftermarket piping? Contact Mammoth before ordering to confirm fitment.

Boots only: replace the flexible connections

The LLY silicone intercooler boot kit includes silicone boots and constant-tension T-bolt clamps. It is designed to replace the stock boots on the listed 2004.5–2005 LLY pickups.

Start here when the repair calls for new boots, not radiator hoses. Inspect the pipes and connections too. If a boot repeatedly slips off, identify the cause rather than assuming another boot will solve it.

Boots and radiator hoses: cover both jobs

The LLY boot and radiator hose combo combines silicone intercooler boots and clamps with upper and lower silicone radiator hoses and their clamps.

The listing specifies compatibility with the factory intercooler. Consider the combo when both the intercooler boots and radiator hoses need replacement. A new intercooler is not included.

Radiator hoses only: keep the repair focused

The 2001–2005 Duramax radiator hose kit includes upper and lower silicone radiator hoses with T-bolt clamps. Its listed applications include 2004.5–2005 LLY Silverado and Sierra 2500/3500 trucks.

Compare this option when the radiator hoses need attention but the intercooler boots do not. These are upper and lower radiator hoses, not turbo coolant lines.

If your LLY is running hot

Do not assume new radiator hoses will solve overheating. A damaged hose may need replacement, but the cause of the temperature problem still needs to be identified. Have the cooling system inspected before buying parts solely to address overheating.

The simple choice

• Boots need replacement? Compare the boot kit.
• Boots and radiator hoses both need replacement? Compare the combo.
• Only the radiator hoses need replacement? Compare the hose kit.

Browse the 2004.5–2005 LLY collection, confirm your application and follow the appropriate installation and service instructions for your truck.