LB7 | LLY Duramax Allison Transmission Cooler Lines – Fleece Performance FPE-TL-LB7-LLY

Stop the leaks and upgrade your cooling system. Factory transmission cooler lines on 2001–2005 LB7 and LLY Duramax trucks are a well-known weak point. Heat, vibration, and age cause them to crack, leak, or fail — putting your Allison transmission at risk of low fluid levels and expensive damage.

The Fleece Performance FPE-TL-LB7-LLY Allison Transmission Cooler Lines deliver a complete, heavy-duty replacement solution. These high-flow, flexible lines are built to eliminate leaks while improving fluid flow and cooling efficiency for your Allison 1000 transmission.

Key Benefits:

• Eliminates common factory line leaks that plague LB7 and LLY trucks
• High-flow 5/8" ID design improves transmission fluid circulation and cooling
• Flexible construction withstands heat, pressure, and vibration far better than rigid factory lines
• Complete kit includes every fitting needed for both stock radiators and popular Setrab aftermarket coolers
• Restores reliable transmission cooling and gives you peace of mind on the road or at work

Kit Includes:

• 5/8" ID high-flow transmission cooler lines
• (6) 7/8"-14 O-ring to -10AN fittings
• (2) 3/4"-16 O-ring to -10AN fittings
• (2) 1/2" NPT to -10AN fittings
• (2) M22x1.5 to -10AN Setrab fittings
• (2) Large OD washers
• (1) Double hose clamp
• (2) Locking cable ties

Vehicle Fitment:

• 2001–2004 GM 6.6L Duramax LB7
• 2004.5–2005 GM 6.6L Duramax LLY
• Chevrolet Silverado 2500HD / 3500HD & GMC Sierra 2500HD / 3500HD with Allison transmission

Note: This kit fits trucks with the factory radiator or Setrab-style aftermarket coolers. Some non-standard aftermarket radiators may require additional adapter fittings (FPE-TL-ST available separately).