Wehrli Custom Fabrication WCF100541-CAT Upper Coolant Pipe Kit L5P Duramax Cat Yellow

The Wehrli Custom Fabrication WCF100541-CAT is a fabricated aluminum upper coolant pipe kit finished in bold Caterpillar Yellow powder coat, designed as a direct upgrade for the 2020–2026 L5P 6.6L Duramax diesel engine found in Chevrolet Silverado and GMC Sierra 2500/3500 HD trucks. This kit replaces the factory steel hard pipe and rubber upper radiator hose with a precision-formed aluminum hard pipe that reroutes coolant from the thermostat housing directly to the radiator — improving routing efficiency and eliminating the weak points of the OEM design.

Key Features:

• Replaces the OEM rubber upper radiator hose with a durable fabricated aluminum hard pipe
• Finished in eye-catching Caterpillar Yellow powder coat for a custom engine bay appearance
• Includes custom-formed silicone boots engineered specifically for the 2020+ L5P coolant pipe routing
• Secured with heavy-duty stainless steel T-bolt clamps for a leak-free, reliable seal
• Features the embossed WCFab logo in brushed aluminum finish
• Improved coolant routing — runs from thermostat housing directly to the radiator
• Made in the USA by Wehrli Custom Fabrication

Kit Includes:

• Fabricated aluminum coolant pipe
• Custom-formed silicone boots
• Stainless steel T-bolt clamps
• Powder coat finish (Caterpillar Yellow)

Wehrli Custom Fabrication (WCFab) is a trusted name in high-performance diesel upgrades, known for their precision craftsmanship and industry-leading fitment. This upper coolant pipe kit is a popular functional and aesthetic upgrade for any 2020–2026 L5P Duramax owner looking to ditch the factory rubber hose and add a standout custom look under the hood.