The SPOOLOGIC Turbo Coolant Feed Line SL-360-021 is a direct-replacement turbo coolant feed line for 2017-2019 6.6L Duramax L5P and L5D applications. Built to OE form and fit, it carries coolant from the block up to the turbo center section using rigid steel legs joined by a flexible hose section, and bolts to the turbo housing at the coolant port. Ships with 1 line-to-turbo gasket, 2 line-to-turbo bolts, 1 line-to-block gasket, and 2 line-to-block bolts. Backed by a 1-Year Limited Warranty.

Why You Replace the Coolant Line — Not Just the Gasket

Coolant lines, gaskets, and mounting hardware are not designed to be reused forever. Here’s what’s actually happening to the parts you’re tempted to put back:

• OE coolant lines corrode and crack from the inside out. The steel tubing runs coolant through the hottest zone of the engine bay, cycling from cold soak to 200°F+ operating temp thousands of times. Internal scale and external road salt eat the tubing until pinhole leaks show up at the crimps or the bends.
• Rubber jumper sections harden and split. The flexible hose section between the rigid steel legs sees the same thermal cycling and eventually goes brittle. When it splits, coolant sprays across a hot turbo — sometimes onto the exhaust manifold — and the truck overheats fast.
• Line-to-turbo gaskets are single-use. The gasket that seals the feed line to the turbo housing takes a permanent compression set the moment it’s torqued down. Reusing the old gasket on the new line leaks coolant onto the turbo center section.
• Mounting hardware corrodes and seizes. The line-to-turbo bolts live in the hottest, wettest part of the engine bay. Fresh hardware torques predictably and comes off cleanly the next time the turbo has to come out.
• Line-to-block gasket is single-use too. Feed-line kits include the second gasket that seals the line to the block-side coolant port. Same rule — new line, new gasket every time.

Component Breakdown — What Each Piece Does

• 1 turbo coolant feed line assembly — rigid steel tubing joined by a flexible hose section with factory-style crimp ferrules and mounting brackets. Carries coolant from the block up to the turbo center section.
• 1 line-to-turbo gasket — seals the coolant line flange to the turbo housing coolant port.
• 2 line-to-turbo bolts — new heat-treated hardware that torques the line flange down to the turbo.
• 1 line-to-block gasket — seals the coolant line flange to the block-side coolant port.
• 2 line-to-block bolts — new heat-treated hardware that torques the line flange down to the block.

Material Technology — Why Each Material Was Chosen

• Rigid steel tubing — the line body is formed steel to OE geometry and welded to mounting brackets in the correct positions so the line clears the surrounding components and drops into the factory brackets.
• Fluoroelastomer-grade flexible hose section — the middle section is coolant-rated hose designed for the thermal cycling and vibration this line sees in service.
• OE-spec crimp ferrules — the crimps at each end of the flexible section are sized and swaged to hold the hose against the steel tubes under the operating pressure of the cooling system.
• Coolant-rated flange gaskets — the included gaskets are the correct material for engine-coolant temperatures and the compression this joint sees when torqued.
• Heat-treated steel mounting bolts — the included bolts are the correct grade, length, and thread pitch for the line-to-turbo and line-to-block joints.

Install Notes

• Drain the cooling system before removing the old line — open the radiator drain and catch the coolant in a clean pan for reuse or disposal.
• Clean the turbo coolant port mating surface with a plastic scraper and a lint-free rag before setting the new line down. Old gasket residue or scale on the port will keep the new gasket from sealing.
• Install the new line-to-turbo gasket dry — no RTV, no thread sealant on the gasket face. The gasket is designed to seal on clean, flat metal.
• Clean the block-side coolant port the same way — the block port has to be clean, flat, and free of old gasket residue for the new gasket to seal.
• Install the new line-to-block gasket dry as well — no sealant on the gasket face.
• Start all bolts by hand before torquing anything, so the line self-aligns without stress on the flanges.
• Follow the GM service manual torque specs for the line-to-turbo bolts. Over-torque cracks the aluminum port; under-torque leaks.
• Refill with the correct GM DEX-COOL specification coolant, bleed the system per the service manual, and inspect the line at every fitting after a full heat cycle.

What’s Included

• 1 turbo coolant feed line assembly
• 1 line-to-turbo gasket
• 2 line-to-turbo bolts
• 1 line-to-block gasket
• 2 line-to-block bolts

Interchange / Cross-Reference

• GM OEM 12691901 — turbo coolant feed line

Features

• Direct-replacement turbo coolant feed line for 2017-2019 6.6L Duramax L5P/L5D applications
• Ships with 1 line-to-turbo gasket and 2 line-to-turbo bolts, plus 1 line-to-block gasket and 2 line-to-block bolts
• OE form and fit — direct replacement, no modifications
• Backed by a 1-Year Limited Warranty

Fits 2017-2019 6.6L Duramax

• 2017 – 2019 Chevrolet Silverado GMC Sierra 2500 3500 6.6L Duramax L5P

1-Year Limited Warranty

Every SPOOLOGIC turbo coolant line is covered by a 1-Year Limited Warranty against defects in materials and workmanship from the date of purchase. Warranty covers replacement of the part only. Warranty does not cover labor, towing, downtime, consequential damages, failures caused by improper installation, failures caused by dirty or damaged mating surfaces, reuse of any included gasket, or use outside the listed fitment.