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HSP Diesel Diesel L5P 2020-2021 Upper Coolant Tube Kingsport Grey
SKU: 637-2-HSP-DG-GVJG
$142.50 USD
Shipping calculated at checkout.
The 637-2-HSP is best known as the HSP Upper Coolant Tube for the 2020-2021 L5P Duramax-equipped Chevrolet and GMC trucks. The Upper Coolant Tube
Why would you need the HSP Upper Coolant Tube for the 2020-2021 L5P Trucks?
The factory upper coolant tube is a piece that just looks out of place. While the factory part works alright, it can fail due to the construction and the overall look just does not do the L5P engine the justice that it deserves.
What does the HSP Upper Coolant Tube do differently?
To start the HSP Upper Coolant Tube is made of aluminum. This was done to prevent cracking that can cause cooling system failures. We also made it out of aluminum because we wanted you to be able to clean up the engine bay in that L5P Duramax.
With powder coat options and the HSP Diesel logo that sits right up top, you can see the difference between the HSP Upper Coolant Tube and the factory piece immediately. We used slight bends to create the perfect drop-in piece.
This creates a piece that will fit with all factory parts and gives the best flow through the Upper Coolant Tube possible. This part requires no modifications to install and can be done quickly with basic knowledge.
What comes with the HSP Upper Coolant Tube?
- (1) Aluminum 2 inch L5P (20-21) Radiator Hose Tube
- (2) 2 inchx3 inch Straight Boot
- (4) 2 inch T-Bolt Clamp
Special note
This only Fits the 2020-2021 L5P engines even though the Vin code is the same. This is due to small changes that were made in the engine bay. Please be sure you are ordering for the correct year truck.
What Does the HSP Upper Coolant Tube fit?
L5P: 20-21 VIN Code Y
How do people know the VIN code?
Engine code is dictated by the 8th character of the VIN number. The 10th character is the year of the truck.
Overview
Maintains factory routing
2 inch OD tubing to match factory hose size
No modifications are necessary
Dress up the engine bay
Metal Replacement
Our Warranty
HSP No BS Limited Lifetime Warranty
At HSP we believe in our products and we stand firmly behind every single one that leaves our facility. For years we have taken care of almost everything & anything that our customers had issues with, but we didn't have a set in stone warranty.
We have always gone above and beyond for our customers which set us apart from the rest.
We will continue that same standard, but now we are taking things to the next level.
questions we get about hsp diesel daily:
Who is HSP Diesel and what makes their products different?
HSP Diesel builds high-flow, made-in-the-USA diesel performance hard parts that solve real-world airflow restrictions. Their components are CAD-designed, flow-tested, and engineered for durability, clean fitment, and consistent performance. Customers choose HSP because the quality, welds, powder coat options, and fitment are more refined than generic diesel aftermarket parts.
Are HSP Diesel products compatible with my truck?
Most HSP Diesel components are designed for GM Duramax platforms (LB7, LLY, LBZ, LMM, LML, L5P). Each product page lists exact year and engine compatibility. If you're not sure which Duramax engine you have, send us your VIN and we’ll gladly confirm fitment before you order.
Do HSP Diesel parts improve performance?
Yes. Upgrades like intercooler pipes, Y-bridges, turbo inlet kits, and intakes dramatically reduce airflow restriction. Most owners see faster spool, cooler EGTs, smoother towing performance, and better throttle response—even on otherwise stock trucks.
Do I need tuning after installing HSP Diesel parts?
Most HSP airflow parts (intakes, charge pipes, Y-bridges, turbo mouthpieces) do not require tuning to install or drive. However, a tune may help the truck take full advantage of the increased airflow. If a part requires tuning—such as a turbo upgrade—the product page will clearly note it.
Are HSP Diesel parts emissions compliant?
Many HSP Diesel components work with factory emissions systems in place. Some turbo-related or race-use parts may not be emissions compliant. Always read the emissions note on the product page and follow local laws before installation.
How long does it take for HSP Diesel parts to ship?
Most HSP parts are built and powder-coated after you order. Standard colors ship sooner, while custom colors may require 2–4+ weeks depending on workload. Lead times are shown on each product page and updated frequently.
What powder coat colors are available?
HSP offers a wide range of standard colors (black, red, white, blue, etc.) plus custom powder coat finishes. Custom colors may add cost and lead time. If you're trying to match an existing part, send us a photo and we can help you choose the closest match.
Do HSP Diesel kits come with everything needed for installation?
Most HSP parts include the clamps, boots, brackets, and hardware required for a clean install. Larger systems—like turbo kits or intercooler upgrades—may require additional supporting parts. Each product page lists everything included in the kit.
Are HSP Diesel parts compatible with other aftermarket brands?
In most cases, yes. As long as the parts use compatible diameters and mounting points, HSP Diesel components integrate well with other brands of turbos, intakes, intercooler systems, and fueling components. If you already have mods installed, tell us what’s on the truck and we’ll check compatibility.
Will HSP Diesel parts help with towing?
Absolutely. Improved airflow reduces EGTs, increases turbo response, and helps the truck pull more consistently under load. Many daily drivers and towing-focused Duramax owners upgrade to HSP specifically for cooling and drivability gains.
What warranty do HSP Diesel products include?
HSP Diesel provides a warranty against workmanship and material defects. If a part arrives damaged or defective, contact us with photos and your order number and we’ll assist in getting it corrected.
Can I install HSP Diesel parts myself?
Many components—like charge pipes, intakes, and coolant tanks—are DIY-friendly. More complex installs (Y-bridges, turbo kits, or tight-tolerance piping) may require professional installation. Review the instructions to make sure you're comfortable with the job.
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