If you’ve owned a diesel truck for more than a few years, you already know the pattern. One cooling system part starts acting up, you replace it, and a few weeks or months later something else in the same system goes. It rarely feels random once you’ve lived through it a couple of times. Heat, vibration, and years of towing don’t wear down cooling components on separate schedules. They wear them down together, and they tend to fail together too.
That’s the real story behind SPELAB’s Cooling System Refresh Kit for the 2013–2018 6.7L Dodge Ram 2500 and 3500 Cummins. It isn’t a horsepower kit, and SPELAB isn’t pitching it as one. It’s a way to get ahead of the failure pattern instead of chasing it part by part.
Every mile you put on a heavy-duty diesel truck stresses the cooling system as a whole. This causes the engine bay to run hot. The truck vibrates constantly under load. Coolant cycles through the same hoses, tubes, and reservoir thousands of times a year, expanding and contracting with every heat cycle.
Factory components, especially the plastic and rubber coolant tubes and reservoirs, weren’t built to shrug that off forever. Plastic gets brittle with age. Rubber hardens and cracks. A tank that held pressure fine at 60,000 miles can start seeping at 150,000, right around the same mileage your radiator core is thinning out from the inside.
This is where a lot of owners end up on the reactive treadmill. A hose starts weeping coolant, so you replace it. A month later the radiator starts showing signs of a slow leak, so that gets replaced too. Then the reservoir cracks. Now comes the repair,, which means another trip to the shop and one more time the truck not being available for work or towing. None of it is a surprise if you understand how these parts age, but that doesn’t make it any less frustrating when it keeps happening.
For a truck that regularly tows or hauls, there’s an added layer of risk. An aging cooling system might limp along under light daily driving for a while longer. Put that same system under a loaded trailer on a summer grade, and the margin for error gets a lot thinner. Overheating on the side of the highway with a load behind you is the kind of problem nobody wants to deal with.
SPELAB built this kit around replacing components that tend to go together, rather than waiting for each one to fail on its own timeline. Here’s what you get:
Upper Coolant Tube — Replaces the factory plastic and rubber routing between the engine and radiator. It’s one of the more common failure points on these trucks simply because of where it sits and how much heat it’s exposed to over time.
Aluminum Radiator — The core heat exchanger for the whole system, and a straightforward replacement or upgrade over the factory unit. This is the piece that does the heavy lifting, and SPELAB also recommends having a professional install it given its size and the coolant system work involved.
Coolant Reservoir Tank — Manages expansion and system pressure. It’s small, but a cracked or failing reservoir can cause pressure issues that ripple through the rest of the system.
The kit also includes the installation hardware and accessories for each component, so you won’t have to track down clamps or fittings separately.
You can order the kit in black, red, or silver, depending on what fits your truck’s look.
This isn’t a bolt-and-go part. Once the new components are in, the system needs to be properly drained, refilled, and bled of air before it’s ready to run. That’s standard practice for any coolant system work, but it’s worth planning for if you’re doing the install yourself.
SPELAB also recommends professional installation, particularly for the radiator. It’s not a difficult job for someone experienced with diesel cooling systems, but it involves enough steps and enough coolant handling that a shop install will save most owners time and hassle.
One more note on expectations: this kit is framed as a durability and reliability refresh, not a guaranteed horsepower gain or a specific coolant temperature drop. If you’re looking for dyno numbers or a marketing promise about degrees off your gauge, this isn’t that product. It’s meant to address the parts most likely to fail as your truck ages, before they fail on their own schedule and start costing you money and downtime.
The math here is fairly simple once you look at it from a cost and downtime perspective rather than a per-part perspective. If you know these three components tend to degrade on a similar timeline, replacing them together means one round of labor instead of three, one day off the road instead of several spread across the year, and one predictable cost instead of a string of surprise repair bills.
For a truck you rely on for towing or daily hauling, that predictability has real value. You’re not gambling on which part goes next or when. You’ve addressed the components most likely to give you trouble and can move on to using the truck.
Right now, the 6.7 Cummins cooling system upgrade kit is priced at $594.00, down from $799.00. For an additional discount, you can use the code: affiliate to get an additional 15% off at checkout.
If your fleet or garage includes more than just the Cummins, SPELAB takes the same approach across other diesel platforms. Owners running a Ford 6.7L Powerstroke can find a comparable setup with the 6.7 Powerstroke Cooling System Upgrades kit, and those with a Chevy or GMC 6.6L Duramax LML can look at the LML cooling system upgrade kit built for that platform.
Whichever truck you’re keeping on the road, the underlying logic holds. Cooling systems age as a unit. Addressing them as a unit, before they start failing one by one, is usually the more sensible way to keep a hard-working diesel truck reliable for the long haul.