2010-2018 Ram 6.7L Cummins Coolant Tanks

Coolant tanks, caps, level sensors and float switches for the 2010-2018 Ram 2500 and 3500 with the 6.7L Cummins. The one thing to know: the pressurized degas bottle is where trouble tends to show first. Coolant loss there can mean head-gasket seepage, and a cap that will not hold 16 psi can look like a much bigger problem than it is.

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The coolant tank on the 2010-2018 RAM 6.7L Cummins

On the 6.7L Cummins, the coolant tank is a pressurized degas bottle, and the system behind it holds about 29.5 quarts. The 16 psi cap is part of what keeps the boil-over margin where it should be. Because the bottle is pressurized, it is also where head-gasket seepage first shows up as coolant loss. That makes the tank both a part you replace and a place you read for clues. The tanks in this collection are split by year, with separate parts for 2010-2012 and 2013-2018 trucks.

What fails and why

Start with the cap. A cap that holds 5-6 psi instead of 16 cuts the boil-over margin, and a cap that will not hold pressure can mimic other faults. Pressure-test it before you replace anything else. If the cap is good and the bottle keeps losing coolant, look at the head gasket. A gasket starting to lift shows up in the cooling system first: an upper hose that is stiff and pressurized on a cold engine, overheating that acts like an air pocket, and coolant pushed out of the degas bottle. That pattern turns up at 100,000-200,000 miles on trucks that tow hard or have been tuned. A new tank will not fix that, so rule it out first.

Stock replacement vs. upgrade

If the tank is damaged and you want the factory setup back, the Dorman 603-839 coolant recovery tank and the Fleece FPE-CUMM-CLNT-TNK-1318 replacement tank are both listed for 2013-2018 trucks. If you want a tank built to a different standard, the Mishimoto MMRT-RAM-13N is an aluminum degas tank, the G&R Diesel GR67CM3005 is a welded tank with a low-level sensor, and WCFab sells OEM-placement tank kits that mount where the factory bottle did. A WCFab billet aluminum cap rounds it out.

What we carry

Wehrli Custom Fabrication: OEM-placement coolant tank kits WCF100212 (2010-2012) and WCF100628 (2013-2018), the WCF100472 billet aluminum coolant tank cap, and the WCF206-25 low coolant level sensor listed for 2013-2018 6.7L Cummins.
Fleece Performance Engineering: the FPE-CUMM-CLNT-TNK-1318 replacement coolant tank and the FPE-FS-UNIV-2M-SS stainless steel float switch with a two-pin Metripack connector.
Dorman: the 603-839 coolant recovery tank reservoir for 2013-2018.
Mishimoto: the MMRT-RAM-13N aluminum degas tank for 2013-2018.
G&R Diesel: the GR67CM3005 welded coolant tank with low-level sensor for 2013-2018.

Fitment notes

Most tanks here are listed for 2013-2018 trucks only. For a 2010-2012 truck, the WCFab WCF100212 kit is the option in this collection. Check whether the tank you pick includes a low-coolant sensor: the G&R tank does, while the WCFab sensor and the Fleece float switch are sold on their own. Ram 3500, 4500 and 5500 chassis cabs share the engine but use different frames, filters and exhaust routing, so verify chassis-cab fitment separately. When in doubt, confirm by VIN before you order.

Frequently asked questions

Why is my degas bottle losing coolant with no leak I can see?

Pressure-test the cap first, because a cap that will not hold 16 psi can mimic other faults. If the cap passes, look for head-gasket signs: a stiff, pressurized upper hose on a cold engine, overheating like an air pocket, and coolant pushed out of the bottle. The degas bottle is where head-gasket seepage first shows up as coolant loss.

Will a 2013-2018 tank fit my 2011 Ram?

No. The tanks are split by year, and most in this collection are listed for 2013-2018 only. For a 2010-2012 truck, the WCFab WCF100212 OEM-placement kit is the one to look at.

Do I need a new low-coolant sensor with an aftermarket tank?

It depends on the tank. The G&R Diesel tank comes with a low-level sensor. If yours does not, WCFab sells the WCF206-25 low coolant level sensor and Fleece sells a stainless float switch with a two-pin Metripack connector, both listed for 2013-2018 6.7L trucks.

Should I replace the cap when I replace the tank?

Test it at least. The cap has to hold 16 psi, and one holding only 5-6 psi cuts the boil-over margin. WCFab's WCF100472 billet aluminum cap is listed for 2004.5-2024 Cummins trucks if yours fails the test.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.