2017-2019 Ford 6.7L Powerstroke Cooling Parts

Cooling system parts on the 2017-2019 Ford 6.7L Powerstroke

On the 6.7L Powerstroke, the primary loop cools the block, heads, engine oil cooler, turbo, heater core and both EGR cooler stages. The secondary loop cools the air-to-water charge air cooler, the fuel cooler and the transmission oil cooler. Each loop has its own radiator, thermostat and degas bottle, and on 2017-2019 trucks the secondary loop uses a single Motorcraft RT-1239 thermostat. The factory primary radiator hoses are Motorcraft KM-5475 upper and KM-5517 lower, numbers worth having when you cross-reference a replacement.

What fails and why

Before you start replacing hoses and thermostats over a cooling complaint, rule out the fan clutch. It can stick or bind without setting a trouble code. The symptoms are a loud fan roar when you accelerate, a fan running when it shouldn't, lost power and fuel economy, or overheating on a tow when it won't engage. The test is actual fan speed against desired fan speed on a scan tool. EGR cooler flow issues are also on the common-problem list for 2015-2019 trucks; white smoke, coolant loss and a sweet exhaust smell point there, and that needs a proper diagnosis before any parts go on.

Stock replacement vs. upgrade

For a straight repair, OE-style parts get it done: Alliant Power's AP63540 primary thermostat, Dorman's 902-1074 thermostat housing and replacement hoses, Dayco's curved upper and lower radiator hoses, and MAHLE gaskets for the crossovers, thermostat and water pump. Going past stock means pieces like WCFab's billet thermostat housing and Fleece's thermostat housing upgrade, SPE Motorsport's upgraded coolant cap, heater inlet fittings and oil cooler hoses, and SPE's high volume oil cooler. Mishimoto offers both high-temperature and low-temperature primary thermostats; if you're unsure which suits how you use the truck, call before you order.

What we carry

• Thermostats and housings: Alliant Power AP63540 primary thermostat; Mishimoto MMTS-F2D-11H high-temperature and MMTS-F2D-11L low-temperature primary thermostats; SPE Motorsport S100119 low temp, high flow thermostat; WCFab WCF100148 billet housing; Fleece Performance Engineering FPE-FMC-TH-1125 housing upgrade; Dorman 902-1074 housing.
• Hoses and pipes: Dorman upper radiator, reservoir, overflow and center bypass heater hoses; Dayco 74333 upper and 74335 lower curved radiator hoses; SPE S100164 upper and S100227 lower radiator hoses, degas hose kits and a coolant hose reroute kit; Mishimoto silicone overflow hose; WCFab WCF100311 and S&B 83-1011 upper coolant pipes.
• Water pumps: XDP XTRA Cool XD682 primary and XD675 secondary pumps.
• Oil cooler: Dorman 904-381 engine oil cooler with 625-504 inlet and 625-503 outlet lines; SPE S100183 high volume oil cooler and S100315 upgraded oil cooler hoses.
• Gaskets, caps and fittings: MAHLE left and right crossover outlet gaskets, GS33691 crossover pipe gasket set, C32601 thermostat gasket kit and K32581 water pump gasket; SPE upgraded coolant cap and heater inlet fittings; Dorman heater hose clamp kit.
• Kits and electrical: SPE's upper and lower radiator and thermostat kit, and Fleece's cooling fan adapter harness for 2011-2018 trucks.

Parts from No Limit Fabrication and CSF round out the grid.

Fitment notes

Year ranges here run wide, from 2011-2019 to 2011-2026, but several parts are 2017-2019 only, including Dorman's overflow, reservoir and center bypass heater hoses and XDP's XD682 primary pump. The oil cooler lines split too: the Dorman inlet line is listed 2011-2019 and the outlet line 2011-2018, so 2019 owners should check that listing closely. Fleece's fan adapter harness stops at 2018. Match the loop, the year and the position (upper or lower, inlet or outlet, left or right crossover) before you order, and verify by VIN if you're unsure.

Frequently asked questions

How many thermostats does a 2017-2019 6.7L have?

Two. The primary thermostat controls the high-temperature engine loop, and the secondary loop uses a single Motorcraft RT-1239 on 2017-2019 trucks. The Alliant Power and Mishimoto thermostats here are primary units, and a fresh gasket kit such as MAHLE C32601 belongs in the same order.

How do I tell if my fan clutch is the problem?

Hook up a scan tool. A sticking fan clutch sets no code, so you compare actual fan speed to desired fan speed. The factory part changed by build date: YB3189 for trucks built before July 9, 2018 and YB3246 after, so read the door label first.

What are the factory radiator hose numbers?

Motorcraft KM-5475 is the upper and KM-5517 the lower primary radiator hose on 2017-2019 trucks. Use them to cross-reference the Dorman, Dayco and SPE hoses here, and check each listing's year range.

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.