On the 13th-gen F-150 the thermostat is a plastic housing bolted to the front of the engine where the lower radiator hose lands, and the thermostat itself is not serviced separately on most of these engines - you buy the whole housing with a new O-ring. The actual removal is two or three small bolts and a hose clamp. What eats the time is draining the system, pulling the splash shield, and on the 2.7 EcoBoost, working around the tight front-of-engine packaging where coming at it from underneath is far easier than from above.
The mistake people make is the refill. This cooling system holds air easily, and if you just dump coolant in the degas bottle and drive, you get a swinging temp gauge, no heat, and sometimes a false overheat. Use a spill-free funnel, idle it with the heater on high until the fans cycle, and recheck the level cold the next morning. The other common error is cranking the housing bolts down like they are head bolts - they go into aluminum at roughly 89 in-lb and the housing is plastic.
| Item | Type | |
|---|---|---|
| Drain pan 3+ gallon capacity Catches coolant from the radiator drain and the hose you pull off. | Required | shop |
| Floor jack 2-ton minimum Lifts the truck for radiator draining and under-hood access on 2.7/3.5 EcoBoost. | Required | shop |
| Jack stands 3-ton pair Supports the truck while you work under the front end. | Safety | shop |
| Socket set 7, 8, 10, 13 mm 6-point, 1/4 in and 3/8 in drive Engine cover, air intake, splash shield and thermostat housing bolts. | Required | shop |
| Ratchet and extensions 1/4 in drive, 3 in and 6 in extensions, wobble/swivel Reaching housing bolts tucked behind hoses and the front cover. | Required | shop |
| Torx bit set T25, T30 Some splash shield screws, air box and coolant pipe brackets use Torx. | Recommended | shop |
| Trim/push-pin removal tool Plastic pry set Removes the push-pin retainers in the lower engine splash shield. | Recommended | shop |
| Hose clamp pliers Spring/constant-tension clamp pliers, cable-driven preferred Ford uses constant-tension spring clamps on the radiator and heater hoses. | Required | shop |
| Hose removal tool Pick / hose separator Breaks the stuck radiator hose loose without tearing the plastic housing neck. | Recommended | shop |
| Pliers set Needle nose and channel-lock Handles the radiator petcock and clips on coolant lines. | Recommended | shop |
| Torque wrench 1/4 in drive, 20-200 in-lb Housing bolts thread into aluminum and are low-torque. | Required | shop |
| Spill-free coolant funnel Universal radiator/degas bottle kit Fills and burps the system through the degas bottle without airlocks. | Required | shop |
| Scraper and shop towels Plastic scraper Cleans the sealing face on the block or cover without gouging aluminum. | Consumables | shop |
| Thermostat with housing and seal Motorcraft RT-1268 style assembly; engine-specific part number Ford sells the thermostat as an assembly with the plastic housing and O-ring on most of these engines. | Parts | shop |
| Engine coolant Motorcraft Orange, WSS-M97B51-A1 (yellow VC-13DL-G on some later builds); 2-3 gal prediluted Refills the system; do not mix with green or pink coolant. | Consumables | shop |
| Distilled water 1 gallon For mixing concentrate or topping off. | Consumables | shop |
| OBD-II scan tool Live data capable Confirms coolant temp rises and stabilizes, and clears any P0128 code. | Recommended | shop |
| Safety glasses and nitrile gloves Hot coolant is under pressure and is toxic. | Safety | shop |
All four engines use 8 mm or 10 mm head housing bolts and the same basic tool kit. The 5.0 V8 housing sits on the front cover near the water pump and is reachable from above once the intake tube is out; the 3.3 and 3.5 Ti-VCT V6 housing is at the front of the block and usually comes out from below. The 2.7 and 3.5 EcoBoost are the tightest - plan on removing the lower splash shield and working from underneath, and on the 3.5 EcoBoost you may need to unbolt a coolant crossover bracket first.
| Thermostat housing bolts (most 13th-gen engines) | 89 in-lb (10 Nm) - verify in the service manual for your engine |
| Radiator drain plug (petcock) | Hand tight only |
| Lower engine splash shield fasteners | Snug, about 44-53 in-lb (5-6 Nm) |
| Battery negative terminal nut | verify in the service manual |
The 8 mm and 10 mm housing bolt heads and the 10 Nm / 89 in-lb range are typical for all four engines in this generation, but confirm the exact bolt count, thermostat part number and torque for your specific engine and build year in the Ford workshop manual.
Roughly 3 to 4 gallons depending on engine, but a thermostat job that only drains the radiator typically takes back 2 to 3 gallons of prediluted Motorcraft orange coolant. Buy three gallons so you have enough to top off after the first drive.
On most 13th-gen F-150 engines Ford supplies the thermostat as an assembly molded into the plastic housing, so you replace the whole unit. A few aftermarket kits offer a separate stat and seal, but the factory design is an assembly - check your part number before ordering.
A stuck-open thermostat gives slow warmup, weak heat and a P0128 code; a stuck-closed one overheats quickly and can push coolant out of the degas bottle. A temp gauge that never reaches mid-scale in cold weather is the classic stuck-open sign.
Yes. Fill through the degas bottle with a spill-free funnel, idle with the heater on max heat until the cooling fans cycle and the upper hose is hot, then let it cool and set the level at the COLD FILL line. Recheck cold after a day of driving.