Thermostat Housing

This procedure covers the removal and replacement of the thermostat housing on the 2011-2014 Ford F-150 with the 5.0L Coyote V8 engine, including coolant drainage, housing removal, and refilling the cooling system.

Warnings

Tools required

Parts

• Thermostat housing assembly × 1 — Use OEM specification
• Thermostat × 1 — Use OEM specification
• Thermostat housing gasket/O-ring × 1 — Usually included with housing
• Coolant hose clamps (if damaged) × 2 — As needed

Fluids

• Motorcraft Orange Coolant — 3 qt

Preparation

1. Ensure engine is completely cold before beginning work
2. Park vehicle on level ground and engage parking brake
3. Disconnect negative battery cable to prevent accidental fan activation
4. Remove engine cover by pulling upward on cover (press-fit clips)
5. Locate the thermostat housing on the front driver side of the engine block, below the intake manifold

Procedure

1. 1

   Drain cooling system
   Place drain pan under the radiator drain plug located at the bottom driver side of the radiator. Open the radiator drain plug by turning counterclockwise and allow coolant to drain completely. If equipped, also open the engine block drain plug. Allow 10-15 minutes for complete drainage.
   Torque spec

   Coolant Drain Plug15 Nm (11 lb-ft)
2. 2

   Remove upper radiator hose
   Locate the upper radiator hose connection at the thermostat housing. Use pliers to compress and slide the spring clamp back approximately 2 inches from the connection point. Twist the hose while pulling to break the seal and remove it from the thermostat housing. Be prepared for residual coolant spillage.
3. 3

   Disconnect coolant bypass hose
   Identify the smaller bypass hose connected to the bottom of the thermostat housing. Compress the hose clamp and slide it back, then remove the hose from the housing. Angle the hose downward to minimize coolant spillage.
   Torque spec

   Coolant Hose Clamps5 Nm (4 lb-ft)
4. 4

   Remove thermostat housing bolts
   Using a 10mm socket, remove the three bolts securing the thermostat housing to the engine block. Note the bolt locations and lengths for reassembly. The housing is located at an angle, so approach bolts from above and slightly from the driver side.
   ℹ️The housing may be sealed tightly with old gasket material. Do not pry against machined sealing surfaces.
   Torque spec

   Housing Bolts17 Nm (13 lb-ft)
5. 5

   Remove thermostat housing
   Carefully pull the thermostat housing away from the engine block. If stuck, gently twist the housing to break the gasket seal. Once removed, tip the housing to drain any remaining coolant into the drain pan. Remove the thermostat from the housing or engine block (depending on design).
6. 6

   Clean mating surfaces
   Thoroughly clean both the engine block mating surface and the thermostat housing sealing surface using a gasket scraper or plastic pick. Remove all old gasket material and residue. Wipe surfaces clean with a shop towel. Ensure no debris falls into the engine coolant passages.
   ⚠Do not use metal scrapers that could gouge the aluminum sealing surfaces. Scratches or gouges will cause coolant leaks.
7. 7

   Install new thermostat
   Position the new thermostat into the recess in the engine block with the spring side facing into the engine (toward the block). Ensure the thermostat is seated properly in its recess and the alignment tab (if equipped) is correctly positioned. The thermostat should sit flush and not rock.
8. 8

   Install new thermostat housing
   Install the new O-ring or gasket onto the thermostat housing (or onto the engine block, depending on design). Lightly lubricate the O-ring with clean coolant. Carefully align the thermostat housing over the thermostat and press it into place, ensuring the gasket remains properly positioned.
9. 9

   Install and torque housing bolts
   Install all three thermostat housing bolts hand-tight, ensuring the housing is seated evenly against the block. Using a torque wrench, tighten the bolts to specification in a crisscross pattern to ensure even gasket compression and prevent warping.
   ⚠Over-torquing aluminum housing can cause cracking. Use a calibrated torque wrench and do not exceed specification.
   Torque spec

   Housing Bolts17 Nm (13 lb-ft)
10. 10

    Reconnect coolant hoses
    Reconnect the coolant bypass hose to the bottom of the thermostat housing, ensuring it is fully seated. Position the clamp over the connection point and tighten to specification. Reconnect the upper radiator hose to the thermostat housing, ensuring it is fully seated, then position and secure the spring clamp or replace with a new worm-drive clamp.
    Torque spec

    Coolant Hose Clamps5 Nm (4 lb-ft)
11. 11

    Close drain plugs and refill coolant
    Close and torque the radiator drain plug and any engine block drain plugs to specification. Slowly fill the cooling system with Motorcraft Orange Coolant through the radiator cap or degas bottle until full. Fill the degas bottle to the cold fill line. Allow time for coolant to settle and add more as needed.
    Torque spec

    Coolant Drain Plug15 Nm (11 lb-ft)
12. 12

    Bleed cooling system
    With the radiator cap or degas bottle cap removed, start the engine and allow it to idle. Turn the heater to maximum heat and fan speed. As the engine warms and the thermostat opens, coolant level will drop. Continue adding coolant to maintain proper level. Run until engine reaches operating temperature and cooling fans cycle on. Squeeze upper radiator hose several times to help purge air bubbles.
    ⚠Keep hands clear of the engine-driven cooling fan. Monitor temperature gauge to ensure engine does not overheat during bleeding process.
13. 13

    Final fill and cap installation
    Once engine is at operating temperature and no more air bubbles are observed, shut off the engine. Allow to cool for 15 minutes, then top off coolant to the proper level in the degas bottle (to cold fill line). Install the degas bottle cap securely. Reconnect the negative battery cable and reinstall the engine cover.

Reassembly

1. Double-check all hose clamps are properly tightened and positioned
2. Verify all tools have been removed from the engine bay
3. Wipe down any coolant spills on engine components to prevent odors when engine heats up

Verification

• Start the engine and visually inspect the thermostat housing and all hose connections for coolant leaks
• Allow engine to reach full operating temperature and verify cooling fans cycle on properly
• Check coolant level in degas bottle after engine cools and top off if necessary
• Monitor coolant level and temperature gauge over the next several drive cycles
• Re-inspect for leaks after 50-100 miles of driving and check coolant level when cold

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