This procedure tests the cooling system for leaks using a pressure tester to identify faulty components such as radiator, hoses, water pump, or head gasket issues.

Warnings

Tools required

Parts

• Motorcraft Orange Coolant (if topping off) × 1 — VC-3DIL-B

Preparation

1. Ensure engine is completely cold to the touch (minimum 2 hours after last operation)
2. Park vehicle on level surface and engage parking brake
3. Verify cooling system is filled to proper level in degas bottle (between MIN and MAX marks)
4. Visually inspect all accessible hoses, clamps, and radiator for obvious damage or wetness before testing
5. Gather inspection tools and pressure tester with appropriate Ford radiator cap adapter

Procedure

1. 1

   Access and remove radiator cap
   Locate the degas bottle on the passenger side of the engine bay near the firewall. Slowly turn the cap counterclockwise to the first detent and allow any residual pressure to release. Once pressure is released, press down and continue turning counterclockwise to fully remove the cap. Inspect the cap gasket for wear, cracks, or deformation.
2. 2

   Check coolant level and condition
   Verify coolant is visible in the degas bottle and at proper level. Inspect coolant for proper orange color. Look for signs of contamination including oil (milky appearance), rust particles, or excessive debris. If coolant level is low, top off with Motorcraft Orange Coolant before proceeding. Coolant should be clear orange, not brown or muddy.
3. 3

   Install pressure tester adapter
   Select the appropriate adapter from your pressure tester kit that matches the Ford degas bottle cap threads and size. Thread the adapter onto the degas bottle opening hand-tight, ensuring it seats properly on the gasket surface. Verify the adapter is secure and seated evenly to prevent false readings from adapter leakage.
4. 4

   Attach pressure tester
   Connect the pressure tester pump assembly to the installed adapter. Ensure the connection is secure and the tester gauge reads 0 PSI before beginning. If the gauge shows pressure with engine cold and not yet pumped, there may be a cooling system issue or faulty gauge.
5. 5

   Pressurize cooling system
   Slowly pump the pressure tester to build pressure in the cooling system. Monitor the gauge and stop when reaching 16 PSI (typical operating pressure for this system). Do not exceed 18 PSI maximum. The system should hold pressure; if pressure builds unusually fast or won't build, check adapter installation and tester connections.
6. 6

   Initial pressure hold test
   Once at 16 PSI, stop pumping and observe the gauge for 2 minutes without moving or disturbing the vehicle. A healthy system should hold pressure with minimal drop (less than 2 PSI over 2 minutes is acceptable). Note the exact pressure reading after this initial hold period. A rapid pressure drop indicates a significant leak.
7. 7

   Inspect engine bay components
   With system pressurized at 16 PSI, systematically inspect all cooling system components in the engine bay. Check both upper and lower radiator hoses, heater hoses at firewall connections, thermostat housing (located at front of engine), water pump area (front of engine between cylinder banks), and all hose clamps for wetness or dripping. Use flashlight to inspect underside of hoses and fittings. Pay special attention to the turbocharger coolant lines on both banks.
8. 8

   Inspect radiator and condenser
   Examine the radiator core, tanks, and end caps for seepage or wetness. Check the plastic tank seams where they join the aluminum core. Inspect the transmission cooler lines at radiator connections (if equipped with automatic transmission). Look for coolant weeping from the radiator drain petcock. Check the charge air cooler (CAC) mounted in front of radiator for coolant evidence.
9. 9

   Inspect under vehicle
   Move underneath the vehicle while maintaining system pressure. Inspect the water pump weep hole (small hole at bottom of pump housing between cylinder banks), engine block freeze plugs on both sides of engine, and lower radiator hose connections. Check the oil pan area and exhaust manifolds for coolant drips which could indicate head gasket issues. Look for coolant trails or staining patterns.
10. 10

    Check for internal leaks
    With pressure still applied, remove the engine oil dipstick and inspect for coolant contamination or pressure escaping from dipstick tube. Check oil cap for milky residue. If equipped, inspect the oil catch can or PCV system for coolant presence. On the 3.5L EcoBoost, internal leaks may show as coolant in the intercooler system or oil in the degas bottle.
11. 11

    Monitor pressure retention
    After completing visual inspection (approximately 10-15 minutes total), observe the final pressure reading on the gauge. The system should still maintain at least 12-14 PSI from the original 16 PSI. Record the final pressure. A loss of more than 4 PSI over 15 minutes indicates a leak that requires further diagnosis.
12. 12

    Release pressure and remove tester
    Slowly release pressure from the system using the tester's pressure release valve. Once gauge reads 0 PSI, disconnect the pressure tester from the adapter. Remove the adapter from the degas bottle. Reinstall the original radiator cap by pressing down and turning clockwise until it clicks into the locked position.

Reassembly

1. Ensure degas bottle cap is properly installed and locked in place
2. If coolant was added, verify level is between MIN and MAX marks on degas bottle when cold
3. Clean any spilled coolant from engine bay components to prevent future confusion during leak diagnosis
4. Document all findings including pressure readings and any leak locations identified

Verification

• Confirm cooling system held at least 12 PSI for 15 minutes during test, indicating no major leaks
• Verify degas bottle cap is secure and properly seated
• If leaks were found, mark their locations and plan repairs accordingly
• For systems that failed pressure test, identify specific failed component (hose, radiator, water pump, head gasket) before proceeding with repairs
• If system passed pressure test but overheating issues persist, investigate thermostat, water pump flow, or airflow issues separately

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