Coolant System Pressure Test
WARNING: This page is about a different car, the 2016 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
Always allow the engine to cool before opening the cooling system. Do not unscrew the coolant pressure relief cap when the engine is operating or the cooling system is hot. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. Failure to follow these instructions may result in serious personal injury.
NOTE:
Vehicles have a pressure relief cap on the degas bottle and no radiator cap.
- 3.
Remove the degas bottle cap. Inspect the degas bottle cap and degas bottle for any issues that would cause improper sealing, such as for cross-threading, burrs, damaged o-ring, etc. If any issues are found, INSTALL a new cap and/or degas bottle.
- 4.
Attach the Pressure Tester and adaptor (Snap-On TA53 or equivalent), to the degas bottle cap. The cap must hold pressure of 110 kPa +/- 21 kPa (16 PSI +/- 3 PSI). If any issues are found, INSTALL a new cap.
- 5.
Attach the Pressure Tester and adaptor (Snap-On TA52, AST ASSFZ-47, Redline RDL95-0750 or equivalent) to the degas bottle.
- 6.NOTE: Do not pressurize the cooling system beyond the maximum pressure listed in the specifications table in this article, or cooling system components can be damaged.NOTE: If the plunger of the pressure tester is pressed too fast, an erroneous pressure reading will result.
To pressurize the engine cooling system, slowly press the plunger of the pressure test pump and increase the pressure to between 97 - 110 kPa (14 - 16 PSI). Observe the gauge reading for approximately 2 minutes. Pressure should not drop during this time. If the pressure drops within this time, inspect for leaks and repair as necessary.
- 7.
If no leaks are found and the pressure drops, the leak may be internal to the radiator transmission cooler. Inspect the coolant for transmission fluid and the transmission fluid for coolant. Repair as necessary.
- 8.
If there is no contamination of the coolant or transmission fluid, the leak may be internal to the engine. Inspect the coolant for engine oil and the engine oil for coolant. Refer to Engine System General Information to diagnose the engine.