What this test is for
Support leak localization after an overheating or coolant-loss symptom when a pressure test is appropriate for the vehicle and equipment.
Use the procedure to narrow a cause group. The result must be interpreted against the exact vehicle, equipment, and conditions.
- 01PurposeSupport leak localization after an overheating or coolant-loss symptom when a pressure test is appropriate for the vehic
- 02PrepareCompatible cooling-system pressure tester / Inspection light
- 03MeasureCool and inspect first / Apply controlled pressure
- 04InterpretA wrong adapter or a hot system can create injury or a misleading result.
- 05ContinueCooling-system temperature and airflow checks / Combustion-gas test
Follow the sequence, stop when evidence changes the path, and verify the exact vehicle information before acting.
Preserve the operating conditions, equipment setup, and result before moving to the next branch.
Tools and preparation
- Compatible cooling-system pressure tester
- Inspection light
- Exact cap/test information
- Approved coolant-handling equipment
Procedure and interpretation
Cool and inspect first
Let the system cool, inspect the cap/adapter area, and record level, visible leakage, steam, and recent service.
The system is safe to access and the correct adapter is identified.
A wrong adapter or a hot system can create injury or a misleading result.
Apply controlled pressure
Use the approved tester and do not exceed the vehicle or cap limit.
The pressure behavior is stable within the applicable procedure.
Pressure loss supports a leak path but does not by itself identify internal versus external leakage.
Inspect systematically
Look at hoses, radiator, pump area, thermostat housing, heater circuit, reservoir, and engine surfaces while preserving evidence.
A trace, wet area, odor, or pressure behavior can be correlated to a location.
No visible leak does not prove no internal loss; use the next appropriate test.
Record this test result
Save a bounded result and note to the selected vehicle. This is a personal record, not a verified diagnosis.
Choose a vehicle in My Garage or the vehicle selector first. IAR will not attach a test result to an unknown vehicle.
What to test next
Safety boundary
Only test a cool system
Never remove a pressure cap from a hot system. Use only the tester, adapter, pressure, and time limits specified for the vehicle.