Pressure Tester Method
The engine should be at normal operating temperature. Recheck the system cold if cause of coolant loss is not located during the warm engine examination.
Hot, pressurized coolant can cause injury by scalding.
Carefully remove the radiator pressure cap and check the coolant level. Wipe the inside of the filler neck and examine the lower inside sealing seat for nicks, cracks, paint, dirt and residue. Inspect the coolant hoses for internal obstructions. Insert a wire through the hose to be sure it is not obstructed.
Inspect the outside of the filler neck. If damaged, seating of the pressure cap valve and tester seal will be affected.
Attach the SVT275 cooling pressure tester (1) available from Mopar® Service Equipment, or an equivalent pressure tester to the pressurized coolant bottle (2).
Operate tester pump to apply 103.4 kPa (15 psi) pressure to system. If hoses enlarge excessively or bulges while testing, replace as necessary. Observe gauge pointer and determine condition of cooling system according to following criteria:
Holds Steady: If pointer remains steady for two minutes, serious coolant leaks are not present in system. However, there could be an internal leak that does not appear with normal system test pressure. If it is certain that coolant is being lost and leaks cannot be detected, inspect for interior leakage or perform Internal Leakage Test.
Drops Slowly: Indicates a small leak or seepage is occurring. Examine all connections for seepage or slight leakage with a flashlight. Inspect radiator, hoses, gasket edges and heater. Seal small leak holes with a Sealer Lubricant (or equivalent). Repair leak holes and inspect system again with pressure applied.
Drops Quickly: Indicates that serious leakage is occurring. Examine system for external leakage. If leaks are not visible, inspect for internal leakage.