Leak Testing - On-Vehicle
Tool Required, or equivalent: J24460-01 Cooling System TesterNOTE:
^ A very slight amount of seepage may occur at the water pump vent hole during vehicle operation. Traces of residue may OCCUR from the lower vent hole. The water pump should be replaced only if coolant is dripping from the vent hole while the engine is in operation or while the cooling system is pressurized.
^ Minor water pump seepage and minor engine cooling system leaks may be corrected by adding two engine coolant supplement pellets to the cooling system.
Two pellets should be added to the coolant system under the following conditions:
^ Vehicles encountering water pump seepage or minor coolant leak/loss that cannot be corrected through normal service procedures.
^ When cooling system is drained and coolant is replaced with new coolant due to engine repair work or at recommended coolant change intervals (5 years or 150,000 miles).
^ Whenever engine water pump is replaced. The addition of the pellets provides a mild lapping of the new water pump seal that improves conformability of the mating surfaces. Water pump seal seepage is minimized by the addition of these pellets.
^ Do not add pellets into nonpressurized coolant recovery bottles.
^ The two pellets should be installed into the radiator. Care should be used to avoid contamination of the pressure/radiator fill cap and mating sealing surfaces with pellet debris. The use of sealant pellets may cause a film to appear around the sides of nonpressurized coolant recovery reservoirs. The presence of this film is considered to be normal. Following installation of the pellets, run the engine for approximately 15 minutes, then check for coolant leaks and proper cooling system operation.
^ If pellets have been installed to correct an excessive water pump seal seepage condition, one to two weeks of normal vehicle operation may be required to lap in the mating seal surfaces. Some staining due to minor seepage may continue to occur. This is considered normal.
1. Ensure that radiator and heater hose clamps are properly positioned and secured.
2. Inspect connections for leaks. Repair as required.
3. Remove radiator fill cap.
4. Fill the cooling system to the "FULL COLD" mark.
5. Attach Cooling System Tester to radiator neck.
^ Follow instructions supplied with Cooling System Tester.
6. Build up pressure to no more than 138 kPa (20 psi).
7. System should hold pressure for about two minutes.
a. If a measurable amount of pressure drops in less than two minutes, check for leaks.
b. Leak may be internal or external. If no visible leak is found, including heater core, engine disassembly may be required. See Engine.