Radiator Cap
| 1 - PRESSURE CAP |
| 2 - TYPICAL COOLING SYSTEM PRESSURE TESTER |
Remove the cap from the radiator. Be sure that the sealing surfaces are clean. Moisten the rubber gasket with water and install the cap on the pressure tester (special tool #7700, Tester, Cooling System) or an equivalent. Refer to Fig 1.
Operate the tester pump to bring the pressure to 104 kPa (15 psi) on the gauge. If the pressure cap fails to hold pressure of at least 97 kPa (14 psi) replace the cap. Refer to the following CAUTION .
The pressure cap may test properly while positioned on tool (special tool #7700, Tester, Cooling System) (or equivalent). It may not hold pressure or vacuum when installed on the radiator. If so, inspect the radiator filler neck and radiator cap's top gasket for damage. Also inspect for dirt or distortion that may prevent the cap from sealing properly.
Radiator pressure testing tools are very sensitive to small air leaks which will not cause cooling system problems. A pressure cap that does not have a history of coolant loss should not be replaced just because it leaks slowly when tested with this tool. Add water to tool. Turn tool upside down and recheck pressure cap to confirm that cap needs replacement.