Radiator Cap: Testing and Inspection

WARNING: Never remove the radiator cap under any conditions while the engine is operating or when the cooling system is hot. Failure to follow these instructions could result in damage to the cooling system or engine or personal injury To avoid having scalding hot coolant or steam blow out of the radiator, use extreme care when removing the radiator cap. Wait until the engine has cooled, then wrap a thick cloth around the radiator cap and turn it slowly to the first stop, step back while the pressure is released from the cooling system. When the pressure has been released, press down on the radiator cap (still with a cloth), turn and remove it.

1. Remove the pressure relief cap from the radiator coolant recovery reservoir.
2. Use water to clean in area of rubber seal and vacuum relief valve. Immerse pressure relief cap in water and install pressure relief cap pressure test adapter from Pressure Tester on the pressure relief cap.

NOTE: If the plunger of the pump is depressed too quickly, an erroneous pressure reading will result.

3. Slowly depress the plunger of the pressure test pump until the pressure gauge reading stops increasing, and note highest pressure reading obtained.
4. Release pressure by turning pressure relief screw counterclockwise. Then tighten pressure relief screw and repeat Step 5 at least twice to ensure pressure test reading is repeatable within acceptable gauge reading limits of pressure relief cap and.
5. If pressure test gauge readings are not within acceptable gauge reading limits, replace the pressure relief cap.