Radiator Cap: Testing and Inspection

PRESSURE RELIEF CAP PRESSURE TEST
1. Remove pressure relief cap from the radiator coolant recovery reservoir filler neck.

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

Rotunda Radiator/Heater Core Pressure Tester 014-R1052:

2. Use water to clean the pressure relief cap in the area of the rubber seal and the vacuum relief valve. Immerse the pressure relief cap in water and install on the shallow filler neck of the Rotunda Radiator/Heater Core Pressure Tester 014-R1052 and Rotunda Radiator Cap Adapter Set 014-R1065 or equivalent.

NOTE: The adapter is designed to accept both deep and shallow neck pressure relief caps.

3. Immerse the filler neck seal in water and install in the filler neck adapter.

NOTE: The filler neck adapter is reversible so that it may be used on either a deep or shallow filler neck. It will also fit either end of the pressure relief cap pressure test adapter.

4. Install the filler neck adapter with filler neck seal on the deep filler neck end to the pressure relief cap pressure test adapter.
5. Connect the female quick connect fitting of the pressure test pump to the male quick connect fitting of the filler neck adapter.
6. Slowly depress the plunger of the pressure test pump until the pressure gauge reading stops increasing and note the highest pressure reading obtained.

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

7. Release the pressure by turning the pressure relief screw counterclockwise. Then tighten the pressure relief screw and repeat Step 6 (at least twice) to ensure the pressure test reading is repeatable within the acceptable gauge reading limits of the pressure relief cap and is not erratic.
8. If the pressure test gauge readings are not within the acceptable gauge reading limits, replace the pressure relief cap. If the pressure test gauge readings are within the acceptable gauge reading limits, perform pressure test of the cooling system as outlined under Pressure Test at Inspection and Verification.