Radiator Cap

WARNING: NEVER REMOVE THE RADIATOR 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 RADIATOR, USE EXTREME CARE WHEN REMOVING THE RADIATOR CAP FROM A HOT RADIATOR. 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 CERTAIN ALL THE PRESSURE HAS BEEN RELEASED, PRESS DOWN ON THE RADIATOR CAP (STILL WITH A CLOTH), TURN AND REMOVE.

1. Remove radiator cap from radiator filler neck.





2. Use water to clean radiator cap in area of rubber seal and vacuum relief valve. Immerse radiator cap in water and install radiator cap pressure test adapter from Rotunda Radiator/Heater Core Pressure Tester 014-R1052 or equivalent.

NOTE: The filler neck seal is reversible so it may be used on either end of radiator cap pressure test adapter.

3. Immerse filler neck seal in water and install in filler neck adapter. Then, install filler neck adapter with seal on open end of pressure tester adapter.
4. Connect female quick disconnect fitting of pressure test pump to male quick disconnect fitting of filler neck adapter.
5. SLOWLY depress plunger of pressure test pump until pressure gauge reading stops increasing and note highest pressure reading obtained.

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

6. Release pressure by turning pressure relief screw counterclockwise. Then, tighten pressure relief screw and repeat Step 5 (at least twice) to make sure pressure test reading is repeatable within acceptable gauge reading limits of radiator cap and is not erratic.
7. If pressure test gauge readings are not within acceptable gauge reading limits, replace radiator cap.