Coolant Expansion Tank Cap Pressure Test

COOLANT EXPANSION TANK CAP PRESSURE TEST

WARNING: Never remove the coolant expansion tank cap under any circumstances while the engine is operating. Failure to follow these instructions may result in damage to the cooling system or engine and may cause personal injury. To avoid having scalding hot water or steam blow out of the cooling system, use extreme care when removing the coolant expansion tank cap from a hot cooling system. Wait until the engine has cooled, then wrap a thick cloth around the coolant expansion tank 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 the coolant expansion tank cap. Failure to follow these instructions may result in personal injury.





1. Carefully remove the coolant expansion tank cap from the coolant expansion tank to release pressure in the cooling system. Add coolant to the coolant expansion tank as necessary.
2. Use water to clean the area of the rubber seal and pressure relief valve. Install the cooling system pressure tester and adapter and immerse the coolant expansion tank pressure cap in water.

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 the cooling system pressure by turning the pressure release screw on the cooling system pressure tester. Tighten the pressure release screw and repeat step 3 at least twice to make sure the pressure test reading is repeatable and within acceptable gauge reading limits of the coolant expansion tank cap.
5. If the pressure test gauge readings are not within acceptable gauge reading limits, INSTALL a new coolant expansion tank cap.