Cooling System Pressure Test

WARNING: This page is about a different variant/trim than selected.

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

Switch the engine off
Open the hood and install protective fender covers
Carefully remove the coolant expansion tank pressure cap from the coolant expansion tank to relieve pressure in the cooling system. Add coolant to coolant expansion tank as necessary
Install the pressure tester equipment to the cooling system following manufacturers instructions. Reinstall the coolant expansion tank pressure cap (if pressure test equipment is not installed to the coolant expansion tank)
Pressurize the cooling system to the coolant expansion tank pressure cap lower limit
Observe the gauge reading for approximately two minutes. Pressure should not drop during this time
- If system holds pressure, continue from step 7
- If the pressure drops, check the complete cooling system for leaks. Also refer to engine system checks if a leak cannot be located in the cooling system. Correct any leaks found and recheck the system
Release the system pressure and remove the pressure test equipment. Check the coolant level. Replenish as necessary with the correct coolant solution
Check the radiator overflow hose for any obstructions which may block the flow of coolant either to or from the coolant expansion tank
Conduct the coolant expansion tank pressure cap pressure test in this article
COOLANT EXPANSION TANK PRESSURE CAP PRESSURE TEST

WARNING: Never, under any circumstances, remove the coolant expansion tank pressure cap while the engine is operating. To avoid having scalding hot water or steam blow out of the cooling system, use extreme care when removing the coolant expansion tank pressure cap from a hot cooling system. Wait until the engine has cooled, then wrap a thick cloth around the coolant expansion tank pressure cap and turn it slowly until the pressure begins to release, step back while the pressure is released from the system. When certain all the pressure has been released (still with a cloth) turn and remove the coolant expansion tank pressure cap. Failure to follow these instructions may result in damage to the cooling system, engine and/or cause personal injury.
Remove the expansion tank pressure cap from the coolant expansion tank
Use water to clean cap in area of rubber seal and vacuum relief valve. Following manufacturers instructions, install the coolant expansion tank pressure cap to the pressure tester
NOTE: If the pressure tester is pressurised too quickly, an erroneous pressure reading may result.
Slowly pressurise the system until the pressure gauge reading stops increasing, and note highest pressure reading obtained
Release pressure and repeat Step 3 at least twice to make sure the pressure test reading is repeatable and within specification
If the pressure test gauge readings are not within specification, install a new coolant expansion tank pressure cap