In this case, emit the pressure by loosening the thermostat cap. [title] Place a pan or bucket under the radiator plug beneath the car to catch the old antifreeze.
[header] How to install a coolant flush kit [title] Check the engine to make sure it is no longer hot. [step] Loosen the radiator cap to release any pressure still left, and then re-tighten. [substeps] Many newer cars have the cap on the coolant reservoir instead of the radiator itself, but, on certain cars, there may be no radiator cap at all.