This is only necessary if you have parts of the engine that are "above" the filler cap. Mostly if they have such a problem it is at the thermostat housing and again mostly they will have a bleed screw on the housing if bleeding is required.
Having said that, mostly the exhaust heat exchanger (which is mostly where the filler cap is located) is the higest point and the "burping" will happen by itself. All you really need to do is check the coolant after a while of running (don't open it while hot) and top it up.
Sorry about the repeated "mostly" but without knowing what engine etc. you have it's difficult to be specific.
Having said that, mostly the exhaust heat exchanger (which is mostly where the filler cap is located) is the higest point and the "burping" will happen by itself. All you really need to do is check the coolant after a while of running (don't open it while hot) and top it up.
Sorry about the repeated "mostly" but without knowing what engine etc. you have it's difficult to be specific.
