I am having a problem with my cooling water leaking out through but there's no external leakage could it be that there air in the system because I try to replace the thermostat but still leaking through the radiator cap if it get hot what could it be or what must I do again. its Chevrolet cruise 1.8 2011 model.
Take the time to fill it up with coolant, turn the heat on max, and bleed the air out of the system. A spill free funnel makes it easier.
The radiator cap could be bad. The cap is probably rated for 15 psi and if that went bad water could leak out.