Good question. Initially most connections to the engine except the large hose behind the waterpump with main failure behind the thermo hosing and leaking from radiator cap,tap and from overflow bottle cap as well. Leaking now from overflow bottle with new leak in large hose behind the waterpump thought this was only an issue at higher revs. Last week was in the country with some hills at say max 5000rpm on freeway plus city driving a few days now I notice a leak back of thermo housing from the small pipe going to the air intake. So air currently getting in but mostly bleeding through the overflow bottle cap. None of the hoses that have been replaced are leaking.