well,for starters if its not broke dont fix it,if you suspect a leak,there is a pressure test system you can use,you may be able to rent one from your local autoparts store,its a pump that fits over the neck of the coolant bottle,you pump up the pressure then let it sit,as long as it holds pressure after 30 mins,your leak free,if you disconect the upper radiator hoses/hose peak inside,look at the aluminum fins,they should look whitish/grey,if you notice allot of scally build up on the fins,you may want to drain the system add a bottle of coolant flush,fill it with water,then run it for about 10 mins at operating temp up dpwn the highway,then drain coolant system rinse,then refill with a 50/50 mix.its just a generall inspection that can tell you allot,also if you have very high mileage,over 100k,goodluck!!