coolant/antifreeze refill

i have a 92 sc2 dohc and im trying to replace the fluids after fixing a leak but i cant find the radiator cap. ive been filling it through the over flow tank. can any one help me as to where the cap is or to where i make find a nother opening to help the fluid flow through a lil better? thanx

the resovuior cap is the only cap, system is self bleeding, no other spots need to be filled.(but squeeze the upper radiator hose, that helps on a lot of cars.)

thanx thats exactly what i was doing. just makin sure i did it right