Radiator leak

i can’t find way to stop leak from radiator. I bought after market radiator and when my 1997 tahoe warms up it starts leaking from the cap. I tried replacing cap wih new one but it still keeps leaking from there like if its not sealing right. Any sugggestions?

How many miles on that 1997?

You are not going to like this, but I am suspecting an internal engine problem. Have someone use a sniffer to see if exhaust gases are getting into the cooling system.

It sounds like you just replaced the radiator? Check the filler neck on the radiator, maybe there is a lump of something that should not be there.

How much pressure is on the cap?

sounds like cooling system being overpressurized. Take Josephs advice and have it tested for blown head gasket.

i have 167000 miles on the tahoe and it does not overheat. if i drive it down to the store when i get back it starts leaking from cap, but like i said it is not even close to the half way mark on the temperature gauge