Coolant leaking from radiator cap

[Eska]

Hi, im new to this forum as well as to being an owner operator. I have a Freightliner cascadia with cummins cm2250. My problem is, coolant leaking from the radiator cap, i changed the cap with the new one and new one is leaking too. My engine is running 15-20 degrees hotter than usual and when it gets hot oil pressure drops. I dont know if it has anything to do with the last repairs but i changed the oil pan seal, crankcase breather filter. And right after this it started to having these problems. Any ideas or same experience?[/size]