Does anyone have a diagram of the oil cooler gasket location? on 1998 Mercedes-Benz ML320

I have a bad oil leak on the driver side of the engine. Already replaced the cam cover gasket. Oil seems to be coming from behind that area. Someone mentioned an "O" ring between the oil cooler and oil filter housing. Where is this "O" ring?

Asked by for the 1998 Mercedes-Benz ML320
oil cooler gasket location?