transmission fluid backing up in my radiator or maybe its oil 2000 astro
oil could slip thru or under a head gasket. but not trans. fluid
The astro is famuse for head gasket problems
The oil in the head is not pressurized since it is not an overhead cam engine the only place where oil pressure will overcome and enter the cooling system without getting lots of coolant in the oil is in the radiator where the oil cooler is there is also sometimes a trans cooler on the passenger side of the radiator and since it's a van I would bet there is a trans cooler on the radiator. it is not a head gasket unless the coolant is running into the crankcase.
check your oil and see if it is a milky color like chocolet milk
It will look more like a vanilla cookie or yellow cake rather than chocolate milk.
Looking for a Used Astro in your area?
CarGurus has 251 nationwide Astro listings starting at $995.
Search Chevrolet Astro Questions
Chevrolet Astro Experts