Radiator is loosing fluid. I tried to track it but didn't see it coming from radiator or hoses. it is also loosing fluid when it is cold. The Radiator didn't seem to have oil in it, could it be the water pump.
Very possible. Look around the neck of the water pump. There is a small weep hole there. If you see any signs of coolant around that hole the pump needs to be replaced. To find the leak I would do a pressure test on the cooling system. Sometimes it's easier to find the leaks this way because the coolant wont evaporate off the engine. I find a small inspection mirror very helpful in finding some leaks.
I just had to do all hoses cap & radiator but also my "Radiator Mount Bushings" ended up being the unknown leak source. $24.99 each at O'Reillys. good luck Mine is 96 4.3 blazer
Search Chevrolet Blazer Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Chevrolet Blazer Experts