easiest way is to fill radiator and look and see where fluid is coming out, but Im sure you thought of that. The best way is to plug the ends of the radiator up with some type of rubber stopper then insert blow air through the drainport while holding it under water. Wherever the bubbles are coming from is where its leaking.
Find where the fluid is coming out and repair/replace it.
red fluid is transmission fluid and could be leaking from several locations around the transmission. Check the cooler lines where they go into the radiator, the seals where the axles go into the transmission, but most likely is a leaking pan gasket, etc. The only good way to find it is to look under the van and see where the wet spot is located
It could be water pump, leaky radiator, hoses, head gasket, or just about anywhere else that the coolant circulates. You'll need to get under and find out where it's leaking.
A bad radiator is a radiator that is leaking or clogged. If you are loosing coolant then you have a leak that should be easy to find if the leak is at the radiator. If it is clogged your engine will overheat.
If your radiator is leaking then you will need to replace it. Additionally, if you find that your car is constantly running hot you will need a new radiator.
Call Around; Find A Radiator Shop or A Mechanic That Can Pressure Test Your Radiator. This Should Help
The only way to find out is to have a look it could be anything.
You really have to just find out where it is leaking and what it will take to repair it. GoodluckJoe
Check the wheel cylinders - they may be leaking and you can't see it on the outside of the wheel
Find the source and repair it.
Try to find out where it's coming from. Often coolant will leak down the front of the water pump, under the pulley. Even if you don't see the coolant, look for the mineral trace of the water. By the time you notice a leaky water pump it has usually been leaking for a while and has left a noticeable trail. If you don't notice coolant leaking there, check other places, freeze plugs, the sides of the radiator, radiator and heater hoses... Again, the coolant and water minerals typically leave a nice bright trace to tell you where it's leaking. If the radiator is leaking, don't try to fix it yourself and certainly don't put stop leak or any other chemicals in it. Either replace the radiator or take it to a radiator shop and have THEM repair it properly.
if car is leaking fluid , it has a leak a leak and steaming indicates it is engine coolant and the engine is over heating find the leak and fix it before your trash your engine