mystery coolant leak
 

I have a 95 runner with the v6, auto trans. My problem is that I have a coolant leak somewhere but can not find the leak. If I park the vehicle over night there will somethimes be a small amount of coolant showing on the driveway in the am it is on the right front of the truck and appears to be dripping onto the skid plate before it hits the ground. I have looked all over and can not find the leak and it doesn't always mark it's spot. I am having to put in a quart of coolant about once evey 3-4 weeks. Any suggestions?

bottom of the radio cracked ? bad hose ? drain valve a little loose ?

That's what I thought and have checked all. I suspected the radiator, but can't find a leak

could be a leak cause by pressure