yes air compressors are charged with oil (to help lubricate). You can add coolant with some oil included (see convert old freon to new type kits/ they have oil added) if you have leaked some out, but obviously this is a temporary fix...better to evacuate whole system, fix compressor leak, then fill with properly measured oil + coolant.
there is a transmission cooler inside your radiator and it must be leaking. probably replace the whole assembly
The better question is what is leaking transmission fluid?
Because your transmission has a seal that is leaking.
Valve cover gasket?
try the cool line fitting from the radiator to the transmission i just had that problem on a 1994 mercury Sometimes you can leak out of the tailhousing of your transmission if the housing seal is slightly damaged
The output shaft seal has failed and transmission fluid is leaking by, and that would explain the transmission fluid appearing there.
Rear main engine seal or front transmission seals
A 2000 Mercury Sable might have a vibration at low speeds after changing the transmission fluid because of a lack of fluid or leaking fluid. Check the transmission case for leakage and check the fluid level before driving again.
Perhaps water pump is leaking?
You need to check the transmission gasket between the transmission pan and the body. If it's leaking you have to replace it.
why do toyota sienna transmission leaking after change a new transmission and ran 5000 miles?
fluid is a lubricant of transmission