You sure it isn't your belt squealing? Having a little antifreeze leak out isnt necessarily indicative of a problem - if could have just leaked out the overflow after running warmer than usual - it is spring, after all.
The most common cause of sleds squealing is the belt riding too high in the secondary, which causes excessive tension on the belt at idle and results in a squeal. Make sure that it isn't coming from the belt before you assume the worse. Take off the belt and see if the noise persists. If it is the belt, there are three bolts in the back of the secondary clutch - you can adjust the belt lower in the secondary by removing washers from under these bolts. You probably don't want to completely remove them, but just reduce them with ones half as thick. Check home depot for washers before your yam dealer -- cheaper.
Also, don't take my word for where the antifreeze is coming from, it CAN be from a seal, or from a damaged heat exchanger. But to note, lots of people, including myself, have seen antifreeze under the sled on warm days.
