I bought a used Craftsman riding mower # 917273220 a few weeks ago from a dealer. Since then, I have replaced the drive belt 5 times... it keeps getting chewed up. I have now noticed, that hydraulic fluid is dripping on the belt, and is probably the reason, they keep slipping off and getting chewed up. Where do I start? I don't have the money, to take it back in, and have it worked on... I have to figure this out, myself. Thanks!

Well I would certainly attempt to return it as defective. The only place for hydraulic fluid to leak from would be the trans axel and a replacement does not appear to be available and if you find one it will certainly be expensive.
As for belts are you using the original equipment?