cat 236 coolong fan leaking

I've got a 2003 236 and the fan that cools the radiator is leaking oil . I was wondering if anyone has rebuilt one and if so is their anything to look out for. I think its a shaft seal the hoses are dry and the fittings are tight. Any info would be appreciated . Plus I have a exhaust leak that started. The flex pipe that comes off the manifold and goes to the muffler cracked. Its still the factory accordion style and looks to be stainless I was wondering if it would be worth trying to tig it up or would I be chasing cracks ? Has anyone tried it or is it waisting time since it has been heated up and cooled so many times ? Thanks in advance

cat 236 coolong fan leaking