Todd,I know it's not the case halves,I haven't had the saw apart & it didn't leak previously.It also can't be the oil cap because I had the saw on the clutch side when I filled it.It leaked on the clutch side somewhere which points to a missing gasket,or the pump body is cracked.I've got another pump here if the pump is shot.Now I gotta pull the freakin' pump again.There's nothing I klike better than pulling things apart 2 or 3 times.