I googled the model and found a parts diagram in it. Generally hydro's are non serviceable, but in the pictures it appears to be an up market hydro with the reservoir tank. Just check it has oil in it. Also check for leaks etc.
Not impossible that it is a belt or tensioner etc. You can usually tell by how it sounds when you try to drive, if it make like a groaning sound it is most likely low on fluid or a stuffed transmission
