It's been a long time since we had one of those around, but I believe they just have one hydraulic pump.  As I recall it is fairly simple as far as something like this goes.  I remember changing out the spyder (#11) on a 4386 at the end of a field one time.

From Case parts (start at http://www1.caseih.com/northamerica/PartsService/Pages/search.aspx )