Tractor Repair: kubota hydrastatic drive., rotation direction, hydrostatic drive

Question
I have a b7200, I replaced the hydraulic pump due to hydraulic oil migration into the engine. now my hydrostatic drive scretches. I took a look inside the oil filter on the HST and it looks imploded.

Did I do something wrong while installing the pump to cause my HST to go out?

Why would the filter be imploded?

Do you think the HST is out?

Can a HST be rebuilt, or should I buy new?

Answer
I don't think you did any thing wrong -- Are you sure you have the correct pump -- check the out put volume - rotation direction ---- A filter will implode when the fluid is pushed the wrong direction or it is severly plugged up.  Check these items before you go any further --- the HST unit can be rebuilt but I don't think that is your problem.