51 cub hydrallic shaft

[Tom Durrer]

51 cub hydrallic pump is leaking its fluid into
oil. Pull pump to replace O rings. The main drive
shaft of the pump has slight wear where its O ring
goes. Does this mean I need a new pump? Or is there
another way to fix. Hate to re-inst it, if this
wear is causing the leak and not a worn O ring.
Tom

 

[john *.?-!.* cub owner]

I have good luck using Dremel Abrasive buffs to go around and around the shaft smoothing it. It can stand having a little groove so long as it is smooth

also you can get double seal O-rings from McMaster.com, which let them ride outside the groove, but they are a real pain to install in the channel in the pump and be flat all the way around.
http://www.mcmaster.com/#o-rings/=s4kht4