JOHN DEERE HYDRAULIC PUMP REPAIR KIT. 4320 4520 5020 WITH 50 CM3 MODEL GA1 PUMP. The item "JOHN DEERE HYDRAULIC PUMP REPAIR KIT. 4320 4520 5020 50 CM3 MODEL GA1 PUMP" is in sale since Friday, November 23, 2018.This item is in the category "Business & Industrial\Heavy Equipment, Parts & Attachments\Heavy Equipment Parts & Accessories\Antique & Vintage Equipment Parts". The seller is "islandmachinery" and is located in Aquebogue, New York. This item can be shipped worldwide.