John Deere 555A hydraulic oil filling transmission housing

[Benzcrawler]

Hello all I have a John Deere 555A I fill the hydraulic reservoir to half way in the hydraulic reservoir sight glass, within 10 minutes of run time the hydraulic reservoir sight glass is not showing any level. The transmission housing dip stick level increases. Based on this I suspect that the hydraulic system pump that is mounted on the transmission housing is leaking into the transmission housing due to a failed shaft seal in the hydraulic oil pump. Please let me know if this is sound reasoning, or if there is some other component that could be allowing hydraulic oil to be flowing into the transmission case at an accelerated rate.

[Jim B]

Welcome to the Boards.

Hydraulic pump seal gone bad is the most likely scenario based on your description.

Just a bit of housekeeping on the Board. You thread about a 555A should be on the Late Models Board, which is for the 350 models and newer. This Early Models Board is for the 2010 crawlers and the models before that. A moderator will likely move your thread to the Late Models Board when they see it.