# John Deere riding mower hydrostatic transmission stopped working

**URL:** <https://boards.straightdope.com/t/john-deere-riding-mower-hydrostatic-transmission-stopped-working/841163>\
**Category:** Factual Questions\
**Created:** [October 2, 2019, 5:27pm UTC](https://boards.straightdope.com/t/john-deere-riding-mower-hydrostatic-transmission-stopped-working/841163 "2019-10-02T17:27:02Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![dougrb](https://avatars.discourse-cdn.com/v4/letter/d/76d3ee/32.png) [@dougrb](https://boards.straightdope.com/u/dougrb)\
**Post date:** [October 2, 2019, 5:27pm UTC](https://boards.straightdope.com/t/john-deere-riding-mower-hydrostatic-transmission-stopped-working/841163/1 "2019-10-02T17:27:02Z")

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Model GT225. About 10 minutes into mowing I came to a standstill. Checked transmission fluid and it was very low. Bought some and filled it, still nothing and the fwd/rvr pedals are “mushy”. Both pedals also slightly depress when I move the cruise control lever forward. Any ideas on what I may have screwed up?

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**Author:** ![casdave](https://avatars.discourse-cdn.com/v4/letter/c/c6cbf5/32.png) [@casdave](https://boards.straightdope.com/u/casdave)\
**Post date:** [October 2, 2019, 5:57pm UTC](https://boards.straightdope.com/t/john-deere-riding-mower-hydrostatic-transmission-stopped-working/841163/2 "2019-10-02T17:57:02Z")

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I expect there is air in the system, the manual should offer some sort of solution, you need to look for something that relates to purging air out of the hydro system.

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**Author:** ![rat\_avatar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rat_avatar/32/255_2.png) [@rat\_avatar](https://boards.straightdope.com/u/rat_avatar)\
**Post date:** [October 2, 2019, 6:06pm UTC](https://boards.straightdope.com/t/john-deere-riding-mower-hydrostatic-transmission-stopped-working/841163/3 "2019-10-02T18:06:01Z")

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You most likely need to purge the hydrostatic system.

You will need to put it on jack stands and then open and close the bypass valve while switching between forward and reverse. Start at a slow engine speed and work up until it is clearly purged.