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Simplicity 5212.5 - Stuck hydro dump switch

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Hi Everyone,

I just got this Simplicity 5212.5 free off Craigslist and I'm trying to sort out an issue with the hydro. Currently it will not disengage and the tires just skid if I try to roll it with the engine off. The transmission engagement lever moves, but the dump valve plunger does not move at all.

Should this be easy to push in and out? I've tapped it with a hammer and it does not move. I don't want to hit it too hard though since it may break something. 

Any advice on how to fix this? Does this indicate something fixable or a dead hydro?






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ok that is an eaton hdrostatic  unit pressure wash the top and let it dry polish the shaft of the reilief valve with emery cloth soak  a scrap of cloth with blaster or liquid wrench  spray the shaft with same wrap cloth around the shaft  overnight use a 1/4 drive 6 point socket on the top of the shaft and try to turn back and forth  while  pushing down.  note there is an o ring seal in the valve body so dont use carb cleaner

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Thanks for the advice here.  I'm still working on it, but I'm pretty sure that the Dump Valve Shaft is rusted/frozen to the Dump Valve Guide.   After loosening the nut that is around the shaft, I can see that the shaft and stub of the guide that protrudes out will both spring in and out a bit when pushed, but the shaft does not move though the guide at all.   Per your advice, I've got it soaking in PB which hopefully will free things up eventually





Dump 2.JPG

Dump 1.JPG

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I got it free!  The trick was to loosen the nut in the pic above and use lots of Kranoil and let it soak.   Also things were made much easier by taking off the mower deck and the engagement lever. After a day of soaking, I put the nut back on tight and used my impact screw gun with a ratchet to dislodge the dump valve shaft.  I did this gently, with just two impacts in the loose direction and then two in the tight direction, repeat, repeat, repeat.   Gradually it loosened up.   

For anyone with a tractor like this, go put some lube on this thing.  You don't want it rusting!


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I used Kano to dislodge it, but for keeping it lubed I've just been hitting it periodically with spray PB, wd40, or whatever I have handy and the moving the lever a few times.  My guess is that never exercising the lever is what leads to this

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