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Jim J

hydro lift very very slow

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Jim J

I put hydro lift on my 7116 it works but it  is extremely slow, I went over everything, changed and checked the valves on the  hydro unit. Not sure what to check next, everything looks correct. What should I look for? Any help would be appreciated





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Welcome Jim

Not really into these lifts but seems most times during winter they get moisture in the oil and tend to freeze up, I assume you've got new oil in it so may not be your problem

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Did you top of the hydro fluid in the tranny after installing the hydro lift system?  If not, there could be air in the hydro lift lines that is compressing and slowing operation.  

As to topping off the fluid, it's supposed to be "full" when the level is at the top of the fill pipe at the back of the tractor.  If you have any bleed down in the hydro system, the fluid will always be at the top of the pipe, and possibly overflowing.  To ensure a full charge after having the tractor run for at least a few minutes so that the fluid is warm, I'll make sure the hydrolift cylinder is extended, and with the engine idling, I'll check the fluid level.  

If it's not low fluid level/air, then either the RVs or manual "freewheel" check valves are passing or the charge pump isn't pumping enough fluid.  The charge pump doesn't need to add much fluid to the tranny motor circuit, just enough to make up for internal losses.  The hydro lift requires much more flow.  Did you check the pressures?  See this post:



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Jim J

I figured it out with PhanDads help. I noticed in parts catalog that the rear line on the hydro is going to front fitting on the valve which says in on it . This is incorrect. The catalog has it backwards. This is how I had it connected.

The correct way is the following.

The rear port of the pump is the return; the front port is the supply.

The front port of the control valve is the supply; the rear port is the return


It should be front to front & rear to rear.



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