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TerryM

Sundstrand hydro

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TerryM
I have a 712 hydro that works fine if you use it every day. But if it sits for more than a week,it has to run for a few minutes before the hydro will pull. The longer it sits without being used,the longer it has to warm up before it will move forward or reverse.Belt is tight,filter is new and fluid is full. It Acts like it's loosing its prime. Anyone have an idea what may cause this?

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powermax_paul
Check to make sure the pipe plugs on the top of the hydro unit aren't loose so that air can't bleed in. Also, check with Bill Klein at Sandy Lake Implement. He was a big help in troubleshooting my Sunstrand unit last week.

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Al
Hi, When you start it and put it in forward, does it do nothing and then suddenly lerch forward? I would suspect that you have a bad charge pump. It is replaceable from the outside on the left side. This has fixed every one I have had a problem with like this. Your best shot is to check the charge pump pressure first. This pump actually pressurizes the upper case, at about 275 lbs pressure. This forces the oil into the rotating group pistons when you shift the swashplate for forward and reverse and speed. It is also the pressure source for the power steering and the hydraulic lift. Need more info yell and I'll get it for you. Happy Holidays, Al

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