# New Holland TN70 Hydraulics not working



## Blueskyhook (Apr 21, 2021)

I am working on a New Holland TN70 that the hydraulics are not working. The owner has installed a new filter and pump. I tried to bleed pump but it did not work. Drained oil out and checked lines and filter for obstruction but did not find any. Filled back up with oil and same problem. I can blow air into fill up hole and push oil to pump and the pump works. Its like it not getting enough oil from reservoir. I even took line loose on bottom of pump and no oil runs out.


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## Fedup (Feb 25, 2014)

Does the steering work? Why was the pump replaced to begin with?


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## Blueskyhook (Apr 21, 2021)

The steering works real slow. The owner replaced pump because three point lift and frontend loader was not working when he bought the tractor.


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## Fedup (Feb 25, 2014)

Without knowing much of the previous repair history here, my first guess would be in the direction of the O rings on the inlet tubes between the filter base and the pumps. They don't usually cause problems, but then again the front pump has been off at least once so the tube has been disturbed, and there are three O rings involved right there.I believe the suction elbow is mounted with allen head bolts, and there is a loader in the way so access to see and comfortably reach everything is somewhat limited. Typically replacement pumps don't come with inlet and outlet O rings or the mounting gasket. Those can easily be overlooked until the new pump comes out of the box and then it's "oh well, the old ones don't LOOK bad", so they aren't replaced.


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## Blueskyhook (Apr 21, 2021)

But shouldn't hydraulic oil be pouring out if you take feed line loose from pump and reservoir full?


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## Fedup (Feb 25, 2014)

You should get SOME oil there, but the oil level in the tractor is well below that(or at least it should be). The pump needs to pull the fluid up there and it doesn't sound like that's happening for whatever reason.


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## Choatecav (Jul 2, 2020)

I just replied to a thread I started last night on a very similar subject with the same type of tractor. Mr. Fedup knows his business as he nailed the problem and mine is working.

I will say that when we opened the valve on the front pump, we had to not only start it but also rev it up just a tad and jiggle the front lift lever. After just a bit, the fluid started to flow. Perhaps this model just need a bit more coaxing once the valve is opened.


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