TC40DA hydraulics not working but hydrostat is

[gretchen8]

Ok, long shot but here it goes. My dad bought this tractor new and it has sat outside from his estate and I recently got it, but none of the hydraulics are working, which include the 3 pt hitch, front loader, or the pto. The hydorstatic drive is functioning, but nothing else is. ANY IDEAS???? New Holland dealer says it doesn't make since because the hydrostatic drive is working, but it could be a stuck valve, but of course several hundred dollars later to check it out. The bucket will occationally move for only a split second and stop, but not very often. All filters look good, but the hydraulic filter is only 1/2 full of oil and there is no water in the fluid----not miliky and it is full. The tractor has 500 hours on it. The amber lights are not working either. Any suggestions are greatly appreciated.

 

[6sunset6]

First things first unplug and replug the 4 quick disconnects on the loader.
Then report back. The hydrostatic drive is a separate pump from the loader and 3 point.
The PTO is not hydraulic but I think that machine has a hydraulic clutch . Could be anything. Stored outside could be fuses . I would plug and unplug all the fuses and see if the lights work. Stored outside and not run for a while things get cranky.

 

[J_J]

I am thinking you have lost the prime. Keep trying to prime it, but if not, try adding some air to the tank and see if that will help the pump prime itself.

If you install a gage at the IN port to the FEL, you will know id the pump is pumping and building pressure. If the engine is running and the pump is running, and if you have good suction, then you should be pumping fluid.

Just hold the joystick levers back for a while , and if you get fluid, put all cyl through several cycle to expel any air.

Work the 3pt lever also.

 

[gretchen8]

Ok, I unplug the coupling and you can hear the pump turning and it makes a noise as it turns, and the bucket will go up when it rotates, but it is not a steady lift. It's almost like it has lost prime. I backed out the Allen head on the side but didn't notice any air coming out.

 

[J_J]

I am not sure I follow you. 6sunset6 said to unplug and then re-plug the QD's. This may not fix things, but a QD not connecting correctly has happen before. Don't run the pump with the QD's unplugged.

Any air in the hyd system should be expelled by cycling all the levers on the tractor.

What allen head on the side. What was that ?

Have you checked the suction hose? Did you add air to the hyd tank to see if the pump will prime?

A quick way to tell f the ppup is pumping is to remove the hose from the IN port of the FEL valve and put in bucket. Crank the engine to running and observe the fluid flow that is supposed to come out of the pump hose. If lots of fluid, shut the engine off quickly.

If no fluid is coming out the hose, then your pump is not primed or the pump is bad, or the suction hose is blocked.

You said the pump was making noise, so it must be turning.

I would not you have you do this, but I would put a vacuum on the hyd tank, remove the suction hose at the pump, and get a 3 ft piece of hose and connect to the IN port of the pump, and fill with hyd fluid and holding the hose vertical, and start the engine, If that pump is good, it should suck in all that fluid in the hose real quick.

If the pump does suck in the fluid, the pump should be ready to go.

Some pictures would be good.

 

[gretchen8]

I disconnected and reconnected all 4 couplings. The bucket and 3 point hitch is now working, but not good. You can hear the pump turning, but it doesn't have constant pressure. It will rotate half a turn and then the bucket will barely move and then rotate another half a turn and then the bucket stops, and the another half turn it will move again. It sounds like it is not primed. When you say put a vacuum in the hydraulic tank, are you talking about on the back where you would add fluid? If I can get it primed, it should fix it. The Allen bolt is in the side of the hydraulic pump, which is the part that is making the noise. I'm assuming it was the hydraulic pump, which is on the right side under the platform.

 

[J_J]

The vacuum on the tank idea was to see if the tank is blocked or the suction hose is faulty.

What do you mean the pump is turnig and then stops?

Check the shaft on the pump to see if it is sheared off. If the pump is not turning continuously, then the shaft is sheared. It should be a constant running gear pump.

I am assuming the allen bolt is for bleeding the pump.

 

[k0ua]

I bet a dollar the allen head bolt he is refering to is on the hydraulic distribution block and I think it gives access to the relief spring/shims.
the pump is up on the engine. Some pix would sure help.

James K0UA

 

[gretchen8]

The pump turns constantly but you can hear it change sounds when the bucket starts moving and then when the noise changes, the bucket stops moving. I will send a picture if the part where the Allen head is. I don't know a lot about tractors, but this one has consumed me.

 

[wdchyd]

This could be a long shot, but somewhere a few guys had troubles with a set screw unscrewing inside the FEL control valve rendering all the hyds to by-pass back to tank ......


Tried searching but don't remember who/when this thread started about this situation.....

Maybe I'm way off track cuz I don't remember the exact symptoms :anyone:

Edit: sorry, I now see he disconnected/reconnected QC's and the 3ph and bucket now working.....Cancel that thought....