JD 2850 Loss of Hydraulics

[Geovr]

I have n't hydraylics vibrating and all other works ok. I measured the low presure before 2 years and it was ok (I think near to 10 atm). I have this problem for 10 years and decided now to see what is happening. Hydraulic motor works only two times per yεar so the problem is not so big so that a change of pump or a general repair of the hydraulics is beneficial.
I'm only interested in knowing if any valves between the 2nd pump and the quick couplers reduce the output flow, so I would have to connect the hydraulic motor directly after the pumb.
Regards

 

[davidroberts30]

I have n't hydraylics vibrating and all other works ok. I measured the low presure before 2 years and it was ok (I think near to 10 atm). I have this problem for 10 years and decided now to see what is happening. Hydraulic motor works only two times per yεar so the problem is not so big so that a change of pump or a general repair of the hydraulics is beneficial.
I'm only interested in knowing if any valves between the 2nd pump and the quick couplers reduce the output flow, so I would have to connect the hydraulic motor directly after the pumb.
Regards

Does the spool lever travel full range??

 

[Cowabunga]

Flow reduction valves are usually fitted between the tractor and implement QR couplers on these tractors and will be visually obvious.

 

[Geovr]

Does the spool lever travel full range??

Yes. I also have connected a pair of quick couplers before the selective control valve. This way i operate the hydraylic motor from an external valve. I tried to bypass the external valve without better results.
I attach here a photo with the point that is connected the out line.

 

[Geovr]

Sorry but at the previous post i forgot to mark the line....

 

[Geovr]

Flow reduction valves are usually fitted between the tractor and implement QR couplers on these tractors and will be visually obvious.

Hi. What are the QR couplers?? how can i recognize them

Regards

 

[Geovr]

I am afraid if steering pressure control valve reduces the flow so to keep a stantard pressure for the steering

 

[Cowabunga]

Hi. What are the QR couplers?? how can i recognize them

Regards

You surely have quick release couplers, female on the tractor and male on your implement pipe ends?

 

[Geovr]

You surely have quick release couplers, female on the tractor and male on your implement pipe ends?

Yes...

 

[Tractortech]

Does the flow at the rear of the tractor get less when the Hi-Lo is shifted?? You will have better oil flow when the Hi-Lo is in the position it defaults to with the engine off.
If you put a 0-20 bar gauge in the low pressure test port above the high pressure pump, see if it has pressure when the oil is flowing at max. If the pressure drops to zero, the problem is in the transmission..

 

[Geovr]

Hi.
Tractor has n't Hi-Lo.
I"ll try the trick with gauge but later, now is cold and my garage has n't heating.
Also i am interesting to connect the Hydraulic motor direct before the steering pressure control valve because if valve has any problem then it don't opens full allowing all the oil to flow from it to couplers.
As i have read at service manual it opens when at input the oil has a pressure of 123bar, but if when i have full flow the pressure falls a bit than 123 bar then the valve is not full open and the flow is less.
Simple my opinion...

Regards

 

[davidroberts30]

Hi.
Tractor has n't Hi-Lo.
I"ll try the trick with gauge but later, now is cold and my garage has n't heating.
Also i am interesting to connect the Hydraulic motor direct before the steering pressure control valve because if valve has any problem then it don't opens full allowing all the oil to flow from it to couplers.
As i have read at service manual it opens when at input the oil has a pressure of 123bar, but if when i have full flow the pressure falls a bit than 123 bar then the valve is not full open and the flow is less.
Simple my opinion...

Regards

you sure the 1234 gear lever doesnt move sideways for high/low?

 

[Geovr]

you sure the 1234 gear lever doesnt move sideways for high/low?

Yesssss....
I own this tractor 32 years... so i believe that i know it!!

Regards

 

[Cowabunga]

Yesssss....
I own this tractor 32 years... so i believe that i know it!!

Regards

I’ve yet to see a 2850 with SG2 cab that does not have HiLo [Power Synchron] in the UK. I didn’t know they made them so basic.

 

[Geovr]

At poor countries u can see what u want

 

[Geovr]

Does the flow at the rear of the tractor get less when the Hi-Lo is shifted?? You will have better oil flow when the Hi-Lo is in the position it defaults to with the engine off.
If you put a 0-20 bar gauge in the low pressure test port above the high pressure pump, see if it has pressure when the oil is flowing at max. If the pressure drops to zero, the problem is in the transmission..

May i do this test if there is n"t Hi-Lo on my tractor???

 

[Tractortech]

Yes. It will indicate transmission pump capacity and/or internal leakage..

 

[Cowabunga]

Yes. It will indicate transmission pump capacity and/or internal leakage..

Yes. Internal leakage will often be accompanied by very hot gearbox oil temperature, because the pumps may be constantly pumping. I once had a simple internal seal leak in my 2140 which caused high temperature. Luckily it was at nearly 6000 hours and the HiLo was obviously in need of an overhaul, so was the PTO clutch, so all were done at the same time. As was a new trailer pick-up hitch due to the original ARM unit [I think it was. The Irish type with the two pivoting wedges that was popular in the 1980’s] being completely worn out even after several remedial fabrications. The tractor is still owned locally today with around 12,000 hours on the clock.

 

[Geovr]

Yes. It will indicate transmission pump capacity and/or internal leakage..

Please can u tell me if i can connect the pressure gauge as at photo instead of above the high pressure pump??? My cabin has this window....
I took this photo from a video at utube

Regards

 

[Tractortech]

That picture is testing the pressure of the low pressure pump. You need to test at the front of the tractor as in the picture below 0 - 20 bar gauge. This tests the oil available to the high pressure pump. You can have a gauge in the shift cover as in your picture, it should show a steady 10.5 bar. However, that doesn't indicate what is available to the pump at the front..