284 hydraulic pump problem?

[Amez]

Hi all
Today my loader and 3 point arms stopped raising at low RPM. I can still raise them when I increase the RPM. I assume the pump is not producing enough pressure.
Hydraulic reservoir is full , no obvious leaks.
My first guess would be a blown seal somewhere in the hydraulic pump.
I haven't done any troubleshooting yet but has anyone had this problem before or have any tips?

2007 Jinma 284

Mike

 

[greg_g]

First look for excessive bubbling or foam in the lift box, and then check the engine oil to see if the level is higher than expected.

//greg//

 

[Amez]

Greg
There is no foam in the lift box , engine oil is at normal level.
I recently ( 5 operating hour ago) replaced the Hydraulic oil and filter.

Mike

 

[Amez]

Does the hydraulic pump on the right side of the engine operate both the loader and the 3 point arms? If it does , I suspect the pump , because both are affected.
Is there a relief valve for the 3 point system?

 

[Affordable]

Depending on which engine you have,most have 1-pump for everything,I would say your pump is weak,without a gauge it's hard to confirm.If you need any parts we have them


Tommy
Affordable Tractor Sales Co
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[greg_g]

Does the hydraulic pump on the right side of the engine operate both the loader and the 3 point arms? If it does , I suspect the pump , because both are affected.
Is there a relief valve for the 3 point system?

There is a priority valve between the output of the pump and the input to the steering controller. They've been known to become obstructed. You may have too much fluid going to the steering, and not enough to the rest of the system - which in your case is both lift and loader. Disassembly/cleaning of the priority valve is not difficult.

//greg//

 

[greg_g]

Does the hydraulic pump on the right side of the engine operate both the loader and the 3 point arms? If it does , I suspect the pump , because both are affected.
Is there a relief valve for the 3 point system?

There is a priority valve between the output of the pump and the input to the steering controller. They've been known to become obstructed. You may have too much fluid going to the steering, and not enough to the rest of the system - which in your case is both lift and loader. Disassembly/cleaning of the priority valve is not difficult.

//greg//

 

[erj]

Mike,
Please describe your hydraulic flow. For example on my 284, the flow goes from the Pump to the FEL valve and then to the Priority Valve.

Also do you have access to a pressure gauge? It is a good thing to have for many reasons including this one.
RonJ

 

[Amez]

Thanks Ron
When I turn the steering wheel , while lifting the 3 point (at low RPM) , the 3 point stops.
This makes me think that niether the steering or the 3 point is getting enough flow.

 

[Amez]

RonJ
My flow goes from the pump through the loader to a diverter valve which I believe sends required flow to the steering and the reainder to the 3 point.
I'm waiting for a gauge at the local parts store.
Mike

 

[Affordable]

On The Jinma 254/284 tractors with a loader,the outlet of the pump goes in to the loader valve first then out to the priority valve.A obstruction in the priority valve would not effect the loader if yours is plumbed like most 254/284 are.Get a gauge to confirm the pump pressure.

Tommy
Affordable Tractor Sales
" Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[erj]

RonJ
My flow goes from the pump through the loader to a diverter valve which I believe sends required flow to the steering and the reainder to the 3 point.
I'm waiting for a gauge at the local parts store.
Mike

Mike,
Since both the FEL and 3pt are acting up - and one is before and the other is after the diverter valve, it is probably the pump or the FEL valve pressure release adjustment. Since it is working, I would not do anything until you can get a pressure gauge installed to see what you really have.
RonJ

 

[Amez]

There is a priority valve between the output of the pump and the input to the steering controller. They've been known to become obstructed. You may have too much fluid going to the steering, and not enough to the rest of the system - which in your case is both lift and loader. Disassembly/cleaning of the priority valve is not difficult.

//greg//

Greg
I just removed and cleaned the priority valve. There were no obvious deposits in there , but when I reinstalled it the lift systems seem to work. I won't know if it is full force on the 3 point until I put my hoe or a gauge on.
Thanks for the info.
I assume that the priority valve was diverting flow to the reservoir at a lower pressure than it was meant to effectively bypassing the 3 point lift ?
Mike

 

[greg_g]

I assume that the priority valve was diverting flow to the reservoir at a lower pressure than it was meant to effectively bypassing the 3 point lift ?

Well, I'm thinking the other way around. The priority valve was stuck to where the majority flow was diverted to the steering sub-circuit, thereby starving the loader and the lift. Your later mention that turning the steering wheel made the other hydraulics move - pretty much confirms that. Appears the simple act of removal/reinstallation was enough to unstick whatever was stuck.

//greg//