I have an 08 Jimna Tractor 254 LE w/loader. Split the housing on the hydraulic pump-replaced with new hydraulic pump. Blew the seal on new pump. Found quick disconnet was faulty/broken internally. No QD in system now. Think there may be problem in the pressure relief valve in the hydraulic control valve. How do I troubleshoot this? Any help will be appreciated.
Hi Gary, welcome to TBN.
Since you had QD trouble, I presume you have a loader on your 254, right?
So I'm guessing the hydraulic control valve is the fel valve?
Your pressure line from the hydraulic pump probably goes to that fel valve. There is no pressure relief on or inside that pump. The pressure line then goes from your fel valve back to the 3pt valve. The pressure relief valve is in the fel valve and there is also one in your 3 point lift valve. The faulty QD would block the flow and blow the pump (or seals).
I'm pretty sure the psi is rated for somewhere around 2280psi.
So when you install a pressure guage you need to be using either the fel valve or 3pt to check the psi with a relief valve to be in the loop. If you check it directly from the pump, there is none. You risk blowing the pump again. You can then set the pressure relief valve on the fel valve to about 2250psi. There should be instructions in your manuals to tell you how to adjust the relief on the 3pt valve, but I'm not sure about that. Normally, it is set at the factory and needs no adjustment ... (at least mine were good).
One think I did was install a pressure relief valve right off the hydraulic pump just in case I did not have the QD's on correct or if they were faulty or even If I didn't remember to connect them. That prevents the the pump from blowing up. I got one from Surplus center. It has a return to sump for the relieved fluid. You might consider adding one.
Another thing is if you are ever going to remove your loader, you need to hook up the pressure line to the rest of the tractor so the 3pt still works. If you forget to do that, you could blow the pump. That's also why you need the QD's when removing the loader. Most guys have replace their Chinese QD's with aftermarket QD's for that exact reason. You can get them from Ronald (Ranchhand Tractors) or Tommy (Affordable sales) or from Discount Hydraulics or Surplus Center. Some guys have even taken the check ball out of them so there is no interrupted flow.
Those are a couple of suggestions.
Again, I don't know for certain whether you have a loader of not, but if you do, what I said will help. If you are interested, I did a lot of hydraulic work on my wife's 284 Jinma. You can go to these threads and read about them. There are lots of photos that might help.
Rob-
Click here then go to post #130
My New Jinma
Here is a thread about a
New Ranchhand FEL Valve
And a thread about
New Mods to Loretta's Tractor where the 284 was improved even more.