Jinma / JW03 Backhoe Hydraulic pressure release valve

[IBPALLETS]

When you take this apart for checking you drop the bottom bowl which is the adjustment- then on top is a screw out threaded cover which you remove . Do the in between parts come out pushing from the top or bottom ? They dont seem to want to come out and dont want to force something. ?

 

[Jimbr549]

I have the exact same question, hopefully someone with experience will chime in.

 

[Bob Rooks]

When you take this apart for checking you drop the bottom bowl which is the adjustment- then on top is a screw out threaded cover which you remove . Do the in between parts come out pushing from the top or bottom ? They dont seem to want to come out and dont want to force something. ?

Do you have symptoms that might require disassembly? If so, what? They aren't part of routine service.

 

[Jimbr549]

In my case I have a non-functioning backhoe. Oil is flowing fine from the pump and through the reservoir, but absolutely zero response from the controls.

 

[Bob Rooks]

In my case I have a non-functioning backhoe. Oil is flowing fine from the pump and through the reservoir, but absolutely zero response from the controls.

What were you doing when this symptom started?

 

[Jimbr549]

What were you doing when this symptom started?

I bought the backhoe in this condition. Cheap. I'm talking "Just get it outta my yard!" cheap.

The backhoe is not currently connected to the tractor, and I'm not likely to begin working on it until all the other spring tractor chores are done, so I'm just exploring ideas for a fix.

 

[Bob Rooks]

There is an acorn nut on your valve stack, remove it, then loosen the lock nut. With a screwdriver, remove the adjusting screw being careful to count the number of turns (write it down). Remove the spring and plunger (or ball) and inspect for debris. Reassemble in reverse order being careful to count the number of turns against the spring as this controls your operating pressure of around 2,500 psig.

 

[PAULWILKIE]

When you take this apart for checking you drop the bottom bowl which is the adjustment- then on top is a screw out threaded cover which you remove . Do the in between parts come out pushing from the top or bottom ? They dont seem to want to come out and dont want to force something. ?

When I had that backhoe I had the same issue. Nothing worked. What the issue was a O ring had sucked through the line. It stuck in the pressure release value. So it was bypassing and it would not allow flow to any cylinders. That would be my first thing to check.

 

[IBPALLETS]

Well we got it apart with tractor mech help - now we have another problem one part fell into the hole from hell where ever that is . looked three days and cant find - anybody have a junked control box they want to parts out - And BTW there was chewed up O ring which has been my problem before . now I have a new one.
ANY BODY WITH A SCRAPED CONTROL BOX THEY WANT TO MOVE I DOUBT THATS A ORDER PART ???

 

[Bob Rooks]

Well we got it apart with tractor mech help - now we have another problem one part fell into the hole from hell where ever that is . looked three days and cant find - anybody have a junked control box they want to parts out - And BTW there was chewed up O ring which has been my problem before . now I have a new one.
ANY BODY WITH A SCRAPED CONTROL BOX THEY WANT TO MOVE I DOUBT THATS A ORDER PART ???

The term "control box" might confuse some. There are lots of backhoe valve stacks available. Quality will vary. I think a Prince valve stack will run North of $600. Here is a budget model.

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