Jinma 284 Loader Relief Valve issue

MikeBen · Jan 10, 2023

Hi all,

I have a Jinma 284 chinese tractor and am having an issue with the relief valve. I was working on the hydraulics and removed the 4 bolts that hold the needle valve in on the bottom side of the loader valve assembly. Everything in Yellow in the photo fell out, and when I put it back in I believe I put the plunger (?circled in red) in upside down. Also I wasnt sure if the spring above it was part of the assembly so that's not back in there either. My problem is I removed the 4 bolts and needle valve assembly once more and the plunger is jammed in there to where I cant get it. My question is how can I get to it? Can the parts in green all be removed from the top through the hole with the flat screw head? Does the valve body need to be disassembled? Any help would be appreciated. Thank you!

piper184 · Jan 11, 2023

Oh boy, a puzzle with no picture on the box.
Is this the joystick control unit where it actually runs two spool valves by a couple of mechanical linkages? My 2006 284 came with that on the ZL20 loader. Unfortunately the manual does not show an exploded view of the valve. I replaced it early on with a retrofit kit from Ranch Hand Supply. The replacement valve has much finer control as well as the float function. It also has a power beyond port for future use.
I never did have the OEM valve apart, but it may still be in a corner of the shed if I look deep enough.
Wish I had more info for you.
You might try contacting Rolland at Ranch Hand. He is pretty knowledgeable about that kind of thing.

MikeBen · Jan 11, 2023

piper184 said:
Oh boy, a puzzle with no picture on the box.
Is this the joystick control unit where it actually runs two spool valves by a couple of mechanical linkages? My 2006 284 came with that on the ZL20 loader. Unfortunately the manual does not show an exploded view of the valve. I replaced it early on with a retrofit kit from Ranch Hand Supply. The replacement valve has much finer control as well as the float function. It also has a power beyond port for future use.
I never did have the OEM valve apart, but it may still be in a corner of the shed if I look deep enough.
Wish I had more info for you.
You might try contacting Rolland at Ranch Hand. He is pretty knowledgeable about that kind of thing.

Yes I believe it is the same loader valve you're describing. The tractor is also a 2006. I'll attach a few pictures. The float and finer control sounds nice, this ones about as smooth as a dog sh!tting hammer handles

. Thank you for your help! I will give Roland a call.

piper184 · Jan 12, 2023

You didn't say what issue you are having with the relief valve, but just in case you didn't know, there is another one in the 3-point lift valve assy.

MikeBen · Jan 12, 2023

piper184 said:
You didn't say what issue you are having with the relief valve, but just in case you didn't know, there is another one in the 3-point lift valve assy.

Thank you Piper. I thought I laid out my issue fairly well in the initial post? When dissembled I put the plunger in upside down and cant get it back out. I included a picture referencing the part. Did none of that show up? I'm fairly new here. Thanks

oldnslo · Jan 12, 2023

Are there any plugs you can remove to gain access to push that piece out? If not you might have to figure out how to get pressure below that piece and then use air pressure to pop it out. Cover the opening with something to contain parts and oil spray.

piper184 · Jan 12, 2023

You described what happened and your picture came through fine.
What you didn't explain was what caused you to take it apart in the first place.
I only asked because there are other things in the system that can cause pressure issues. The relieve valve in the 3 point, the power steering priority valve and internal leaks, just to mention a few.
It would be nice if there were an exploded view of the internal works.
Best of luck.

MikeBen · Jan 13, 2023

oldnslo said:
Are there any plugs you can remove to gain access to push that piece out? If not you might have to figure out how to get pressure below that piece and then use air pressure to pop it out. Cover the opening with something to contain parts and oil spray.

There is a plug directly above that I can remove but its only about 3/4 diameter and I cant see down to the plunger, just a spring that I'm hesitant to remove. I like your idea! I've been considering pulled the needle valve back out and then turning over the tractor very briefly to see if the hydraulic pressure will push the plunger down and out. Thanks for your input!

MikeBen · Jan 13, 2023

piper184 said:
You described what happened and your picture came through fine.
What you didn't explain was what caused you to take it apart in the first place.
I only asked because there are other things in the system that can cause pressure issues. The relieve valve in the 3 point, the power steering priority valve and internal leaks, just to mention a few.
It would be nice if there were an exploded view of the internal works.
Best of luck.

Sorry about that! I didnt mean to sound snarky just wasnt sure if everything posted properly. I actually took it apart naively thinking it was a "power beyond" port or something similar that I could tie a 3rd function into. It was working properly prior to me screwing it up! The tractor didnt come with any parts manuals so I'm learning by a long series of trial and lots of errors! Thank you again for your continued help.

piper184 · Jan 13, 2023

Some of the Jinma dealers have online parts catalogs. Places like Circle G and Affordable. They are very helpful to see how things are put together.

There are some documents that I have collected over the years and posted on my website. Feel free to have a look and download copies for yourself. I take no credit for any of it, just passing along what others have posted publicly.

Harnerfarm Jinma 284

oldnslo · Jan 13, 2023

You could try turning tractor over briefly. Be best if you can prevent it from starting though. Maybe put the black adjustment in to reduce chance of parts launching into the wild blue yonder.

Are there any cross drill passages large enough for the parts to lost or lodged in?

MikeBen · Jan 13, 2023

Hi All,
So I was able to get the plunger out by briefly turning the tractor over as some of you suggested. I have reassembled it correctly this time and everything works like a charm.
Thanks for all the help.
Mike

oldnslo · Jan 14, 2023

Mike
Thanks for letting us know you resolved this issue and it is up and running again.

electrycmonk · Jan 14, 2023

i'm curious with a "blind" suggestion (pun enforced) about the stuck part inside.... have you thought of using the air compressor with the air gun attachment and a rubber plug to seal up around the air gun nozzle so the air will push it out from the opposite side that you accidentally inserted the part from?

Rick in WA · Apr 5, 2023

I have the same problem on my backhoe with the stuck relief. Does this come out the bottom or the top? I assume the bottom. I have tried using my nut driver to pound it out from the top down, but feel like I might be doing more damage to something under it, and it feels very solid. Unless someone has something different to get it out, I will try running it to see if I can pressure it out. (pump is moving fluid, but absolutely nothing moves. valves had sat awhile and seized up, but they all appear fine now after a good PB blaster soak. I assume the relief is the same way)
Thanks, Rick

piper184 · Apr 5, 2023

Which backhoe do you have?

Post a picture of the valve assembly, it might help others figure out what you have and how it is configured.

Rick in WA · Apr 5, 2023

it is a 2003 backhoe with a tag that says YW-6 followed by 160. It is also the same relief valve assembly as MikeBen posted at the start of this thread.
Thanks, Rick

Rick in WA · Apr 9, 2023

so i managed to get the part circled in red out along with the spring and the silver looking 'piston' out, but the next part that looks like a barrel with the o-ring in it, and the silver looking 'piston', are still stuck inside. The valve body had sat a long time and got rusty, so I am sure it is seized in it. I have put a lot of PB blaster down it, but I just need to know if I am trying to drive it out the bottom, or the top? Anyone know?

piper184 · Apr 9, 2023

Since I have never had one apart, this is just a pure guess.

Working right to left, starting with the screw on cap at the upper right. That should unscrew and the spring should come out easy enough.

The next piece to the left has a precision ground silver area that would be a close tolerance fit to a precision ground bore in the body. IF the hole under the cap is larger than the precision bore, that piece should come out toward the cap.

However the next part to the left (with the o-ring) looks to be larger than the part on its right, so it is possible that everything is supposed to go out toward the left of the picture. I am pretty sure the part with the o-ring can not go out towards the cap on the right.

If the hole where the spring goes is only large enough for the spring to clear, then everything else must go to the left.

The silver precision ground piece to the left of the part with the o-ring, most likely fits inside the part with the o-ring and there is a precision ground bore inside that part.

If there is rust inside, it may have welded the precision parts together. I would suggest using some heat to try and get the housing to expand enough to break the rust bond. You may need to get the housing to 3 or 4 hundred degrees for this to happen. If you can't get it that hot, try to get it to at least 250 and let it cool down on its own. It may take several cycles of this to break that rust loose.

Another thing to try is vibration. Tapping on the housing in all directions during the heat cycles will help get the rust penetrate to soak in better.

Wish I had more experience with this, but on the other hand, kinda glad I don't.