Leejohn
Elite Member
Any luck yet?
Aaargh! 3-pt hitch not lifting any weight.
- Thread starter project_X
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just a note, I had the exact same problem this weekend, my hitch just stopped working all of a sudden. My problem was 2 of the o-rings got sucked into the lift control valve. Took me a while to find the o-rings they were well hidden. Your problem may not be o-rings but any sort of debris getting caught in that valve is enough to stop the hitch.
So i was finally able to get at it. I pulled the control valve and took it all apart and cleaned it out. There was nothing of note stuck anywhere. I then replaced all the O-rings, checked the springs and re-assembled.
Once back in the tractor, I tested the lift..... : ( (it worked exactly the same).
Once back in the tractor, I tested the lift..... : ( (it worked exactly the same).
J_J
Super Star Member
- Joined
- Sep 6, 2003
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- 18,952
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- JACKSONVILLE, FL
- Tractor
- Power-Trac 1445, KUBOTA B-9200HST
project_X,
If I remember tight, you are saying you have 3000 psi at the 3pt and it will not lift.
Where did you have the lever when you measured the pressure?
Was the relief going when you read the pressure?
What is the pressure with the lever half way down?
Where do you think the fluid is going if it is not going into the 3pt cyl?
Your descent knob is screwed out and not closed off?
If I remember tight, you are saying you have 3000 psi at the 3pt and it will not lift.
Where did you have the lever when you measured the pressure?
Was the relief going when you read the pressure?
What is the pressure with the lever half way down?
Where do you think the fluid is going if it is not going into the 3pt cyl?
Your descent knob is screwed out and not closed off?
To recap:
I was seeing 2200 psi from the pump when I tripped the relief valve (when dead heading in to a quick connect).
When the flow is low (1500rpm), the gauge reads 250psi and the arms won't lift if there is a load on them.
When the flow is higher (2200rpm), the gauge reads 500psi and the arms lift a 200lb load.
The descent know is open (which is evident in the instantaneous drop of the lift arms if you move the lever down). I have tested many positions of the knob, and looked at the mechanism which does move and changes the rate of descent of the arms (when the lever is pushed down).
Currently I am just working with the 3pt hitch now (i disconnect the remotes, the loader and hp bypass for the remotes) but it behaved the same when everything was inline or with it removed.
I can lift weight with the loader and the rear remotes (enough to for each of them to lift the front and rear of the tractor).
Where is the fluid going? I have no idea, i though it was the control valve leaking internally,...
-the lift valve will hold any weight I put on it indefinitely (If I jack the weight up)
-the relief valve is on the remote circuit when the remotes are plumbed and 2200 psi is reached if the quick connects are closed
-It could be the safety valve, but the spring seems strong and the ball and seat are good. I also added extra shims and they didn't make a difference.
Currently I'm at a complete loss....
J_J
Super Star Member
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- JACKSONVILLE, FL
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- Power-Trac 1445, KUBOTA B-9200HST
You should be able to test the safety valve by lifting the 3pt up. Lock the descent knob down, and place a heavy load on the 3pt. If your 3pt lift limit is 1000 lbs, it will either hold up to the limits of the valve or push the fluid out of the cyl.
J_J
Super Star Member
- Joined
- Sep 6, 2003
- Messages
- 18,952
- Location
- JACKSONVILLE, FL
- Tractor
- Power-Trac 1445, KUBOTA B-9200HST
The safety relief is probable set at a higher pressure than the 3pt relief valve, so whatever weight you put on the 3pt, it will take more weight to build up pressure and pop the safety valve, and it will only relief to the set safety relief pressure, and then stop. This will test your cyl seals and any valves associated with the 3pt.
There might be a port you can put a hyd gage and see the safety relief pressure when it starts to relieve.
There might be a port you can put a hyd gage and see the safety relief pressure when it starts to relieve.
Leejohn
Elite Member
Man I can't believe you didn't fix it. There is only one other thing I can think of.
On my JD I put a hyd front trailer hitch on and I had to add or remove a plug up inside the rockshaft can't remember of sure. Yours might not even be like mine was, but there was 2 hex head plugs on the back side of the rockshaft and the plug was under one of them. You can see threads down inside under one of the plugs. I'm thinking if it has the plug, it might of came loose. Only one of the outside plugs has threads down inside. The plug down inside is a allen socket plug. If it came out I don't think it can do anything other then block a hole.
I had a service manual, but gave it to a guy on here so I can't go look at it.
On my JD I put a hyd front trailer hitch on and I had to add or remove a plug up inside the rockshaft can't remember of sure. Yours might not even be like mine was, but there was 2 hex head plugs on the back side of the rockshaft and the plug was under one of them. You can see threads down inside under one of the plugs. I'm thinking if it has the plug, it might of came loose. Only one of the outside plugs has threads down inside. The plug down inside is a allen socket plug. If it came out I don't think it can do anything other then block a hole.
I had a service manual, but gave it to a guy on here so I can't go look at it.