Aaargh! 3-pt hitch not lifting any weight.
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284 International
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Maybe figure out a way to use a floorjack or something under the box blade to get it up into a raised position, with the height adjustment set to full on the three point. Close the lock valve, and see if it will hold the weight it won't lift.
That should allow you to isolate cylinder vs. valve for the fluid bypassing where you want it to be.
With the lock closed, you should be able to move the lift control up and reach bypass pressure-but make sure the pressure relief valve is in the circuit as you have things plumbed.
If it's in the circuit and you can't reach bypass pressure, I don't understand any way it could be something other than the relief valve. There is no other avenue for the fluid to return to the reservoir, and the pump functions correctly, since the loader will reach full pressure.
That should allow you to isolate cylinder vs. valve for the fluid bypassing where you want it to be.
With the lock closed, you should be able to move the lift control up and reach bypass pressure-but make sure the pressure relief valve is in the circuit as you have things plumbed.
If it's in the circuit and you can't reach bypass pressure, I don't understand any way it could be something other than the relief valve. There is no other avenue for the fluid to return to the reservoir, and the pump functions correctly, since the loader will reach full pressure.
Now that I'm certain I have pressure and flow at every valve, I hav returned it stock; no loader, no remotes, no diverter plug.
The 3pt lift will hold the blade up, if I raise the blade manually.
Neither of the relief valves seem to relive anything, even if I close the knob down, I never get above 300psi at 1500rpm or 600psi at 2000rpm (and I'm standing on the arms).
Maybe a leak inside the control valve?
I only have the manual for a US version of the tractor, and the diagrams are poor (and different). I'll post in the yanmar forum to see if anyone has a breakdown of the control valve for my 1602 or similar Japanese model.....
The 3pt lift will hold the blade up, if I raise the blade manually.
Neither of the relief valves seem to relive anything, even if I close the knob down, I never get above 300psi at 1500rpm or 600psi at 2000rpm (and I'm standing on the arms).
Maybe a leak inside the control valve?
I only have the manual for a US version of the tractor, and the diagrams are poor (and different). I'll post in the yanmar forum to see if anyone has a breakdown of the control valve for my 1602 or similar Japanese model.....
284 International
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The fluid is going somewhere, though, since the pump will generate full pressure to the loader. If you aren't losing fluid, there must be a bypass somewhere.
Is there a pressure relief valve on the control valve in addition to one on the lift cylinder?
Is there a pressure relief valve on the control valve in addition to one on the lift cylinder?
There are 2 pressure relief valves on the 1 on HP in and 1 at the knob (both on the lift cylinder)
I'm speculating that the flow that usually goes thru the "open center" to the tank when the valve is not moved is partially open when flow is sent to the cylinder, so some flow goes back to the tank. When the flow is high enough, enough flow is able to go to the cylinder and lift the arms.
Maybe my reasoning is incorrect, I'm a physicist, not a hydraulics expert by any means : )
284 International
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I think your idea makes a lot of sense, and would logically account for the symptoms you're having. I can't see any other possibility.
J_J
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Read this post and see if it makes any sense.
http://www.tractorbynet.com/forums/yanmar/216990-adding-grapple-3.html#post2497320
#29
http://www.tractorbynet.com/forums/yanmar/216990-adding-grapple-3.html#post2497320
#29
I have a positional 3pt hitch, when I raise the lever half way the arms raise unti they get half way. I think there is an arm with a spring that turns the valve to neutral, when it reaches position it is set for. I will take a look at this section, but I believe it is functioning correctly (unless there is an internal leak toi neutral when the lever is trying to make it go up...)
If the lever is set to half way, and I'm standing on the arms, no movement, if I get off, the arms move to half way.
J_J
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284 International,
I am not sure the 3pt can lift with the lock valve engaged. I haven't tried it. Do you know for sure with the valve screwed in tight with the 3pt half up, that you can raise the 3pt. I always thought the orifice that the knob screwed down, closed off the input and the output for the 3pt cyl.
I know the 3pt has a relief valve, but I have not seen the pressure relief settings for any 3pt. It could be equal to or lower than the FEL. It has to have it's own relief, as all tractors don't have loaders. There is also a safety relief, and I have never seen the pressure that will set it off.
The 3pt pressure can be checked by installing a gage in the pressure line anywhere from the 3pt valve to the pump. When you fully raise the 3pt, and it starts to bypass or relieve you can read the pressure. The normal pressure could be anywhere from very low pressure to 3pt relief pressure depending on load.
If the FEL takes all the fluid, you might not have any pressure at the 3pt for a short time.
I am not sure the 3pt can lift with the lock valve engaged. I haven't tried it. Do you know for sure with the valve screwed in tight with the 3pt half up, that you can raise the 3pt. I always thought the orifice that the knob screwed down, closed off the input and the output for the 3pt cyl.
I know the 3pt has a relief valve, but I have not seen the pressure relief settings for any 3pt. It could be equal to or lower than the FEL. It has to have it's own relief, as all tractors don't have loaders. There is also a safety relief, and I have never seen the pressure that will set it off.
The 3pt pressure can be checked by installing a gage in the pressure line anywhere from the 3pt valve to the pump. When you fully raise the 3pt, and it starts to bypass or relieve you can read the pressure. The normal pressure could be anywhere from very low pressure to 3pt relief pressure depending on load.
If the FEL takes all the fluid, you might not have any pressure at the 3pt for a short time.