Rear 3pt arms drop quick

ovrszd · Oct 29, 2022

rkadish said:
The tractor is running when it drops. I will lift the implement to move to a different area, matter of feet mind you, while moving the implement will drop down. I have mainly used a landscape rake. I will rake a section, 200ft, lift the rake to move back to the start and the rake will drop in that time. I usually need to keep my hand on the lift lever if I am going further than that.

It also drops when not running, I do not remember how fast that is.

I will try to remember to time both of them and post it later.

Okay. Not familiar with your tractor model.

Does it have position control 3pt? Lift lever can be placed anywhere in it's path of travel and the 3pt lifts to the same height every time? Usually the slide gate has numbers on it?

Or is it 1/4" valving or something similar? Each time the lever is moved it returns to center and the 3pt raises or lowers a small amount? Similar to a rear remote lever?

Lastly, when the 3pt drops does the lever also drop to a lower position?

K5lwq · Oct 29, 2022

Here is a thread with a similar issue that may help.

3-Point Hitch - Farm Pro (Jinma) 2425 hitch will not stay up

Hello again, I have a Farm Pro (Jinma) 2425 that the hitch will not stay up. There is a adjustment knob under the seat that controls the rate of drop ( I think) and if I tighten it all the way the hitch will stay up, but then it will not drop. I just had it serviced and it did not seem to stay...

www.tractorbynet.com

ovrszd · Oct 29, 2022

If a tractor has Position Control 3pt, and the lever stays where you put it, and the 3pt drops while engine is running, it will "hop". Drop a little, jerk back to original position, drop a little, jerk back to original position. That's what Position Control does,. maintains the 3pt at a specific height dependent on where the lever is resting. This hopping indicates leakage in the cylinder.

Not knowing anymore than I do about this tractor, I'm assuming it's Position Control 3pt. I'm assuming the lever stays where it's resting. I'm assuming the 3pt slowly drops while tractor is running. If these assumptions are true, this is a first for me. Never saw this before.

K5lwq · Oct 29, 2022

If it is position control then the lever is not staying put as he has to raise it back up. Because of this I was assuming it was a 3 position valve with center neutral. Every one of these I have seen require adjusting back to height as you use it. It is due to valve internal leakage in most cases but if excessive I would think piston seals.

ovrszd · Oct 29, 2022

K5lwq said:
If it is position control then the lever is not staying put as he has to raise it back up. Because of this I was assuming it was a 3 position valve with center neutral. Every one of these I have seen require adjusting back to height as you use it. It is due to valve internal leakage in most cases but if excessive I would think piston seals.

Yep. Again, too much missing information for me since I know nothing about the tractor model.

If it's a Position Control system and the lever is "moving" downward that's an easy fix.

rkadish · Oct 30, 2022

I will look for this knob.
I timed it yesterday, it takes a little less than three minutes to drop running or not but stationary. it drops a little faster while rolling around the property.

ovrszd · Oct 30, 2022

rkadish said:
I will look for this knob.
I timed it yesterday, it takes a little less than three minutes to drop running or not but stationary. it drops a little faster while rolling around the property.

Can you clarify the type of 3pt? Is it Position Control or 1/4 inch valving?

bgr · Oct 31, 2022

rScotty said:
Well, since it lifts OK but then drops on its own while running that's a little bit different from the 3pt hitch dropping that we usually hear people dealing with.

It sounds like it is either a leaky 3pt piston/cylinder - or a bad 3pt control valve. My vote would be that it is the piston/cylinder. Instead of rings, a 3pt lifting piston usually has one or more O rings. Those can go bad.
Most tractors have a knob adjustment for 3pt rate of fall located just below the front of the seat. If yours does, then it is easy to test to see if your 3pt piston/cylinder is good or leaking.

To test, trigger the 3pt to lift up your implement and and while holding it up turn the 3pt fall rate adjusting knob all the way in - usually clockwise. What you are doing by turning it in is to shut a needle valve which traps the fluid in the 3pt piston/cylinder and will theoretically hold the implement up forever.... or at least for 5 or ten minutes. Turn the engine off. Don't touch the 3pt control lever. The implement should stay up.
If it won't do that then it is time to renew the 3pt lifting piston seal.
I guess it could be the 3pt lifting valve itself...but probably not. Do the piston seal first.

rScotty

Scotty needs to explain that when the rate adjusting knob is all the way in, the 3ph control valve is out of the circuit. If the 3ph drops then, the piston seals are the problem. if not, they are good. Good tip Scotty. Thank you.