JD4300 3PH won't go down?

[manwith2jd]

Another newbie in trouble!
JD Bushhog was attached, moved tractor w/bushhog, went to lower to disconnect and wouldn't lower. Looked around nothing obvious, then opened the rate of drop knob a bit and it lowered. Disconnected the mower and raised and lowered the 3PT lift a couple times. Now it's back to not lowering and have tried backing out the rate of drop knob, etc. no help! Fluid level is ok! Any input on proper and order of steps to troubleshoot would be so much appreciated. Hydraulics not my forte so please go slow! Other info, Tractor has a 430 FEL and it seems to function fine. 3PH will raise and will put load on motor when topped out,that seems normal. Checked linkage, seems to be all in place. If anything is different, the rockshaft lever seems to move easier in the lower direction, but might just be my imagination!
Thanks

 

[rdbrumfield]

I have been having the same problem with my 5300. sometimes I have to shake the tractor by dumping the clutch a bit to get it to release. Has to be the return valve in the release system. I hate to tear into that one. It doesn't do it all the time, so I guess until it really becomes a problem I will deal with it. I hang about a ton on it and it still hangs now and then.

 

[kennyd]

I think problem is with the lock valve also...I seem to recall in the cobwebs of my brain that there was a few problems with them for a while. I also remember they added a in-line filter to the rear of the tractor for some problem-but not sure if its the same issue.

You could asked a dealer to search for any DTAC cases on this, and he can also run your serial number to search for any updates.

I think you will need to remove the valve and see if anything is in there that is not supposed to be. The service manual will be invaluable for this if you can wait...You can (or I can do it for you) look at the parts breakdown on JDParts.com if you need to start tearing apart before you get the manual.

 

[manwith2jd]

Thanks guys for the info, will go to dealer today and check on things suggested. I had already printed out parts info from site. Don't recall seeing what you described as "lock valve" but will look again. Also, tried the dumping clutch thing, but with no implement attached, and didn't work. Thanks again.

 

[kennyd]

Don't recall seeing what you described as "lock valve" but will look again.

I meant the rate of drop valve-what's connected to the knob under the seat. I should not have used the term "lock valve", sorry to confuse things

 

[manwith2jd]

Problem solved! Yes it was the "rate of drop valve"! Thanks for you guy's help! I did talk with dealer and he said this issue more prone to less frequently used machines, which mine falls into that category.
Also, Kenny you were correct on retrofit filter kit, but only used with backhoe,fyi.
Thanks again, I'm sure I'll have other issues down the road, and will need more advice!

 

[kennyd]

Problem solved! Yes it was the "rate of drop valve"! Thanks for you guy's help! I did talk with dealer and he said this issue more prone to less frequently used machines, which mine falls into that category.
Also, Kenny you were correct on retrofit filter kit, but only used with backhoe,fyi.
Thanks again, I'm sure I'll have other issues down the road, and will need more advice!

Great news!

What exactly was the "fix"?


I have a friend with a 4400 and NO backhoe...and they put the newer inline filter on his?

 

[manwith2jd]

Great news!

What exactly was the "fix"?


I have a friend with a 4400 and NO backhoe...and they put the newer inline filter on his?

The service manager at my local Deere dealer told me the that manufacturer only recommended installation of the inline filter when tractor had BH installation.
(Using "Rockshaft Cylinder Head and Piston Diagram from JD Parts Cat.)
As far as my issue, I just removed the 2 bolt flanged support (item #5)and removed the adjustment rod assy. This exposed the "rate of drop valve" (#9) at least the end of it. Afraid of damaging the valve by pulling out by mechanical means. So, I just lifted up some on the lift arms, and forced it out, shot out in fact! Cleaned everything up real good, re-installed valve and flange support. Assume, the valve was just stuck in the closed position. FYI, this "rate of drop valve" does have a tapped hole in the end that is exposed when you remove the flanged support. I didn't take the time to figure out what the thread tap size was, but looked to be 10/24, 10/32, or similiar metric thread around that size. If I ever have to address this in the future I would probably install a screw in this valve spool to remove next time, versus firing it out of the valve body using the oil pressure from lifting the lift arms.
I hope this is what you were asking?
Thanks again, I'm just a little timid on working with hydraulics, but learning!

 

[kennyd]

I hope this is what you were asking?

That is exactly what I wanted to know...Thanks for taking the time to write it up-I am sure it will help someone in the future

 

[jtaucrkn]

Could this under the seat valve have anything to do with the 3 pt arms not lifting? Just quit for no apparent reason.