John Deere 4300 With 430 Loader , loader very slow and non responsive

Joeblack101 · Oct 7, 2017

So I've read a few post on here discussing some of the same problems I've been having , however , mine seems to be a little more difficult . Loader stopped working completely several months ago . Had to pull the lever down and to the left hard to get it to move at all . I flushed the system hydraulics and cleaned the suction screen and replaced the filter . Oil level was a little low and not in the site gauge . After flush loader did start to work a little better as up and down works off lever right but it's very slow . Have to rev up to full throttle to get anything out of it . I do hear it going over relief for loader up and down , and bucket tilt down . Here's the kicker , bucket tilt in works perfect and low idle and full and won't go over relief until the pressure dead heads and it goes over relief at end of the stroke which seems normal . It's the only function that works correctly and I can physically see the lines ' jumping ' when that function is activated at the quick disconnects . So I took out relief valve which is adjustable and found the o ring ok but backing plate to o ring blown . So I ordered kit and replaced and still no difference . I replaced both male and female couplers for loader up and down and made no difference . The relief adjustment seemed very easy to adjust so I replaced the whole relief valve . No diffference . . I know the rubber boot in both pumps doesn't look like it's leaking , I have perfect power steering and 3 point hitch operation . But just screwy loader . Up , down and bucket out are slow as crap .will only move at full throttle but veryyyyy slow. Only one that looks normal is Bucket in . I have not got to put a pressure gauge in the system yet , but I'm assuming since the 3 point works ok and bucket in seems fine that the pumps good . I seen most people solved this by relief blockage but that's not my case . Any help is greatly appreciated . Thanks a bunch .

oldnslo · Oct 7, 2017

Joe,
With the engine off can you check the control valve spool travel on both the raise / lower and curl / dump functions. The spool travel from the spring loaded center condition should be very similar for all of the loader movements. I.e. has something in the linkage come loose?

When you state you can hear the pump going over relief during raise lower. Is this all the time you are trying to move the loader?

Tx Jim · Oct 8, 2017

Welcome to TBN
How old is loader? I'm wondering if one or more boom cylinder piston seals are faulty? With boom totally raised up remove boom cylinders rod end hoses then with engine running move control lever to raise position to determine if oil exits open rod end hose ports.

Joeblack101 · Oct 9, 2017

Thanks for the replys . Loader and tractor I believe are from 1999 or 2000. It may just be my eyes , but there's 3 valves in the loader valve that the joystick is operating . The first one closest to the right fender is loader up and down . And the next one is bucket tilt in and out . It looks like the bucket in and out has more travel in it then when I'm using loader up and down . Linkage looks ok but I put a pry bar in a gently pushed the valve to try to get it to move a little further for loader up and down and it don't move any further then what the lever is taking it . The Bucket in does not go over relief until it fully tilts in , then goes over relief . This is the only function I can use that I don't hear it going over relief . It's constinatly " hissing " with loader up and down and bucket out . Like it's going over relief at all types of throttle except for low throttle . I get nothing other then bucket in at low throttle. It has to be full throttle to get anything else to move . And I hear the hiss of the relief and can feel the tube getting hot that it's relieving the pressure back through . Hope this makes sense

oldnslo · Oct 9, 2017

Joe,
From what you are describing it does sound like there is a restriction some where in your system. The hard part is determining where this restriction is. Since everything is hard plumbed from the valve to the quick disconnects you can only watch the hoses going to the loader. When trying to raise do you see the hoses stiffen or swell like they are under pressure?

Have you tried swapping the hoses from lift / lower to the curl / dump function? I am not sure if you have the regenerative dump feature on this model but it should still raise while operating the curl feature.

Not sure you kept the old quick disconnects but could you make up a jumper hose to remove the lift lower cylinders from the circuit? I.e. just connect a hose across these ports. This would isolate the Loader from the valve and point us in direction of the potential fault area.

If you could get a pressure installed in the pressure line would also be helpful. Not sure if JD put a test point in this circuit or not.

Joeblack101 · Oct 9, 2017

oldnslo said:
Joe,
From what you are describing it does sound like there is a restriction some where in your system. The hard part is determining where this restriction is. Since everything is hard plumbed from the valve to the quick disconnects you can only watch the hoses going to the loader. When trying to raise do you see the hoses stiffen or swell like they are under pressure?

Have you tried swapping the hoses from lift / lower to the curl / dump function? I am not sure if you have the regenerative dump feature on this model but it should still raise while operating the curl feature.

Not sure you kept the old quick disconnects but could you make up a jumper hose to remove the lift lower cylinders from the circuit? I.e. just connect a hose across these ports. This would isolate the Loader from the valve and point us in direction of the potential fault area.

If you could get a pressure installed in the pressure line would also be helpful. Not sure if JD put a test point in this circuit or not.

Yes I can see the line physically jump when the loader bucket in is actuated . It's so much pressure that I can't even turn the hose in the disconnect. After swapping the quick connects I can now ' feel'' some pressure in the loader up and down hoses , but nothing like the bucket in pressure hose has . I can still turn the hoses in the disconnects when it's actuated . Nothing like bucket in . I made a quick connect fitting to test the pressures in each here this evening . I think that will tell if it's a pressure problem from the pump or in the loader valve assembly . But I did try swapping loader up and down with the tilt in and out ... however I think I had the return hose routed wrong in the disconnects bc it instantly jumped the loader up but stopped fast and bogged the tractor . I realized I had it connected wrong so I put it back to normal and went from there . I will test pressures this evening and come back from there .

dfkrug · Oct 9, 2017

Tx Jim said:
Welcome to TBN
I'm wondering if one or more boom cylinder piston seals are faulty?

That is what I suspect, too.

I have been able to hear the oil flowing past a bad piston seal when trying to raise
the FEL. Also, a heat gun will show a significant temp diff between each side. If
one seal is slightly more worn than the other, it will bypass first, and the oil flow
then degrades the seal quickly.

oldnslo · Oct 9, 2017

dfkrug said:
That is what I suspect, too.

I have been able to hear the oil flowing past a bad piston seal when trying to raise
the FEL. Also, a heat gun will show a significant temp diff between each side. If
one seal is slightly more worn than the other, it will bypass first, and the oil flow
then degrades the seal quickly.

Bad seals should not have any adverse effect on lowering the loader only on achieving down force like trying to raise the front end off the ground. Agree bad seals would slow down the raise function.

oldnslo · Oct 9, 2017

Joeblack101 said:
Yes I can see the line physically jump when the loader bucket in is actuated . It's so much pressure that I can't even turn the hose in the disconnect. After swapping the quick connects I can now ' feel'' some pressure in the loader up and down hoses , but nothing like the bucket in pressure hose has . I can still turn the hoses in the disconnects when it's actuated . Nothing like bucket in . I made a quick connect fitting to test the pressures in each here this evening . I think that will tell if it's a pressure problem from the pump or in the loader valve assembly . But I did try swapping loader up and down with the tilt in and out ... however I think I had the return hose routed wrong in the disconnects bc it instantly jumped the loader up but stopped fast and bogged the tractor . I realized I had it connected wrong so I put it back to normal and went from there . I will test pressures this evening and come back from there .

Since you get full pressure in one direction on your curl I doubt that this is a pump problem.

Spanner · Oct 9, 2017

Joeblack101 said:
So I've read a few post on here discussing some of the same problems I've been having , however , mine seems to be a little more difficult . Loader stopped working completely several months ago . Had to pull the lever down and to the left hard to get it to move at all . I flushed the system hydraulics and cleaned the suction screen and replaced the filter . Oil level was a little low and not in the site gauge . After flush loader did start to work a little better as up and down works off lever right but it's very slow . Have to rev up to full throttle to get anything out of it . I do hear it going over relief for loader up and down , and bucket tilt down . Here's the kicker , bucket tilt in works perfect and low idle and full and won't go over relief until the pressure dead heads and it goes over relief at end of the stroke which seems normal . It's the only function that works correctly and I can physically see the lines ' jumping ' when that function is activated at the quick disconnects . So I took out relief valve which is adjustable and found the o ring ok but backing plate to o ring blown . So I ordered kit and replaced and still no difference . I replaced both male and female couplers for loader up and down and made no difference . The relief adjustment seemed very easy to adjust so I replaced the whole relief valve . No diffference . . I know the rubber boot in both pumps doesn't look like it's leaking , I have perfect power steering and 3 point hitch operation . But just screwy loader . Up , down and bucket out are slow as crap .will only move at full throttle but veryyyyy slow. Only one that looks normal is Bucket in . I have not got to put a pressure gauge in the system yet , but I'm assuming since the 3 point works ok and bucket in seems fine that the pumps good . I seen most people solved this by relief blockage but that's not my case . Any help is greatly appreciated . Thanks a bunch .

What do you mean by you "flushed the system hydraulics"?

What was the condition of the suction screen? What sort of debris, if any, were found??

A lot of disconnecting and replacing has been going on here so it's pretty hard to pinpoint your problem.

The "backing plate to O-ring was blown" so did you retrieve all the pieces?

Loader finally "stopped working completely several months ago". How long had you noticed it getting slower?

And I read that you clearly never check your fluid level in the trans. It's not surprising that you have an issue now.

Check for obstructions in the Quick Connetors. Oil has to travel through smaller passages here. Swap the couplings for Raise/lower and Curl/uncurl to see if the problem is hose-related or valve-related.

Joeblack101 · Oct 10, 2017

So I wanted to come back with my findings . In the book the quick disconnects are labeled A B C D from left to right if sitting on the tractor . I knew B was working for bucket in so I started there . Plugged in the test gauge and I had 1800 psi , I adjusted relief valve and got pressure to spec at 2500 psi . So I know the pumps ok . I went to port A for bucket out , I had 1500 psi ( I'm guessing it don't need as much for bucket down and loader down . Went to port C , Loader up ( 1000 psi ) ... and A loader down (1500 psi )

A: bucket out : 1500 psi
B: bucket in : 2500 psi
C: loader up : 1000 psi
D: loader down : 1500 psi ..

So I looked real close at the linkage on the valve and it's almost like it's stuck from moving any further . Like something is binding in that valve block assembly . I looked real close with a bright light, and you can see it is half shiny further back the valve like it used to travel that far . So I can't get a parts breakdown for the valve assembly any more . Only a whole knew valve which is 997$

... so I guess my next step will be tear the valve or spool out and see what's going on

oldnslo · Oct 10, 2017

On the end opposite the linkage there should be a cover over the end of the valve spools. Carefully remove this cover. There should be a spring or springs held in place via some method. Could be retaining ring or bolts. Confirm nothing is out of position or binding in this area.

On the lift lower spool there will also be the detent feature for float. I am not sure how this is assembled on your valve so be very careful since there could be some spring loaded pieces under this cover.

Pressure should be similar for all functions.

Dutch445 · Oct 11, 2017

I wouldn't rule out having some of the hoses in the wrong place,
if you have crossed circuits thru all of this nothing will act right and be very hard
to diagnose.
switching circuits to test them was a good idea, but, are you 100% sure that you have
the right circuits matched together going to the same valve?
(might take a little detective work, following hoses up to the loader, and then make
sure you have the same circuit at the quick disconnects from the valve)
i know a lot of the color coded dust caps have been lost by not on tractors this age,

Joeblack101 · Oct 13, 2017

Sorry if there was confusion in my posts . Loader was used to clear some ground for a patio and then started acting up . Yes it was a low on fluid and I only put 40 hours on this since purchasing it . Because I never serviced it and had no clue when someone did , I drained fluid , cleaned the suction screen . There wasn't much in the screen . At least I expected it to be more honestly . The backing plate was very brittle but I could not find any of the other pieces in the manifold . So idk where they went . But I kinda ruled out the quick disconnects by replacing male and females . And the pressures just aren't right . No I wanted to triple check myself with the connections bc I know how easily they can be screwed up after swapping . These had the color caps still clearly visible so I have the colors matched from where they were when it probably worked correctly . Weather has been crappy here past few days . I'd like to tear the back cover of the valve assembly off this weekend to see what I can find with it . I can see it barely moves the spool in the loader up and down valve . And feels like it's jamming . So I will post what I find to possibly help someone else if they have this problem . Thankyou again for all the help on here . I very much appreciate it

oldnslo · Oct 13, 2017

Joe,
If the spool barely moves I would definitely suspect that something in / under the end covers is the problem. People have found them full of water, rust, mud, etc. I certainly hope it is as simple as good cleaning with no expensive unobtanium parts required.

Joeblack101 · Oct 28, 2017

So I know it's been a few weeks but I finally figured it out . I'm attaching images . I removed the PTO linkage that connectors to tractor ( what a pain , ) then got the cover off the rear. I suspected to find a broken spring or something , but nope . All had plenty of lube and looked ok. I removed the spring on the valve giving me issues and I could get the D tent ' cup ' to engage and disengage by hand . And functioning ok . But the valve was so stuck it wouldnt come out more then 1 inch. I broke some rules and got out a punch and hammer . I had to use the hammer to force it out . It was in there to the point I had to hit pretty hard . Finally broke it free . A bunch of Oily crap fell out the back and I couldn't tell exactly what it was bc it fell on the dirty transmission . I seen virtually no scaring on the spool valve once removed . So I checked inner and outer O rings and found no issues . So I just cleaned the valve and everything else the best I could . It went in easier , still a little tight . But I reassembled and thought , screw it . I'll try ... and low and behold it works like new !!! Still a little bit tighter then I would like but it's working flawlessly and goes into d tent just fine now . All loader functions are perfect . Something was blocking it from full movement . I'm just happy the 900$ valve assembly didn't need to get ordered . So now I'm back in business . Thanks for the help and replys on this . I know in the future I might need to replace the whole assembly since I can't get individual parts anymore , but for now it works great