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Hello to the forum!! I'm a long time John Deere user - have had a 4210 for 10 years without a single issue. I've used it for more than I should have more than once, and I just recently bought a 2011 4720 - more horsepower and loader reach.

As an ehyrdo - the tractor moves great, very responsive. But, lift on the loader bucket is very slow. All other functions with the bucket seem to be at normal speed, but just lift is very slow. In fact, at idle, the loader won't lift at all. As far as 3pt hitch, seems also to be OK.

However, the more throttle, the more loader lift will function. No matter what, still slow. And the power of lift at 2000 RPM seems plenty strong - just slow.

I've serviced tractor, new filters, oil. Suction screen wasn't very dirty - cleaned and re-installed.

LoadMatch appears to be "On".

I'm hoping for some suggestions - something else I can evaluate? All of my evaluation of "slow" is based on my 4210. It is twice as fast in function. Is my evaluation just wrong?

Thanks in advance!
Tim
 

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:wgtt:


I'd suspect a bad male or female QD since it just seems to be one function that is affected, or possibly the seals in one of the cylinders. Does the engine labor when trying to lift?

You could swap the hoses to switch the lift/lower/ and dump/curl functions and see if the problem stays on the lift side or moves to the curl side to help narrow it down.
 

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I agree with Kenny's assessment. When reading your post I was also thinking about the possibility of a partially restricted poppet in either side of the hydraulic quick disconnect fittings. You might want to remove and reconnect all of the quick disconnects as a first step in the diagnostic process.
 

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:wgtt:


I'd suspect a bad male or female QD since it just seems to be one function that is affected, or possibly the seals in one of the cylinders. Does the engine labor when trying to lift?

You could swap the hoses to switch the lift/lower/ and dump/curl functions and see if the problem stays on the lift side or moves to the curl side to help narrow it down.
I agree with Kenny's assessment. When reading your post I was also thinking about the possibility of a partially restricted poppet in either side of the hydraulic quick disconnect fittings. You might want to remove and reconnect all of the quick disconnects as a first step in the diagnostic process.
Good idea and a cheap, easy place to start looking.
 

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My loader is slow with the engine at idle but at 1500 RPM, it should operate very quickly with more movement of the joystick. I've not seen much engine RPM difference with LoadMatch on or off but maybe I haven't met all of the requirements for it to work.
 

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Discussion Starter #6
Followup

Hi everyone (I'm not sure what happened to my first reply - I can't seem to find it!!) Anyway...

Thanks for the quick response from everyone. Here is what I tried:

First I disconnected every quick connect, and reconnected them several times. They were sticky at first, then began to behave more normally.

Upon further inspection, I did find one of the metal "cross-over" lines was dented, but I confirmed it was only for the dump/curl function.

I moved the raise/lower hoses for the loader to all combinations on the quick connectors. I did not get any difference in behavior. Still slow in performance. At lowest idle, the loader bucket will not lift more than 4 inches from the ground.

I suppose a next step would be to disconnect the lift cylinders from the frame to measure their timing independently? Will that tell me much if they are not under load? I suppose that the one female connector on the hose could be bad? (I can easily depress the tip with my finger now when the hydraulic pressure is relieved)

Other thoughts?

Thanks in advance - again!?
Tim
 

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If you have the 3rd function on you loader check the T handle isn’t cracked open. Every time I have an issue with my loader it’s because I’ve forgotten to close this after I’ve changed an attachment.
 

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Discussion Starter #8
Sparkhead, I'm not sure what you mean by the T-handle? Being cracked open? I do have a set of Quick Connects on the rear of the tractor, but I can find no apparent valve or anything that might be open. Those metal lines go right under valve on right side of tractor.
 

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Not sure if all of the Deere range has it but mine has a “tap” on the top of the 3rd function block at the back of the tractor which I use to relieve pressure in the lines so I can change attachments. Maybe this is only a feature on the e-hydro versions on the 3rd function. The tap has a tee type handle. Is there anything like this in your hydraulic system?
 

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Not sure if all of the Deere range has it but mine has a “tap” on the top of the 3rd function block at the back of the tractor which I use to relieve pressure in the lines so I can change attachments. Maybe this is only a feature on the e-hydro versions on the 3rd function. The tap has a tee type handle. Is there anything like this in your hydraulic system?
That pressure relief is only on the 3rd function solenoid valve, it will have nothing to do with the just the lift circuit operating slow.

3rd Function Releif.GIF
 

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I'm leaning towards one of the lift cylinders having excessive internal bypass. A not-so foolproof way to test is to use the loader hard for a bit and then check the temperature of each cylinder, the one that is considerably hotter will have bad seals.
A more accurate and messy way is to retract the cylinders, then loosen or remove the line on the base end, then try to retract the cylinders (pressurize the rod end) more. If the seals are bad you will get fluid out of the ports. It is not uncommon for the seals in these JD loader cylinders to go bad.
 

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Discussion Starter #12
Checking back in

Hi all,

@Kennyd - Continuing to diagnose this problem. I didn't go your exact route, but I hope I was trying something acceptable. I ran the tractor pretty hard for about 30 minutes, lots of use of the loader. I didn't detect any heat from the cylinders by touch at all. Then I loaded the bucket full with gool 'ol Arkansas clay - and left it about 8 feet off the ground with the bucket dipped over just enough into the "dip" position. I shut the tractor off and left it sitting there for 30 minutes.

To be honest, it may have dropped an inch - but it was pretty solid. I'm thinking the cylinders must be pretty solid? Would you agree?

Next step, a pressure gauge for my own testing. I bet someone has made one from scratch, or knows a good one to purchase?

Thanks!
Tim
 

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Tim,
We sell a pressure gauge on the website, there is also a video there showing how to use one.
 

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Discussion Starter #14
Pressure readings

Hi all, I finally had time to get a pressure gauge built and perform some testing. Here are the results - after warmup period of time:
Idle - 600 psi
1800 rpm - 1,500 psi
2400 rpm - 2,900 psi
wide open - 2,900 psi

So, I'm surprised at the top reading of 2,900 psi - does that imply that the pressure relief is not set properly at 2,500 psi (which is recommended I believe).

The 1800 rpm setting tells me that I need to be looking at the pump, now. Any other suggestions?

Thanks in advance - as always!!
Tim
 

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Tim, I reread the first post and you didn’t indicate (or I missed it) if you have a cab machine? If so then possibly the cables between the joystick and valve need adjustment? Just another thing to consider.
 

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Discussion Starter #17
Sorry I'm so slow

Hi Kennyd, I thought I had responded to this - so sorry I missed out.

This machine does not have a cab - so it is an open console.

I've watched the valve movement on the SVC, and I can't really identify any kind of limited travel when the control lever is activated. I will say the linkage is a bit "loose", but I do feel like we get a full stroke on the valve.

Next step I suppose is to dismantle the fender and expose the SVC. Would you recommend an "in-line" pressure monitor to evaluate the pump on its own - like a reading directly between the pump and the SCV? From the pressure readings that I reported earlier, the pressure behavior just seems a little strange to me.

Thanks in advance!
Tim
 
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