# JD310E Weaker / slow Hydraulics



## Allischalmerhd5 (11 mo ago)

Recently my 310E does not want to lift a full bucket load of freshly dump dirt .I need to back up out of pile for bucket to lift. I have checked fluid level and psi at loader port, which was around 2800psi. Not sure what to check next! TIA

Edit to fix psi reading to correct amount


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## Tx Jim (Jul 28, 2020)

Welcome to the TF
According to Tractordata loader hyd pressure should be 2750 psi.


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## Allischalmerhd5 (11 mo ago)

Tx Jim said:


> Welcome to the TF
> According to Tractordata loader hyd pressure should be 2750 psi.


Messed that one up, i corrected the original post to reflect the psi reading i took


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## Tx Jim (Jul 28, 2020)

How long since you installed new hyd filters?


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## FredM (Nov 18, 2015)

Have you raised the bucket to around shoulder height empty and watched how quick the bucket sinks back to ground level?, if this happens then you need to replace the piston seals on the lift rams, if you have hydraulic pressure as you say, then the piston seals are allowing the oil to bypass.

If the above is not the case, then you will need to check if the lift spool is travelling its full travel in the controller.


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## Tx Jim (Jul 28, 2020)

FredM
May I ask a question.?
If boom cylinder piston seals are faulty allowing oil to pass by piston & piston was to travel deeper into cylinder barrel where does the excess oil end up that the cylinder rod will displace the area inside of cylinder providing control valve spool isn't leaking internally?
Thanks, Jim


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## pogobill (Jan 31, 2012)

Jim, I think Fred is saying that if the boom is lifted and the bucket is flat, the weeping bucket would pull the rams out of the cylinder.
Still need to make up the fluid volume somehow, whether needing more as the ram comes out, or needing less as the ram contracts, as you said.
Now you got me thinking my joystick is bypassing a tad, cause my bucket will curl down over time.


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## Tx Jim (Jul 28, 2020)

FredM stated bucket sinking from shoulder height to ground level which lead me think he was referring to boom not bucket cylinders! 

FEL bucket curling forward dumping material is possible due to faulty bucket cylinder piston seals because rod will come out of cylinder not need to go in cylinder when boom is lowering


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## Allischalmerhd5 (11 mo ago)

I replaced the hyd filter last year , cut it open no metal that i could see other than what the tool made. the front bucket would sink after a few days, i am not sure on the fluid quality / condition its been in there awhile. That a big hit for me to change being the machine just sits on farm does not get used much. This condition has been going on for about a year now. i am not convinced the pump is bad, because i have decent psi, I do not own a flow meter. kinda at a loss


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## FredM (Nov 18, 2015)

Tx Jim said:


> FredM
> May I ask a question.?
> If boom cylinder piston seals are faulty allowing oil to pass by piston & piston was to travel deeper into cylinder barrel where does the excess oil end up that the cylinder rod will displace the area inside of cylinder providing control valve spool isn't leaking internally?
> Thanks, Jim


Thanks for the question Jim!!, I would expect that you have seen a spool valve removed from its galley in the controller, usually there will be 3 lands on a smaller controller (lands--the section of the spool that carries and seals the spool in the galley) between the lands there are machined openings so when the lever is moved to the raise position, high pressure oil will flow through the machined opening to the lift side of the cylinder piston, the other machined opening on the spool will open the return oil port which allows the non pressure oil in the cylinder to flow back into the reservoir, the control valve will have at least 4 ports, 2 pressure ports and 2 return ports, so in effect, if the piston seals are leaking, the pressurized oil that goes to the lift side of the ram piston will bypass the seals and flow into the non pressure side of piston and return to reservoir through the hose, pipes and controller ports, and hence very slow lift if the seals are bad enough.
OOPS!! I didn't answer your question correctly, when the boom is raised and holding, if there is leakage in the piston seals, then the oil under pressure from the boom weight will leak past the seals and go into the opposite side of the ram piston and that side of the cylinder will act like a reservoir for the displaced oil.

I refer to the lift cylinder as the main ram to lift the boom, you blokes call it a boom cylinder, we have different wordings and at times can be hard to decipher both ways across the pond.

P is pressure, T is tank or reservoir, A can be the lift side of cylinder, B can be down force of cylinder, a easy way to show the oil flow.


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## FredM (Nov 18, 2015)

FredM said:


> Have you raised the bucket to around shoulder height empty and watched how quick the bucket sinks back to ground level?, if this happens then you need to replace the piston seals on the lift rams, if you have hydraulic pressure as you say, then the piston seals are allowing the oil to bypass.
> 
> If the above is not the case, then you will need to check if the lift spool is travelling its full travel in the controller.


My bad!!, bucket should read boom, sorry blokes.


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## Tx Jim (Jul 28, 2020)

FredM said:


> Thanks for the question Jim!!,
> OOPS!! I didn't answer your question correctly, when the boom is raised and holding, if there is leakage in the piston seals, then the oil under pressure from the boom weight will leak past the seals and go into the opposite side of the ram piston and that side of the cylinder will act like a reservoir for the displaced oil.
> 
> I refer to the lift cylinder as the main ram to lift the boom, you blokes call it a boom cylinder, we have different wordings and at times can be hard to decipher both ways across the pond.
> ...


So are you stating in your opinion that if main ram(boom) cylinder piston seal gets faulty that this fault will allow main ram(boom) cylinder piston to enter further in the cylinder barrel allowing boom(main frame) to lower?? The reservoir area in rod end of cylinder you mention decreases immensely from area that the cylinder rod occupies as cylinder draws together.


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## FredM (Nov 18, 2015)

Getting technical, but that is what I am saying, bearing in mind when the bucket is on the ground, the piston still has a fair bit of travel before it reaches the end of the cylinder, so doesn't fully displace the oil.

Haven't you seen a boom slowly sink back to the ground??, where do you think the oil goes??.


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## Tx Jim (Jul 28, 2020)

IMHO providing technical information is the only real solution.
Fel I've seen when boom is resting on the ground both cylinders are about 95% + retracted. Therefore from fully extended to nearly retracted ""cylinder rod will occupy at lot area inside cylinder"" that will limit space for oil leaked by faulty piston seal. 

IMHO if FEL boom lowers very much then control valve must be the culprit leaking oil between spool & control valve housing.


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## Allischalmerhd5 (11 mo ago)

FredM

Any thoughts or suggestions on my issue?


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## Tx Jim (Jul 28, 2020)

Where exactly at loader port did you check pressure? It's possible pressure relief valve(item 8 1st link) in loader valve isn't holding correct pressure. Also filter(item 11 2nd link) could be plugged.


https://partscatalog.deere.com/jdrc/sidebyside/equipment/81215/referrer/navigation/pgId/619016237




https://partscatalog.deere.com/jdrc/sidebyside/equipment/81215/referrer/navigation/pgId/619024315


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## Allischalmerhd5 (11 mo ago)

Tx Jim said:


> Where exactly at loader port did you check pressure? It's possible pressure relief valve(item 8 1st link) in loader valve isn't holding correct pressure. Also filter(item 11 2nd link) could be plugged.
> 
> 
> https://partscatalog.deere.com/jdrc/sidebyside/equipment/81215/referrer/navigation/pgId/619016237
> ...


I took my reading at this port.


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## FredM (Nov 18, 2015)

Tx Jim said:


> IMHO providing technical information is the only real solution.
> Fel I've seen when boom is resting on the ground both cylinders are about 95% + retracted. Therefore from fully extended to nearly retracted ""cylinder rod will occupy at lot area inside cylinder"" that will limit space for oil leaked by faulty piston seal.
> 
> IMHO if FEL boom lowers very much then control valve must be the culprit leaking oil between spool & control valve housing.


Ok!! YHTC, watch it don't FO.


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## Tx Jim (Jul 28, 2020)

Have you been regularly greasing boom/bucket hinge locations.


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## Tx Jim (Jul 28, 2020)

FredM said:


> Ok!! YHTC, watch it don't FO.


Sorry I don't understand what the letters YHTC & FO indicate. I guess I've got denser in my old age!!


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## FredM (Nov 18, 2015)

Tx Jim said:


> Sorry I don't understand what the letters YHTC & FO indicate. I guess I've got denser in my old age!!


Quite simple!! ---- You Have the Chair, watch it don't Fall Over!!.

Can you answer this? -- will rubber piston seals outwear the steel used in spool valves and the controller body?? seeing that science is being used instead of Murphy's law!!.


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## Tx Jim (Jul 28, 2020)

FredM said:


> Quite simple!! ---- You Have the Chair, watch it don't Fall Over!!.
> 
> Can you answer this? -- will rubber piston seals outwear the steel used in spool valves and the controller body?? seeing that science is being used instead of Murphy's law!!.


No I can't answer your question due to too many variables. 

If my chair falls over I'll attempt to set it back up!


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