1966 John Deere 2510 jittery Hydraulics

[lsaami]

Howdy folks, and happy thanksgiving! I tried reviewing other threads before making this post, but nothing seemed to apply to what i'm experiencing.

I have new to me 2510 diesel synchro-range that has about 3500hrs on it. when i got it, the new idea loader ran off the rear remotes with an open center valve, so I did the right thing and plumbed the hydraulics into the PB with all new closed center valves, hoses and fittings. It was an expensive job.

Now, however, I am getting poor hydraulic performance and jittering when operating the loader and sometimes the 3 point if i move the lever too fast. I only seem to get smooth operation when the tractor is screaming at over 2000RPM. It also seems that I can drive around for a good 30 seconds at 1500rpm, which should allow the transmission pump to catch up, and i still have jittery hydraulics unless i get that RPM up over 2000.

It seems to me that something is up with the tranmission pump. I drained the fluid, replaced filter and cleaned the suction screen when i replaced the valves and hoses. no signs of dirt or contamination in the old fluid/screen.

attached are photos of where i connected to supply/return for the loader. I am 100% positive the valve is closed center.

Thanks in advance for any guidance!

This post was edited by lsaami on 11/23/2023 at 11:20 am.

 

[Tx Jim]

I read where you stated your new FEL control valve is set up for closed center. Does this valve have a built in relief valve? If so I'll advise to close that valve completely as it not needed on Ag tractor with closed center hyd's. Simple test is disconnect hose swivel in your last photo & cap the 90 elbow. Aim open hose swivel in hyd filler hole or clean container. Start engine with foot off clutch pedal & FEL control lever(s) in neutral. No oil should exit open hose with engine operating. I've diagnosed similar hyd problem yrs ago when hyd's not performing correctly & finally located a blown inner seal on a closed-center conversion plug that I thought was good & it was blown.

 

[Bob Bancroft]

You may eventually want to consider replacing the original 4 piston pump with an 8 piston pump. I believe they made an in between
size one for the 2510/2520 tractor. I put a 4010 pump in my 2520. I was surprised that it had a 4 piston pump. Apparently they
used them up in the first 2520's.

 

[lsaami]

(quoted from post at 14:42:36 11/23/23)
I read where you stated your new FEL control valve is set up for closed center. Does this valve have a built in relief valve? If so I'll advise to close that valve completely as it not needed on Ag tractor with closed center hyd's. Simple test is disconnect hose swivel in your last photo & cap the 90 elbow. Aim open hose swivel in hyd filler hole or clean container. Start engine with foot off clutch pedal & FEL control lever(s) in neutral. No oil should exit open hose with engine operating. I've diagnosed similar hyd problem yrs ago when hyd's not performing correctly & finally located a blown inner seal on a closed-center conversion plug that I thought was good & it was blown.

Thanks for this, I ll give it a try. I did make sure to turn the relief in a ways as I could hear the hydraulics cycling initially when I first installed it.

 

[WTW]

You have made the correct connections to tractor, New valve is correct if it is a Closed
Center valve. Now you need a pressure gauge in an SCV outlet to confirm standby / pump pressure
is at / near 2200 - 2250 psi. If it is below 1800 psi you may not get supply / flow to loader
valve because the pressure control / priority valve can shut oil flow off to secondary circuits
to protect steering. Does tractor steering work? If so, problem may be pump pressure needs to be
adjusted up and or hydraulic pump repaired. If pump pressure is in spec. I then would check
transmission pump flow per service manual instruction. You don't have to have a flow meter but
is a good option, A simple flow test using a bucket and stop watch can be used measuring flow
from charge circuit. The four piston pump is going to be slow but should work much better than
what you got.

 

[lsaami]

(quoted from post at 20:45:02 11/23/23) You have made the correct connections to tractor, New valve is correct if it is a Closed
Center valve. Now you need a pressure gauge in an SCV outlet to confirm standby / pump pressure
is at / near 2200 - 2250 psi. If it is below 1800 psi you may not get supply / flow to loader
valve because the pressure control / priority valve can shut oil flow off to secondary circuits
to protect steering. Does tractor steering work? If so, problem may be pump pressure needs to be
adjusted up and or hydraulic pump repaired. If pump pressure is in spec. I then would check
transmission pump flow per service manual instruction. You don't have to have a flow meter but
is a good option, A simple flow test using a bucket and stop watch can be used measuring flow
from charge circuit. The four piston pump is going to be slow but should work much better than
what you got.

Thanks for this. Any recommendations on a gauge? Last gauge I bought was from scamazon and it did not serve me well.

The steering works beautifully with no weight on the loader. I definitely feel a lot more resistance with a full bucket of sand or manure.

I ran the tractor good for a couple hours this afternoon and the jerkiness seemed to stop after about 45 minutes of running it. Not sure if that was the fluid warming up, or if something changed. I can live with slow hydraulics, I understand the little 4 piston pump isn t a champ, but jerkiness means something isn t right.

 

[Tx Jim]

You should be able to get a good hyd gauge at Surplus Center or Bailey Hyd's just to name a couple of hyd supply business's. It's odd for hydraulics to function better after 45 minutes of use because hyd's tend to fail more after the hyd oil gets warmer.

 

[lsaami]

(quoted from post at 05:21:43 11/24/23)
You should be able to get a good hyd gauge at Surplus Center or Bailey Hyd's just to name a couple of hyd supply business's. It's odd for hydraulics to function better after 45 minutes of use because hyd's tend to fail more after the hyd oil gets warmer.

Thanks for this.

I confirmed again with another day of moving logs, hydraulics start to function much better once everything is used for a good while. I also can raise/lower the bucket several times with the clutch depressed, even with the jitters, so it leads me to believe the transmission pump is operating correctly and the under hood reservoir is being filled.


I also tightened the relief valve in the loader joystick. That caused no change.

I have a hydraulic gauge on the way, we ll see what kind of pressure we have. I m starting to suspect the front pump or destroking system.

 

[Harry in Ky]

I'm curious if you've considered making some attempt to measure the oil temperature at various points in time while using the tractor up to and after the condition quits and things seem to work right?

 

[lsaami]

(quoted from post at 10:03:26 11/28/23) I'm curious if you've considered making some attempt to measure the oil temperature at various points in time while using the tractor up to and after the condition quits and things seem to work right?

Not a bad idea. I ll do that next. If nothing else for curiosities sake.

 

[Harry in Ky]

It won't solve anything, granted, but it might help to know if there is any direct correlation between oil temperature and system function.

Pump problems usually work the other way around. They perform better until the oil warms.

 

[lsaami]

Afternoon!

I finally got around to testing hydraulic pressure and it’s right at 2000PSI at my loader valve cold, and 1900ish once the fluid heats up.

Seems like this is a flow issue of some kind. Any advice would be helful.

 

[lsaami]

It won't solve anything, granted, but it might help to know if there is any direct correlation between oil temperature and system function.

Pump problems usually work the other way around. They perform better until the oil warms.

Today, the hydraulics jitter and slow at ambient temp (35F) and by the time fluid gets up to around 50-60F they’re working normally.

 

[Harry in Ky]

1900 PSI is a bit low. As stated earlier it should be more like 2200-2300.

You haven't mentioned whether the "jerky" hydraulics is only with the loader or does it seem to affect the three point or any other hydraulic function? I believe the pressure (supply) line to the loader valve is tapped into the supply for the power steering? I don't think I've ever done it that way, but I wouldn't think it would matter other than the line to that fitting is probably smaller than the main line from the pump going back the lift housing.

I am curious though, when the jerky stuff happens and you try operating the steering while holding a loader valve open do you notice anything different from operating one or the other but not at the same time?

 

[lsaami]

1900 PSI is a bit low. As stated earlier it should be more like 2200-2300.

You haven't mentioned whether the "jerky" hydraulics is only with the loader or does it seem to affect the three point or any other hydraulic function? I believe the pressure (supply) line to the loader valve is tapped into the supply for the power steering? I don't think I've ever done it that way, but I wouldn't think it would matter other than the line to that fitting is probably smaller than the main line from the pump going back the lift housing.

I am curious though, when the jerky stuff happens and you try operating the steering while holding a loader valve open do you notice anything different from operating one or the other but not at the same time?

Steering is also significantly weaker when loader function is slow. 3point is jerky also. All three improve as fluid warms.

Also, test pressure will drop to 1000-1500 if I steer the wheel back and forth during operation. I assume that’s the priority valve trying to keep the pressure routed to the power steering.

 

[Harry in Ky]

I think I would be looking to test the transmission/charge pressure next. I don't know the 2510 system but most models with similar hydraulics require 125 to 150 PSI. I expect there would be a test port on the transmission shift cover.

 

[lsaami]

Well, a few months and some hours on the tractor later, I’m starting to see more hydraulic problems. I rechecked my pressure, and I’ll get 2100 to the six hydraulics at idle, and 2000psi at 2000 engine RPMs.

I tried adjusting the pressure on the pump, and it appears that I have the older style flat blade screwdriver adjustment, and that is maxed out as tight as I can get it.


The new issues developed are this: if I’m operating the loader with a heavy 3 point implement, the implement will drop 2-3 inches or so with the lack of pressure. Then when I stop operating the loader, the 3 point comes back up.

Additionally, if I have the tractor running, in park, and I steer the wheel to the left, the wheels will stop and I’ll lose all hydraulic power and I can hear the pump change tone. No pressure to SCV, loader or 3 point until I turn the steering wheel back to the right. Then everything comes back as normal. It doesn’t do this while the tractor is moving.


I have a good feeling my rock shaft pistons seals are leaking because if I have any weight on the 3 point, they’ll slowly drop immediately after shutting the tractor off. Would leaking piston seals cause all this? That’s a pretty big job for the middle of hay season, but I don’t want to keep going if something is on the verge of failure and risk doing more damage.

 

[buickanddeere]

Well, a few months and some hours on the tractor later, I’m starting to see more hydraulic problems. I rechecked my pressure, and I’ll get 2100 to the six hydraulics at idle, and 2000psi at 2000 engine RPMs.

I tried adjusting the pressure on the pump, and it appears that I have the older style flat blade screwdriver adjustment, and that is maxed out as tight as I can get it.


The new issues developed are this: if I’m operating the loader with a heavy 3 point implement, the implement will drop 2-3 inches or so with the lack of pressure. Then when I stop operating the loader, the 3 point comes back up.

Additionally, if I have the tractor running, in park, and I steer the wheel to the left, the wheels will stop and I’ll lose all hydraulic power and I can hear the pump change tone. No pressure to SCV, loader or 3 point until I turn the steering wheel back to the right. Then everything comes back as normal. It doesn’t do this while the tractor is moving.


I have a good feeling my rock shaft pistons seals are leaking because if I have any weight on the 3 point, they’ll slowly drop immediately after shutting the tractor off. Would leaking piston seals cause all this? That’s a pretty big job for the middle of hay season, but I don’t want to keep going if something is on the verge of failure and risk doing more damage.

The three point hitch should stay up with a load on it . Even with the engine shut down .
It appears that the three point hitch is demanding oil when it should not be . Piston seals , relief valve or control valve .

 

[Tx Jim]

I agree it sounds as if rockshaft piston seals are leaking. That is one of the easier hyd repairs to perform. With 3 pt lowered remove rockshaft piston cover then remove piston. Replace piston seal the replace removed parts. Part #s required are in the photos below.

 

[lsaami]

I agree it sounds as if rockshaft piston seals are leaking. That is one of the easier hyd repairs to perform. With 3 pt lowered remove rockshaft piston cover then remove piston. Replace piston seal the replace removed parts. Part #s required are in the photos below.

will a leaking piston seal cause constant hydraulic draw even with the 3 point all the way lowered?

from what i'm seeing I need the seal and backup ring (#5 and 6) in the second diagram. will i need #9 from the first diagram as well? Looks like some sort of gasket or o ring.