JD 2640 hydraulic issue

[Bristol121]

So a few years ago I purchased this gem. Mechanic inclined but not much on tractors. Auto engines trans restore ect my backround


1984 2640 with reverser

So this thing was a rattle box. Loud noisy in gear box. Did some trouble shooting and thought possibly clutch was bad and possibly trans pump. Spilt tractor at clutch, replaced everything, clutch set up by local dealer. Replaced clutches and seals in reverser and front drive. Split again replaced all o rings and seals and trans pump.

Finally ran it yesterday. Good news is its quiet. Bad news I still have a hydraulic problem. But not as bad as before. Basically I will loose hydraulic function after it gets hot. I did not have loader on it yesterday to run it through it paces hard but ran the gravel box on driveway for prob 45 minutes at about half throttle in 5th gear. The three point still shuttered two times. Didnt loose hydraulic. But the three point basically rattles up and down in a quick fashion.

There is a barking noise and seems like still a possible starvation or cavitation or main pump is the real problem.

Would like any thoughts as to what to check. I didnt have my gauge hooked to the main pressure yesterday and I probably should have.

 

[Tech 7]

It sounds like a high pressure leak to sump but there is no warranty on diagnostics from this distance. Easiest to check and a fairly common issue is leaking rockshaft
valves. With tractor running, remove hydraulic oil fill cap and look toward the top and front of the rockshaft housing. An oil spray or stream indicates a leak. The
repair involves removing rockshaft and valve. If not leaking there it could also be an SCV or steering leak.

 

[hedgeless_horseman]

You just gave me an idea. Several years ago I bought a $25 USB flexible endoscope camera thingy for cell phone. I am going to try to remember to use that to try to see inside areas of the tractor like rockshaft via access port, hydraulic brakes and rear seals via bleeder, clutch via access port, etc.

DEPSTECH USB Endoscope Camera 720P Borescope 5.5mm Snake Inspection Camera
https://www.ebay.com/itm/284310567714

 

[Bristol121]

(quoted from post at 09:21:52 05/26/22) It sounds like a high pressure leak to sump but there is no warranty on diagnostics from this distance. Easiest to check and a fairly common issue is leaking rockshaft
valves. With tractor running, remove hydraulic oil fill cap and look toward the top and front of the rockshaft housing. An oil spray or stream indicates a leak. The
repair involves removing rockshaft and valve. If not leaking there it could also be an SCV or steering leak.

I have done as you said before the whole year down. I checked and eliminated the steering. In the rocker box I see a mist floating in the air. No streams. Today I had to do some more rip off and repair as a chunk of casting ventured its way into the spool valve for the reverser

So after repairing that. I started and had gravel box off the ground about a foot testing the reverser. Then box dropped out of nowhere and pump squall. So Im intermittent believing rocker shaft issue as well at this point. I guess I need so see if I can make it do it while looking in the hole.

Thanks for the tips

Edit

So I just went and played with some more I can get to do it on command pretty much. If I pull the three point lever slow it raised the box fine no issue. If I cram it back in a hurry I can hear the motor load slightly. One raised I can continue to hear the load on the engine after 30 seconds it starts to shutter then drops. I can see some hydraulic leaking on right side when it does this but I would not call it a spray. There is definite fine mist and looks like a smoke rolling from the cap hole. So maybe a pressure relief valve issue?

This post was edited by Bristol121 on 05/26/2022 at 01:04 pm.

 

[Bristol121]

So after about 5 hours of trying to get the arms off the rocker shaft I was able to take a peak at things.

My book lists pressure and return valves held open, piston o ring failure, defective thermal relief valve, leaking return valve.

From what I can gather those two valves are the ones in the cylinder housing. Pulled them apart and the o rings are MIA on the plugs. They also didnt seem sticky. But hoping this is the issue. I see they make a sleeve to replace the bores on the cylinder. Anyone ever done that?

I dont mind replacing everything I can while in here. Dont like to do it twice. [/img:f8b91af128]

 

[Tx Jim]

Welcome to YT
Sounds as if you located some of your tractors hyd problem. I've never seen RS piston bore faulty enough to require installing a sleeve but there's always a 1st time for everything. I'd install new piston seal & determine that it wouldn't hold before installing a sleeve. I have seen several RS control valve seals AWOL.

I suggest after reassembly of RS housing on trans case to follow the ""several steps outlined in tech manual"" about adjusting L/D control mechanism assembly.

When using box blade do you have lever under seat set in "D position"?

 

[Bristol121]

(quoted from post at 04:11:04 05/28/22)
Welcome to YT
Sounds as if you located some of your tractors hyd problem. I've never seen RS piston bore faulty enough to require installing a sleeve but there's always a 1st time for everything. I'd install new piston seal & determine that it wouldn't hold before installing a sleeve. I have seen several RS control valve seals AWOL.

I suggest after reassembly of RS housing on trans case to follow the ""several steps outlined in tech manual"" about adjusting L/D control mechanism assembly.

When using box blade do you have lever under seat set in "D position"?

I should of stated better. The sleeves Im referring to are for the valve bores not the piston bore. Piston bore looks ok. Few scratches but I think it will be ok.

If your asking about the load sensing lever. I dont know what letter but I had it in hhe all the way down position

 

[Tx Jim]

I don't remember ever needing to replace RS control valve sleeves but @ $21.61 each they're not real expensive in today's part prices

 

[Bristol121]

(quoted from post at 11:58:29 05/28/22)
I don't remember ever needing to replace RS control valve sleeves but @ $21.61 each they're not real expensive in today's part prices

I ordered them. I just have no idea how to go about getting them out.

 

[Bristol121]

Ok well I m back to square one lost all hydraulics again

To recap. I ve replaced the clutch, pressure plate, front drive clutch, reverser clutch, all the o rings for the tubes, trans pump, rebuilt rocker everything thing that was replaceable.

So everything worked fine. I solved my 3 point problem and added a second SCV. Went out with box blade a few times and no issues

Put loader on yesterday. And it was ok for 5 minutes. Then loader bucket was a little weird on bucket dump. Had to cycle lever a few times. To dump. I was in sandals and shorts. I could tell it was getting hot as I could feel on my legs. Then lost everything again.

What I am thinking is that there may be an issue possibly with the loader controls bypassing oil. And causing issues. And or it is heating the oil enough that there is a thermal bypass.

Any thoughts?

 

[Jim.ME]

The load sensing lever was mentioned in an earlier post. "D" is up, "LD" is center, and "L" is down. You can download a free copy of the Operator's Manual at https://techpubs.deere.com/

Do you know if your loader control valve is for a closed center system? If it has a conversion plug the seals on it could be leaking. If it has an adjustable relief valve that should be cranked down hard so it won't relieve pressure; the tractor's relief valve must control system pressure.

 

[Tx Jim]

If loader has an independent control valve disconnect loader control valve return hose from tractor & cap hyd fitting on tractor. With loader control valve levers in neutral no oil should exit open valve return hose when engine is operating. If loader valve has a relief valve I suggest to turn adjusting screw clockwise to fully close the relief valve.

 

[Bristol121]

As far as load control. You are referring to the rock shaft load control? I have the later serial number I have 5 positions I think. Min on top and max on bottom. Min holds 3 point in position. Max allows float.

I ran for a few hours with box blade. Didn t notice the heat. Or sounds of lack of oil. With no loader on. But in total putting loader on and using hydraulics on loader to line up bolts then som work was in total about an hour with loader hooked up. 3 point then became chattery as well as loader. Then lost everything. Reving it up came back momentarily.

The loader is a 158 with the controls on the mast on right side of loader bracket. I believe it is the Cessna valve part AW20889. Two lever valve



Don t quote me on this as I am not there to look. Feed and return are under tractor right side under axle. The return t s into filter housing and feed comes off another line. Can t remember from what though.

This post was edited by Bristol121 on 07/12/2022 at 06:29 am.

 

[Tx Jim]

JD model 158 was designed for row-crop not utility tractor. I can't even envision how far out in front of fuel tank bucket attaching pins are located on a JD utility tractor with a 4 cyl engine. AW20889 was designed for closed-center hyd system & was not convertible to open-center. I still recommend performing the test by removing return line from tractor & operating engine with FEL control levers in neutral

This post was edited by Tx Jim on 07/12/2022 at 07:19 am.

 

[buickanddeere]

Does the remaining hydraulics work with the rock shaft control in the lowest position ?

 

[Bristol121]

(quoted from post at 07:16:50 07/12/22) JD model 158 was designed for row-crop not utility tractor. I can't even envision how far out in front of fuel tank bucket attaching pins are located on a JD utility tractor with a 4 cyl engine. AW20889 was designed for closed-center hyd system & was not convertible to open-center. I still recommend performing the test by removing return line from tractor & operating engine with FEL control levers in neutral

This post was edited by Tx Jim on 07/12/2022 at 07:19 am.

I told you this thing is an abomination lol. After you mentioned I did some searching on loader sizes and yes now realize it is not the right one. Who would of thought some farmer would of thought it was a good idea lol. It doesn t look that funky I guess but makes sense. 30" more reach from what I can gather. But looking at 146 loaders on tractors doesn t seem that different. I will try the line in a bucket when I get home later in the week.

I tried to find dimensions comparing the two models but no avail. I don t know if the front of mine has been shortened but it definitely has been patched and welded.

As far as the other gentleman who posted. I have only had the load lever all the way down aka float mode never needed to run the other way. As far as position of the rock shaft lever. I guess I don t know for sure but don t think it matters in this instance as I believe it has happened both ways.

And thanks tx- Jim for all the help.

 

[Bristol121]

(quoted from post at 07:16:50 07/12/22) JD model 158 was designed for row-crop not utility tractor. I can't even envision how far out in front of fuel tank bucket attaching pins are located on a JD utility tractor with a 4 cyl engine. AW20889 was designed for closed-center hyd system & was not convertible to open-center. I still recommend performing the test by removing return line from tractor & operating engine with FEL control levers in neutral

Started cold. Took a second or two but hydraulics came back.

So I took the return line off. And without moving controls I had a steady flow of hydraulic out of return line. Maybe something along lines of a gallon after 2-3 minutes give or take. I imagine when it gets hot is when it would cut loose.

And with the 158 loader the lower bucket pin is 48" from center of front axle. Good news is it has the "heavy duty" straight adjustable front axle.


Edit.
Went back out an compared to pictures on internet. Looks the same as a 146 on a 2640. Lift cylinders have stamping of aw18444. Which appears to me it’s a 146 is 158 clothing. Measuring from rear boom pin. To upper bucket cylinder mount is 62-1/2 center to center.

This post was edited by Bristol121 on 07/14/2022 at 02:48 pm.