JD 3020 lost steering and 3 pt lift

[donaldposterick]

Hi everyone,

I have a 1971 (151xxx serial number) synchro shift JD 3020, which I was out running a brush mower with the other day, and had parked it for about an hour to pick some rocks, and when I came back and started it up, it seemed like there was no hydraulics. Steering was extremely difficult, and only wanted to turn left, and no 3 point lift. Had to start and stop it to get it to turn right enough to get it back out of the field. Steering feels pumpy and difficult to the left, and it won't turn past center to the right now at all (on or off), and no 3 pt lift. Hydraulic fluid was a towards the bottom of the fill line, so I topped it off and still no change. Not sure where to start at for troubleshooting this machine. We tried bleeding the steering, and it didn't seem to have any air trapped in it.

 

[wore out]

Hi everyone,

I have a 1971 (151xxx serial number) synchro shift JD 3020, which I was out running a brush mower with the other day, and had parked it for about an hour to pick some rocks, and when I came back and started it up, it seemed like there was no hydraulics. Steering was extremely difficult, and only wanted to turn left, and no 3 point lift. Had to start and stop it to get it to turn right enough to get it back out of the field. Steering feels pumpy and difficult to the left, and it won't turn past center to the right now at all (on or off), and no 3 pt lift. Hydraulic fluid was a towards the bottom of the fill line, so I topped it off and still no change. Not sure where to start at for troubleshooting this machine. We tried bleeding the steering, and it didn't seem to have any air trapped in it.

Do you know if there happens to be a "manual destroker" installed on the hydraulic pump? IF so, destroke it, run the engine to flush out any debris that may have gotten into the pressure control valve, then put it back into stroke and see if anything changes.

Whether or not the hydraulics "come back" after that, check/change the hydraulic filter and the sump screen and note if there's significant metal or brake debris in them.

A few things to get you started on figuring what's going on!

 

[donaldposterick]

Do you know if there happens to be a "manual destroker" installed on the hydraulic pump? IF so, destroke it, run the engine to flush out any debris that may have gotten into the pressure control valve, then put it back into stroke and see if anything changes.

Whether or not the hydraulics "come back" after that, check/change the hydraulic filter and the sump screen and note if there's significant metal or brake debris in them.

A few things to get you started on figuring what's going on!

No destroker on the top of the pump, just the two plugs. Is it possible that the destroker is on the bottom? There is a bolt/plug with an inner bolt that can be moved.

Will check the filter and sump screen tomorrow. We just changed it recently so I suspect it'll be clean

 

[Tx Jim]

Screw with lock nut under bottom of front hyd pump is adjustment for stroke control valve. This screw location should not be changed without monitoring hyd stand-by pressure. After you check hyd filter & check hyd sump screen I suggest to check frt hyd pump coupler when engine crankshaft is rotating to be sure pump shaft is also rotated IE coupler is not stripped out.

 

[tim s]

Possibly the pump drive shaft splines have stripped out and the pump is not turning,, it's a bit hard to see if the pump shaft is spinning since it is nearly out of sight

 

[donaldposterick]

Pump is turning good, shaft when I opened the bleeder valve yesterday under the dash for the steering it had a steady flow. Wasn't fast, but seemed consistent without air. Hydraulic filter was fine, as clean as when we put it in. Haven't removed the sump screen yet. Need to find a bucket for catching the oil. Is the sump screen before or after the filter? We were wondering if it would be dirty if the filter is clean? Also we lifted the front end of the tractor and it'll turn to the left, but not to the right with the engine off. Not sure if this is related to any potential issues we are facing right now.

 

[ET]

Do you have brakes? There may be something stuck in the stroke control valve that's holding it open.

 

[donaldposterick]

Screw with lock nut under bottom of front hyd pump is adjustment for stroke control valve. This screw location should not be changed without monitoring hyd stand-by pressure. After you check hyd filter & check hyd sump screen I suggest to check frt hyd pump coupler when engine crankshaft is rotating to be sure pump shaft is also rotated IE coupler is not stripped out.

Checked the filter and sump screen. Both were clean.

 

[Tx Jim]

I suggest to check hyd stand-by pressure which should be 2250-2350 psi & install/utilize destroking screw.

 

[donaldposterick]

I suggest to check hyd stand-by pressure which should be 2250-2350 psi & install/utilize destroking screw.

I'll order some hydraulic gauges, and the parts for the destroking screw. Do you know what size couplings are used? The service manual references obsolute part numbers and doesn't call out the actual size. I was looking at this kit from amazon.

Hydraulic Pressure Test Kit, 5 Gauges (10/100/250/400/600bar) Max 10000psi / 60mpa 13 Test Couplings 14 Tee Connectors 5 Test Hoses w/Sturdy Portable Carrying Case for Excavator Construction Machinery https://a.co/d/c9ciGTp

 

[wore out]

I'll order some hydraulic gauges, and the parts for the destroking screw. Do you know what size couplings are used? The service manual references obsolute part numbers and doesn't call out the actual size. I was looking at this kit from amazon.

Hydraulic Pressure Test Kit, 5 Gauges (10/100/250/400/600bar) Max 10000psi / 60mpa 13 Test Couplings 14 Tee Connectors 5 Test Hoses w/Sturdy Portable Carrying Case for Excavator Construction Machinery https://a.co/d/c9ciGTp

Where are you intending to check pressure(s)/connect the gauges? That will determine what fittings are needed.

I don't think there's much in that kit directly compatible with the fittings DEERE used in the 3020 era.

 

[donaldposterick]

Where are you intending to check pressure(s)/connect the gauges? That will determine what fittings are needed.

I don't think there's much in that kit directly compatible with the fittings DEERE used in the 3020 era.

Where would you recommend?

 

[Tx Jim]

I agree with wore out. I order to check 3020 with Syncro-range trans hyd system pressures one needs 2 gauges. A 5000 & 300 psi gauge with a hose. 5000 psi hose needs a male breakaway tip to attach to rear breakaway coupler. 300 psi gauge with hose is smaller fitting but I can't remember exact size

 

[Tx Jim]

Where would you recommend?

Surplus center or Bailey Hyd's for gauges, hoses & fittings

 

[donaldposterick]

Surplus center or Bailey Hyd's for gauges, hoses & fittings

I'll get some ordered, and then next week I should be able to do some more diagnostic. Another question, so I was reading in the service manual that even when the hydraulics aren't working properly, the steering is supposed to work manually, but on my machine It's stuck to the left half. I can't turn the wheel straight. It's like it's dead-headed or running out of travel like 5 degrees to the left of center. It'll manually turn left all the way fine, but I can't turn the wheel straight or to the right at all. Is this related to the hydraulics not working or any indication of a problem? I was thinking it was air in the system, since the fluid was a little low, but I tried bleeding it from below the dash and didn't have any air come out, just oil.

 

[wore out]

I'll get some ordered, and then next week I should be able to do some more diagnostic. Another question, so I was reading in the service manual that even when the hydraulics aren't working properly, the steering is supposed to work manually, but on my machine It's stuck to the left half. I can't turn the wheel straight. It's like it's dead-headed or running out of travel like 5 degrees to the left of center. It'll manually turn left all the way fine, but I can't turn the wheel straight or to the right at all. Is this related to the hydraulics not working or any indication of a problem? I was thinking it was air in the system, since the fluid was a little low, but I tried bleeding it from below the dash and didn't have any air come out, just oil.

Find out why the hydraulics quit working and get that repaired, then check the power steering.

(I don't think anything except a VERY unusual failure in the steering valve would cause the hitch hydraulics not to get pressure/flow.)

 

[donaldposterick]

Ok, just was wondering if the hydraulics could cause even the manual steering to lock up like it is? Right now it's extremely difficult to move around, that's why I was wondering.

 

[donaldposterick]

I agree with wore out. I order to check 3020 with Syncro-range trans hyd system pressures one needs 2 gauges. A 5000 & 300 psi gauge with a hose. 5000 psi hose needs a male breakaway tip to attach to rear breakaway coupler. 300 psi gauge with hose is smaller fitting but I can't remember exact size

I had zero pressure on the rear couplers when activating them. Where should the other measurement be taken?

Also, I noticed that the 3 point would lift when first starting, but very very slowly. Then once it's running it will drop but not lift again. Is this a sign of the front pump going out? Is there any ports or places I can measure the output of the pump directly?

 

[donaldposterick]

Here's how I tested the pressure in the rear, I tried all the ports and didn't get any pressure while activating them.

 

[Tx Jim]

I suggest to check pressure in at or front of pressure control valve. Also with hyd filter cover removed, clean container to catch any oil rotate engine crankshaft for 15 seconds then measure hyd oil in the container