Bucket weak

[Keel74]

I have an old JD 1020 diesel with a closed hydraulic system. It has a 37 loader on it and it had been hesitating while raising. The fluid is full. I use it to lift the tounge on my camper and move the camper. However, recently it wouldn’t raise and was having difficulty raising with nothing in it. The cylinders on it are one way cylinders. I had them rebuilt and they work great but it still won’t lift the tounge on the camper, it just squats the tractor. Doesn’t make any sounds just won’t lift it like it used to and it would lift it with ease before. Is there anywhere I can adjust the pressure?

 

[38 Sears Roebuck]

How about your filters?

 

[Keel74]

How about your filters?

Yeah, I’m gonna change but it doesn’t have 100 hours on it since I changed it last.

 

[Roger in Iowa]

You rebuild one way cylinders if they are leaking. What would be the reason to rebuild to increase lifting. You need to be looking at pressure problems!

 

[Keel74]

Come on man, positive feedback only please don’t criticize. The cylinders wouldn’t raise part of the time and as soon as I shut it off they would drop to the ground so I know they were bysssing fluid.

 

[jdeere562]

Why would the tractor squat, if the cylinders are not applying upward pressure? That part makes no sense to me.

 

[Steve in VA]

Come on man, positive feedback only please don’t criticize. The cylinders wouldn’t raise part of the time and as soon as I shut it off they would drop to the ground so I know they were bysssing fluid.

You changed the filter but what about the screen? My 1020 gasses had similar issues and the screen was crud.

 

[Keel74]

You changed the filter but what about the screen? My 1020 gasses had similar issues and the screen was crud.

Screen was good too but that was a couple years ago. I’m going to drain the fluid and see what it looks like now. Thanks.

 

[Tx Jim]

How many hrs since hyd oil suction screen was checked/cleaned. I suggest to check stand-by pressure which should be 2250-2350 psi. Stand-by pressure can be raised by turning screw under bottom of pump in while monitoring hyd gauge.

 

[Roger in Iowa]

Come on man, positive feedback only please don’t criticize. The cylinders wouldn’t raise part of the time and as soon as I shut it off they would drop to the ground so I know they were bysssing fluid.

No the cylinders are not bypassing fluid! If they were you would have leaks from the rod end of the cylinders.
Your control valve is leaking back to the reservoir allowing the bucket to lower!

 

[Jim.ME]

Come on man, positive feedback only please don’t criticize. The cylinders wouldn’t raise part of the time and as soon as I shut it off they would drop to the ground so I know they were bysssing fluid.

The OEM one way cylinders on a JD 37 loader are displacement cylinders. As oil is forced into the barrel the rod is pushed out lifting the arms. There is no piston with packing on the rod of that type of cylinder. It can't bypass internally. There either has to be an external leak (hose, fitting, or gland packing) showing or the control valve is worn and not holding.

Slow raising maybe the screen. Not holding is likely in the valve unless there is visible oil running out of it.

 

[Steve in VA]

Screen was good too but that was a couple years ago. I’m going to drain the fluid and see what it looks like now. Thanks.

Keep us up on follow up

 

[Roger in Iowa]

Why would the tractor squat, if the cylinders are not applying upward pressure? That part makes no sense to me.

Squat is not a measureable force.
Hydraulic pressure is. Sounds like hydraulic pressure is not as high as it was previously.

 

[Keel74]

Screen was good too but that was a couple years ago. I’m going to drain the fluid and see what it looks like now. Thanks.

Yes, the guy told me there was no piston in there to bypass but something about the seals and o-ring. All I know is before, they would drop right after I shut off the tractor. And now they hold firm. I cleaned the suction screen about 70 hours ago. I tried to attach a video but it was too big.

Squat is not a measureable force.
Hydraulic pressure is. Sounds like hydraulic pressure is not as high as it was previously.

Thats what I thought. I haven’t touched anything else. Do you know the process for increasing the hydration pressure?

 

[Jim.ME]

Do you have a gauge to check the pressure as Tx Jim suggested? It is best to know what you have before thinking of adjusting. JMHO

I am wondering if the spool of your control valve is moving and centering properly.

 

[Keel74]

Yeah I had a pressure gauge on it and it had good pressure according to what you had put in here.

 

[Jim.ME]

Is your loader operated by a separate loader valve?

 

[Keel74]

Is your loader operated by a separate loader valve?

The hoses come off the scab and return behind the driver’s seat.

 

[Keel74]

Not scab. SCV

 

[Tx Jim]

Please post a photo of your FEL control valve. It's possible your FEL control valve is a factory installed control that it has a relief valve that is not holding 2250 psi. Correct location for FEL control valve return hose is to a ported hyd cover as shown in photo below. JD offered 2 different style ported filter cover & the cheaper version is part # L55982. Pressure for FEL should be Teed in behind pressure control valve utilizing fitting key 13 & #21. https://partscatalog.deere.com/jdrc/sidebyside/equipment/3593/referrer/navigation/pgId/1755817