New Holland Bucket curl???

[nyone]

You dont need to adjust the pump. You have pressure leaking some where in the valve. It could be a seal between the sections of valve body or just a worn spool. Until you take things appart and check for wear and seal condition theres no adjustment to be made.

 

[macdoesit]

You dont need to adjust the pump. You have pressure leaking some where in the valve. It could be a seal between the sections of valve body or just a worn spool. Until you take things appart and check for wear and seal condition theres no adjustment to be made.

Is valve body and spool the same thing?
I rechecked the lift capacity of the loader and noticed it does not lift as much weight as it used to. A full bucket of firewood was never a problem to lift at any height, now it struggles to get 4' off ground.

 

[jmc]

Too long ago to remember the details but my Dual loader lost "uncurl" force and slowed down. Bought the Dual valve seal kit and fixed it. Seems like I found part of a rubber seal in there. Kit wasn't expensive.

 

[Bentrim]

Usually a valve does not fail unless there has been a foreign object passed thru it and the spool was forced within the body, then the lands of the spool or valve would be broken or scored and allow oil to leak from the load. The main failure of a valve is external leaks or lack of control or centering due to loose linkage or loose or broken centering spring. There are no O ring seals inside the valve. The only O rings keep oil from leaking out of the valve.
Does the loader or bucket leak down? especailly when loaded? If so and you want to check the valve change the bucket and main lift cylinder hoses at the valve, remeber the lift and dump functions will be reversed.
With a load in the bucket and frame raised take a screw driver or piece of pipe place it against the barrel of the cylinder and listen for a hiss as oil is bypassing the piston within the cylinder.

A story from my past. When I was working for a dealer a fellow came in and asked for a pump, Once priced he decided that wasn't the problem. Then he asked for a control valve, again the price was an obsticle. So asked him what he was fixing, he stated his loader was leaking down, Suggested he "listen" to the cylinders. Yes a cheap packing kit fixed the dropping problem.
Almost forgot to say remember a pump does NOT make pressure it only moves fluid. The pressure is created by applying a resistence to flow.
A failing pump leaks internally and cannot maintain "as new" flow therefore the volume of oil and depending on wear the ability to produced needed pressure will be problem.
The control valve should also contain a relief valve to keep system pressure to a safe level, usually you can hear it if it bypasses. The control valve may also contain load checks, these are check valves to prevent a load from dropping until system pressure is more than the load.

 

[nyone]

Is valve body and spool the same thing?
I rechecked the lift capacity of the loader and noticed it does not lift as much weight as it used to. A full bucket of firewood was never a problem to lift at any height, now it struggles to get 4' off ground.

Yes and no. The valve body is typicaly multi sections of valves that hold the spool valve. The spool valve is the round pieces of steel that you physically move by moving the loader handle.
They have lots of seals and or very tight tolerances so any wear can make hydraulics do odd stuff.

 

[macdoesit]

Usually a valve does not fail unless there has been a foreign object passed thru it and the spool was forced within the body, then the lands of the spool or valve would be broken or scored and allow oil to leak from the load. The main failure of a valve is external leaks or lack of control or centering due to loose linkage or loose or broken centering spring. There are no O ring seals inside the valve. The only O rings keep oil from leaking out of the valve.
Does the loader or bucket leak down? especailly when loaded? If so and you want to check the valve change the bucket and main lift cylinder hoses at the valve, remeber the lift and dump functions will be reversed.
With a load in the bucket and frame raised take a screw driver or piece of pipe place it against the barrel of the cylinder and listen for a hiss as oil is bypassing the piston within the cylinder.

A story from my past. When I was working for a dealer a fellow came in and asked for a pump, Once priced he decided that wasn't the problem. Then he asked for a control valve, again the price was an obsticle. So asked him what he was fixing, he stated his loader was leaking down, Suggested he "listen" to the cylinders. Yes a cheap packing kit fixed the dropping problem.
Almost forgot to say remember a pump does NOT make pressure it only moves fluid. The pressure is created by applying a resistence to flow.
A failing pump leaks internally and cannot maintain "as new" flow therefore the volume of oil and depending on wear the ability to produced needed pressure will be problem.
The control valve should also contain a relief valve to keep system pressure to a safe level, usually you can hear it if it bypasses. The control valve may also contain load checks, these are check valves to prevent a load from dropping until system pressure is more than the load.

With a load in the bucket and lift up several feet it does not bleed off over night.

 

[macdoesit]

View attachment 1970651View attachment IMG_20241207_133501228_HDR - Copy.jpg

 

[Bentrim]

Yes and no. The valve body is typicaly multi sections of valves that hold the spool valve. The spool valve is the round pieces of steel that you physically move by moving the loader handle.
They have lots of seals and or very tight tolerances so any wear can make hydraulics do odd stuff.

All loader valves that I am familiar with are made as the attachment explaines.

Model BA - 2 Spool Parts | Cross Mfg.

Parts Include – 3 or 4-Way Spool, Handle, Load Check, Pin Kit, Relief Assembly, Rubber Grommet, SAE PlugSeal Kit, Spool Seal, Spring, Valve Housing

crossmfg.com

Note there are no internal seals and only O rings to keep the oil in the valve --- better than dripping down your pant leg and into your shoe---- If you look at # 2 in the diagram note the multiple circles arond the center lands of the spool They help the oil seal between the internal lands of the valve, no O rings needed. note 17 and 23 are only used at the ends of the spools Those spools are usually select fit and are usually not interchangeable.
Most loader valves are monoblock -- fancy word for one piece -- and have two spools in one block although they can be purchased single spool and three spool.
A backhoe usually uses a sectional valve with single sections stack together to get the number of curcuits required.
A valve can be activated by a lever, or a lever controlling the valve thru a cable, or electrical solenoids.
When I played with farm machinery the combines used a valve very similar to this except it used a plastic poppet to keep the load from changing. That was until the controlled the header height by an electric controlled valve.

 

[macdoesit]

You are way over my head. I have never worked on a spool before.

 

[macdoesit]

I read your post as bucket not lifting tractor, but loader is limp or floating; got it.
Since it won't stay in float, is it possible the spool has some broken parts in the end cap?
Other question is does the loader hold in position when it is raised off of the ground?

Spool valve is good. I switched the hydraulic connections from the boom to bucket and the boom arms still will not stay down when curling the bucket, and the curl is still strong on the boom connections. It must be boom hydraulic cylinders need rebuilt. Seems odd that both cylinders go bad at the same time????