Slow lift

[ch1ch2]

I have a NH 820TL loader that has become very slow lifting very fast lowering, and weak, not wanting to raise anything very heavy.
The arms would not hold in the raised position very long, so I figured the valve might be the problem.
Replaced the valve, now the arms will stay raised for over 24 hours. But, the lift time is still slow. I am not sure if the weight lifting has improved. I think it has but not greatly.

Still have the problem to deal with. I am thinking it could only be one of two things. Cylinders or pump. Both cylinders have leakage from the end cap seals.
Now it seams reasonable to rebuild the cylinders.

Does anyone have any experience with these cylinders?
Are they fairly easy to rebuild?
Any words or advice before I order parts?

 

[texasranger556]

If the loader stays up for 24 hours, the piston seals are probably ok. A little oil dripping out the rod seal isn't going to affect lifting power or speed, just makes a mess.

Have you cleaned the hydraulic suction screen and changed the filter recently? Oil level good? Is the fluid milky?

 

[ch1ch2]

Yes to your 3 questions and disagreement to your assessment of the piston seal based on the loader staying up.

 

[Stimw]

You might have trash from the valve in the hoses.
I would remove each hose end at the cylinder (check for debris) and put end in bucket then work the valve to check flow and remove debris. One at a time.
Also check hose plug ins to be sure they are seated.

 

[Jstpssng]

It sounds like you may have fixed your original problem when replacing the valve; but now you have air in the system. If so it should work itself out if you keep using it.

 

[ch1ch2]

Stimw,
All hoses have been replaced due to another issue, and ends were swapped with the tilt to check valve, then switched back with the problem always staying with the lift cylinders.

Jstpssng,
The lift has been used for months after replacing the valve. Any air would have been self bleed out.

I have seen videos on cylinder repair. There are many types of cylinders and some require special tools. I am looking for someone who has knowledge on the need for special tools and problems I might have before I spend hundreds of dollars on parts only to find out I have to farm out the work.

 

[texasranger556]

Will it hold a heavy load once it's up? Or does it creep down?

Milky fluid could be air or water. Any way water is getting in? If not, could be getting air into the suction side of the pump.

 

[ch1ch2]

I take it you have no experience with these cylinders as my OP.

The answer to your questions I believe were answered in post 1, 2, 3.
No water, Air? The level is full. How could air only get in the lift cylinders an not in tilt cylinders or the 3pt lift? I can't see a leak sucking air against 2500 pounds of pressure.

I do appreciate you trying to help.

 

[texasranger556]

I take it you have no experience with these cylinders as my OP.

The answer to your questions I believe were answered in post 1, 2, 3.
No water, Air? The level is full. How could air only get in the lift cylinders an not in tilt cylinders or the 3pt lift? I can't see a leak sucking air against 2500 pounds of pressure.

I do appreciate you trying to help.

I don't have experience with New Holland cylinders, no. Just John Deere, Kubota, and Chinese log splitter cylinders. You're correct that special tools are needed, it's not brain surgery but it is tricky getting piston seals on without damaging them as you have to heat and stretch them on.

I'm just trying to understand why you believe new piston seals would fix a slow lift/reduced capacity issue when the loader doesn't leak down? Your latest reply is the first you specified WHERE fluid is milky, I assumed your initial "yes" meant reservoir. Sucking air can lead to pump cavitation over time and performance loss, metal damaging your valves, etc.

By all means feel free to rebuild the cylinders, I'm not stopping you...I just think the root of your problem is elsewhere. There are several YouTube videos that you can get an idea what is involved.

You may get more application specific responses posting in the New Holland or hydraulic section of the forum. This one is more for people building stuff. Good luck with the repair.

 

[ch1ch2]

OK
Thank you. I mis-spoke. For some reason I was thinking you asked if I checked for the oil being milky. I mis-read, so the mis-speak.
With your explanation, I see where I made the mistake.

I am glad you have experience with other cylinders, so I think you understand why I am concerned about different cylinders have different designs and different issues. I do not want to get into a cylinder and not know what to do.

Faulty piston seals will not show up with an elevated bucket leaking down. I use to think they would but others here on TBN explained to me why my reasoning was faulty.
If pressure is put on the bucket to lift it, then the leakage of oil from one side to the other would show up.

 

[ch1ch2]

With a bad piston seal oil can leak around the piston and return to tank while attempting to lift because it has a return route through the valve.
When the valve is closed and the bucket is up it can not because the oil has no where to go.
When the valve is closed and the bucket is being forced to lift from outside pressures it can leak around the piston and lift.

The difference being where the oil goes when it is not returning to the tank.

With the bucket in the air the oil has to go from the cylinder side to the rod side.
With the bucket being forced up it has to go from the rod side to the cylinder side.

The bucket can not fall down because in doing so the rod has to also enter the cylinder in addition to the oil, resulting in hydraulic lock.
The bucket can be lifted (with enough force) because in doing so the rod is extending from the cylinder and gives the oil a place to go while also creating a vacuum.

 

[texasranger556]

Ok, I see your point. To test the piston seals I would drop the bucket on a jack, then turn tractor off and relieve pressure by wiggling the loader valve. Disconnect the lift hose quick disconnect. Remove the jack. Hold loader valve in lift position to relieve rod end pressure. Does the bucket drop?

I just hate throwing parts at problems without being completely sure of the issue.

 

[ch1ch2]

I too hate throwing parts at a problem. That takes more money than I have.

In a minute I will be turning off my computer and I will not be able to get back to it for a week to 10 days.
So I do not want anyone thinking I am ignoring them.

 

[ch1ch2]

I am back.

So I guess no one has any experience with the cylinders on a 820 New Holland loader.

 

[davedj1]

Is it possible for you to swap the quick connects from the tilt to the lift? It would tell you right off if it's the cylinders or the valve. Good luck.
Post a pic of the rod end of your cylinder so we can see what it will take to get it apart. As someone said earlier, it ain't brain surgery.
I wouldn't think both cylinder seals would go at the same time but crazier things have happened.

 

[ch1ch2]

Is it possible for you to swap the quick connects from the tilt to the lift? It would tell you right off if it's the cylinders or the valve. Good luck.
Post a pic of the rod end of your cylinder so we can see what it will take to get it apart. As someone said earlier, it ain't brain surgery.
I wouldn't think both cylinder seals would go at the same time but crazier things have happened.

Done (see post 6)

 

[davedj1]

Done (see post 6)

sorry I missed that....

 

[TMGT]

Couple ways to check, remove lift cylinders, extend all the way out, remove rod end hoses only and activate valve to try and extend cylinder. If fluid comes out the the piston seal/s are bad.

You can also do it with the loader chained all the way up or with the loader held down with enough weight to overcome the lift or chained down somehow but its safer to remove the cylinders.

As for rebuilding, I'm not familiar with those particular cylinders but typically all you need is a pick set and some plastic prying tools like what you use for removing interior panels.

 

[ch1ch2]

Couple ways to check, remove lift cylinders, extend all the way out, remove rod end hoses only and activate valve to try and extend cylinder. If fluid comes out the the piston seal/s are bad.

You can also do it with the loader chained all the way up or with the loader held down with enough weight to overcome the lift or chained down somehow but its safer to remove the cylinders.

As for rebuilding, I'm not familiar with those particular cylinders but typically all you need is a pick set and some plastic prying tools like what you use for removing interior panels.

I like the first one. That way will also tell me if it is only one cylinder and how bad it is.
Thanks!

 

[crashz]

Have you checked your pump pressure (did I miss that)?