Help me diagnose a hydraulic issue with my loader

[DOCatRU]

Hi folks:

2008 CK 30 with 900 hours. I have put 500 hours on it since purchasing it in 2016.

I use the loader pretty hard, most frequently for lifting pallets of fire wood. Today, as I was moving my first pallet of the season to the house porch I noticed this issue:

I am able to easily lift the pallet to height. With a pallet on the forks, and the engine running I got off the tractor to open my field gate the bucket. At that time the pallet started to slowly tilt forward. The engine was idling when this occurred.

I suspect this may be leaky hydraulic cylinders on the loader. What say ye?

Thanks in advance.

DOC

 

[Leejohn]

See your post.

 

[RickB]

That's the most likely guess.

 

[DOCatRU]

Thanks folks!

 

[Amvcane]

If I recall correctly, the early generation CKs used some plastic parts in the loader joystick. Upgraded to metal in later years.
Something to check before spending any money.

 

[JoelD]

Hmmm, could be a couple things. Seals in cyl for sure or seals in valve body. I’ve replaced both in my backhoe. I wish they sold seal kits for the cylinders.

 

[PILOON]

I lived with that slow leak down FEL syndrome for a long time, just learned to compensate.

Last year I had a hydraulic failure that had me do a thorough overhaul of the front C/S driven hydraulic circuit.
Thinking my pump was shot I opened it to diagnose only to find it A-OK but the shaft was rusty where the seal met it.
I polished that shaft, installed a new seal (used the old one as a back up to prevent crud intrusion)'
Fortunately there was enough space to accept that dual seal mod.

Wow! I can now leave my FEL elevated and 24 hrs later it has not moved. Joy!
(NB: only that one elevated time just 4 testing as one should never do so for safety consideration)

 

[LD1]

It can be the valve or the cylinders with the curl circuit.

Contrary to what some believe....there are NO seals in the valve that can cause this. The valve spools are metal on metal....and thus "some" internal leakage is expected....and most valves have a spec on the amount of fluid per hour at a given pressure.

But no need to get into all that just yet.

First thing.....is this repeatable? Does it happing constantly and continuously Everytime you have a load on? Cause if not....I'd chalk it up to a little piece of debris, or the valve not coming back to perfect neutral and no worry about it any longer.

Second thing to do is isolate the cylinders from the valve. Do this by uncoupling the quick connects.

Once the tractor is at operating temp.....put a load on the forks and take a measurement. Wait a given time, however long it takes to make a measurable/noticable difference. Record movement vs time....

Now repeat the test with the quick couplers unhooked. Now be careful. They are under pressure and won't uncouple and recouple easily. But since you ONLY need to isolate the curl......you can uncouple them with the tractor off and loader on the ground and bled. Then with them unhooked, you simply restart the tractor, raise the loader, and start the timer.

Please report back the results of this simple test.

 

[4570Man]

I’d cycle the curl function a few times and repeat the test and see if happens again. Sometimes a piece of dirt can get in the valve and stop it from seating. If the problem persist I’d move on with the test to isolate the valve from the cylinders.

 

[JoelD]

It can be the valve or the cylinders with the curl circuit.

Contrary to what some believe....there are NO seals in the valve that can cause this. The valve spools are metal on metal....and thus "some" internal leakage is expected....and most valves have a spec on the amount of fluid per hour at a given pressure.

But no need to get into all that just yet.

First thing.....is this repeatable? Does it happing constantly and continuously Everytime you have a load on? Cause if not....I'd chalk it up to a little piece of debris, or the valve not coming back to perfect neutral and no worry about it any longer.

Second thing to do is isolate the cylinders from the valve. Do this by uncoupling the quick connects.

Once the tractor is at operating temp.....put a load on the forks and take a measurement. Wait a given time, however long it takes to make a measurable/noticable difference. Record movement vs time....

Now repeat the test with the quick couplers unhooked. Now be careful. They are under pressure and won't uncouple and recouple easily. But since you ONLY need to isolate the curl......you can uncouple them with the tractor off and loader on the ground and bled. Then with them unhooked, you simply restart the tractor, raise the loader, and start the timer.

Please report back the results of this simple test.

Excellent point on the valve body having no internal seals on the spools. Just inbetween the sections and top and bottom of spools. I’ve replaced every top and bottom seal on all spools. In my case I’ll was making to atmosphere and polling in bottom cups and actuating the cyl once enough oil filled the cup forcing the spill valve up.