980h *CAT0980HLJMS04258* bucket issues

[FordL9000]

Got a 2008 980 h with strange bucket issues. Rack and dump seem to want to do whatever they want. The odd time the bucket will work as it should but only for one or 2 scoops. Recently replaced lift pilot solenoid valve, noticed the pigtails for the rest of them were damaged so I replaced all harness ends. The issues where present before doing this work. I don’t think this is an electrical problem however I could be wrong. Seems almost as if the dump spool is sticking.

 

[Mobiltech]

Sounds like the pilot modulation valves are sticking.
You could try cleaning them.

 

[FordL9000]

Sounds like the pilot modulation valves are sticking.
You could try cleaning them.

Are these the same valves that have the solenoids on them aswell?

 

[Mobiltech]

Yes.

 

[Vetech63]

A loose piston on the cylinder rod can have the same symptoms.

 

[FordL9000]

A loose piston on the cylinder rod can have the same symptoms.

The moment the engine is started it curls down / dumps. Hydraulic lock does not stop this issue aswell

 

[Mobiltech]

Could be stuck main tilt spool by the sound of that.
Block the loader arms up, take the cover off over the valves. Remove the tilt spool end cap. The larger cap is the one with the centering spring. See if you can move the spool by hand.
Also make sure the joysticks in cab are centering. If you start it without them centred the machine will usually lockout the hydraulic system so I doubt it’s that.

 

[FordL9000]

Could be stuck main tilt spool by the sound of that.
Block the loader arms up, take the cover off over the valves. Remove the tilt spool end cap. The larger cap is the one with the centering spring. See if you can move the spool by hand.
Also make sure the joysticks in cab are centering. If you start it without them centred the machine will usually lockout the hydraulic system so I doubt it’s that.

To me this is what I think too. I’ve never really worked with spools before so I’ll say i am a little gunshy to play with them

 

[Mobiltech]

If you can you should pressure test the pilot signal to the spool first.

The spool check is pretty simple. Follow the lines from the tilt cylinders into the main control valve to locate the tilt spool. Remove 2 bolts from end cap and pull it off. You will see a big spring capped with an endbolt so it won’t fly out. If you grab the spring you should be able to easily slide the spool out of the valve a bit. Make sure the bucket is blocked up as it will free fall. If it won’t slide out it’s probably jammed with something on the lands.

 

[FordL9000]

If you can you should pressure test the pilot signal to the spool first.

The spool check is pretty simple. Follow the lines from the tilt cylinders into the main control valve to locate the tilt spool. Remove 2 bolts from end cap and pull it off. You will see a big spring capped with an endbolt so it won’t fly out. If you grab the spring you should be able to easily slide the spool out of the valve a bit. Make sure the bucket is blocked up as it will free fall. If it won’t slide out it’s probably jammed with something on the lands.

I should be able to test pressure. Do you know what pilot pressure is on those machines

 

[Mobiltech]

Pilot pressure is 500 psi. You can check each spool supply pressure. There are pressure taps on the lines. There should be 0 pressure at the spool end caps until you move a lever.
Control pressure of the spool will be around 350 at full stroke.

 

[Nige]

Do you know what pilot pressure is on those machines

See the attached.

 

[Mobiltech]

Nige beat me to it.
You can see the test ports for each spool in this pic.

 

[FordL9000]

Hello and sorry for the late response. This problem got put on the back burner for a little bit. However I checked and confirmed pilot pressure it was around that 330-350 range if I remeber correctly. Anyways no dice on any of the solenoids being the issue so I moved to pull the cap off of the spool as you suggested and I found something interesting . I don’t beleive this is normal and definitely could pertain to my issue . Any advice moving forward is greatly appreciated

 

[FordL9000]

The spool to push on is rock solid however I couldn’t remeber if I was supposed to push or pull on it

 

[Nige]

Hmmm. Interesting.
Can you post a better (more in focus) photo of the denris stuck to the magnet please. When the photo is enlarged I can see your fingers perfectly but the debris is out of focus. Try taking a photo with the debris on a sheet of white paper, maybe with a ruler alongside them for scale.

The spool to push on is rock solid however I couldn’t remeber if I was supposed to push or pull on it

You should be able to pull it out slightly with relative ease.

BEWARE: Note the earlier comment by @Mobiltech

If you grab the spring you should be able to easily slide the spool out of the valve a bit. Make sure the bucket is blocked up as it will free fall. If it [the spool] won’t slide out it’s probably jammed with something on the lands.

 

[FordL9000]

Hmmm. Interesting.
Can you post a better (more in focus) photo of the denris stuck to the magnet please. When the photo is enlarged I can see your fingers perfectly but the debris is out of focus. Try taking a photo with the debris on a sheet of white paper, maybe with a ruler alongside them for scale.


You should be able to pull it out slightly with relative ease.

BEWARE: Note the earlier comment by @Mobiltech

 

[Mobiltech]

Hard to tell but did that material come from wear on the end cap itself. The only way it can get into the end cap is from the pilot system. I doubt very much that it came through the solenoid valve.
I would focus on getting the spool to move. Remove the end cap on the opposite end of the spool first then try rotating the spool.

 

[Nige]

Thanks for the new photos. Not definitive but it almost looks as though something has been "shaved off" somewhere. WAG the tilt cylinder piston maybe.?

Were there any reports that the tilt cylinder was drifting on its own when the control was placed in the HOLD position before this control issue started.? Basically for no better reason than the fact that the tilt cylinder is the first thing in line with the control valve spool and that's where any debris would end up. If the spool is jammed by one or more metal particles it would seem logical that they came from the main part of the hydraulic system somewhere.

Maybe remove the end cap from the hoist cylinder section of the control valve and check for debris there also, then check if the hoist spool rotates and moves smoothly back & forth a little.?

I would also suggest to remove the hydraulic filter and cut it open to look for smaller particles. That will give you an idea of how much contamination is circulating in the system.

 

[FordL9000]

Hard to tell but did that material come from wear on the end cap itself. The only way it can get into the end cap is from the pilot system. I doubt very much that it came through the solenoid valve.
I would focus on getting the spool to move. Remove the end cap on the opposite end of the spool first then try rotating the spool.

the cap is scratched up but i tried my magnet on it and i cannot get it to stick so i beleive it is aluminium

Thanks for the new photos. Not definitive but it almost looks as though something has been "shaved off" somewhere. WAG the tilt cylinder piston maybe.?

Were there any reports that the tilt cylinder was drifting on its own when the control was placed in the HOLD position before this control issue started.? Basically for no better reason than the fact that the tilt cylinder is the first thing in line with the control valve spool and that's where any debris would end up. If the spool is jammed by one or more metal particles it would seem logical that they came from the main part of the hydraulic system somewhere.

Maybe remove the end cap from the hoist cylinder section of the control valve and check for debris there also, then check if the hoist spool rotates and moves smoothly back & forth a little.?

I would also suggest to remove the hydraulic filter and cut it open to look for smaller particles. That will give you an idea of how much contamination is circulating in the system.

So the hoist circuit does still work, but i still plan to look into both caps with my new discovery however with the lever for rack and dump in hold the bucket dumps itself so to answer, yes the bucket does drift on its own when the control in the cab is in hold position. as soon as the engine starts