Loader Joystick - Bucket goes down when trying to lift

[RickB]

Here's a marked pic of the valve ptsg posted of the valve you may have. The load checks are circled. Disassemble them, check for collapsed springs and debris in the ball/seat area.
I bet the guy you called offered to sell you a new valve?

 

[dm-in-mn]

Here's a marked pic of the valve ptsg posted of the valve you may have. The load checks are circled. Disassemble them, check for collapsed springs and debris in the ball/seat area.
I bet the guy you called offered to sell you a new valve?

ptsg posted the same diagram in post #6 on this thread. I explained in post #13 that my valve is different than the one in the parts diagram from the M1000 loader. Mine appears to be a Koyker loader valve made by Pace Manufacturing. Thank you for the suggestion, however. I cannot find a parts diagram for the loader valve I have.



Edit:
The gal I spoke to actually suggested dropping it off at a local hydraulics shop to have them look at it. I'm stubborn and prefer to DIY, however. But that is also a possibility. I'm just afraid they are going to be 5 weeks out before they can even look at it, leaving my tractor unusable in the mean-time.

Edit2: spelling errors

 

[npalen]

Some good information in this thread! I might reiterate that bad piston seals CAN cause loader arms to drift down over time if there is leakage past the valve spool due to normal manufacturing tolerances as mentioned. I was lucky in that the valve used on my Westendorf TA-111 loader has zero leakage and will hold the loader in a raised position indefinitely. (I know that's against TBN rules)

I compliment the OP on the excellent pictorial shown in the first post of the thread. The old adage "a picture worth a thousand words) certainly applies in helping everyone understand what is in the "thousand words".

 

[RickB]

ptsg posted the same diagram in post #6 on this thread. I explained in post #13 that my valve is different than the one in the parts diagram from the M1000 loader. Mine appears to be a Koyker loader valve made by Pace Manufacturing. Thank you for the suggestion, however. I cannot find a parts diagram for the loader valve I have.



Edit:
The gal I spoke to actually suggested dropping it off at a local hydraulics shop to have them look at it. I'm stubborn and prefer to DIY, however. But that is also a possibility. I'm just afraid they are going to be 5 weeks out before they can even look at it, leaving my tractor unusable in the mean-time.

Edit2: spelling errors

A photo of a Pace 7040 replacement valve listed for Koyker loaders shows a single plug on top and bottom of the valve casting between the valve spools. If your valve has these plugs I encourage you to remove them and inspect the parts within. There's a very high probability they are load checks.

Oem replacement hydraulic loader valve for koyker the best Amazon price in SaveMoney.es

Oem replacement hydraulic loader valve for koyker front end loaders - koyker loa searched at the best price in all stores Amazon

savemoney.es

 

[dm-in-mn]

Problem may be solved! See below

A photo of a Pace 7040 replacement valve listed for Koyker loaders shows a single plug on top and bottom of the valve casting between the valve spools. If your valve has these plugs I encourage you to remove them and inspect the parts within. There's a very high probability they are load checks.

Oem replacement hydraulic loader valve for koyker the best Amazon price in SaveMoney.es

Oem replacement hydraulic loader valve for koyker front end loaders - koyker loa searched at the best price in all stores Amazon

savemoney.es

That gave me the confidence to just start taking stuff apart.




On the back of the valve body is this large feature with a flat-head slot in it. I was afraid this would be in there so tight I wouldn't be able to get it. Not the case. It was barely torqued down at all. The other two features with the Alan/Hex heads appeared to just be ports (I took those out first)

Yep, it's definitely a check valve.

Right away I noticed two distinct shiny high-spots, rather than uniform wear.

So I lapped the face down with 800 grit, followed by 2000 grit sand paper. I should have fixture this, as I don't think I lapped it perfectly perpendicular by hand. If I need to do this again, I will chuck the plunger up in a drill press (without turning the drill press on), and use the quill for steady/square down-force. Then I will move the sand paper by hand.

Here it is all shined up.

After this was re-installed, I started the tractor up and gave it a try.
MAJOR IMPROVEMENT

There is still the slightest drift upon joystick engagement, and I think this is due to my inability to lap the plunger perfectly perpendicular by hand. I discussed a possible solution to this above the fourth picture above. I have yet to test the improvements when lifting something heavy, but lapping the check valve plunger has made a substantial improvement to the drift without a load. I will do my best to report back after I have a change to thoroughly test under load.

I compliment the OP on the excellent pictorial shown in the first post of the thread. The old adage "a picture worth a thousand words) certainly applies in helping everyone understand what is in the "thousand words".

Thank you. I am most certainly a visual learner, and inherently a visual explainer. I have a feeling that most of us lurking here are the same.








Edit: Struggling with attachments

 

[ptsg]

Good job troubleshooting this issue.

On the picture with the sand paper, looks like there is some scoring on the outside diameter? That would probably cause the plunger to hang open as it looks like that style of check valve uses the plunger sliding on a tight bore.

 

[RickB]

I'll put the abrasive on a piece of glass and dress the part by moving it across the stationary abrasive sheet. That gives a flat, uniform surface.
In this instance I agree the sides of the poppet must be pristine.

 

[npalen]

I would think that running the spindle with the part chucked in a lathe or drill chuck would stand a better chance of keeping the end square when lapping. The part would have to run true, however. No runout.