Backhoe dipper stick lifting on its own

[JoelD]

I all I posted similar on Kioti forum
My dipper stick is rising on its own
The joystick, concurrently moves on its own.
It will get to the point where it is fully engaged and motor lugs and loader looses power as dipper ram has hit stop but joystick is in full up position and I'm hitting relief I'm sure.

Then takes a bit of force to push joystick to down position and then to detent. Backhoe then works normally and lever moves freely

Then if I don't operate backhoe it starts all over again and within a minute or two I'm back to full up position

I have external leak from bottom of dipper spool valve


I've replaced o-rings on just about all of the spool valves including dipper

I'm pulling apparat again today and looking for help in what I should be looking for

I'm at a loss

Joel

 

[LD1]

Sounds like you got something going on in the can on the end of that valve spool.

Assuming when you push the lever to raise the dipper....it is actually pulling up on the spool. If you have a leaking spool or casting that is leaking into the can area, hydraulics could be pushing that spool up and thus moving the dipper. With the can full of oil it would be hard to return the control stick to neutral.

But most cans have a weep hole in them to prevent this. Perhaps the weep hole is blocked?

 

[SSdoxie]

Agree with LD1.
Anther place that will allow oil in that cap besides the seal is through/around the screw holding the centering spring detent assembly to the spool. A valve spool with float is drilled through the center to connect work ports is float position, then the drill end is plugged with the screw holding the spring assembly. If that screw is loose take it out, clean and dry the spool threads then apply some thread sealant (Loctite) and let it cure before using it.

 

[JoelD]

Will be pulling today will go through all that's been stated so far thanks guys!!

Sincerely
Joel

 

[JoelD]

OK, pulled apart and looks like i sorted, thanks for all the help guys!

I pulled the spool all the way out.

Problem was oil getting past the o-ring on the bottom of the spool.

When I pull apart I have a plate that slides over the end of the spool, it has an o-ring and a plastic wiper washer. It was that o-ring that was leaking. The plate has an o-ring between it and the body, I replaced that black o-ring. Then there's an o-ring within the plate that seals against the spool. That was the bad one.

You must purchase as a set with black o-ring, white o-ring and plastic washer. The "kit" is almost $20 if I remember right as I've purchased a number of them to replace on the other spools. I had it in my mind that the black o-ring was the problem when it was the white one.

Kioti does not have a part number of this white o-ring. They are junk and turn jellyish after a few years.

I went through my assortment and found a nitrile o-ring that was very close in size by eye, I put in and she's working as she should now.

I'll get an o-ring sizer and figure out precisely what size the white one is. I is not totally round but seems flatter and round.

Here's some pictures.

The black o-rings are 17.1x1.6-70, they are $8 per from Kioti, I purchased 25 from ebay for 15 delivered.

The white I replaced with an 15.8 x 2.4, so far so good. Likely not perfect, but it solved my problem with 30 minutes of use and no problems.

Nimco valve body. If anyone happens to know the dimensions of the white o-ring I'd much appreciate.

Thanks,
Joel