Using Loader hydraulics as rear remotes.

[OkieM8560]

Hello all, I'm new to the forum. Sorry about the novel, just trying to include all pertinent info.

I recently purchased an M8560. I planned to utilize the loader hydraulics to operate the boom fold on a 60' X fold sprayer I own. I built hoses with couplings on both ends to extend hoses for the boom fold on sprayer up to the loader hook up.

Here is the problem...the loader up down control can function the left or right boom without issue. However the bucket tilt function cannot operate either left or right. Both sides will retracts but seems to not vent oil when extending boom. High pressure is accumulating in the lines and it seems hydraulically locked in place... The only difference I can find between the loader and sprayer circuits is the hydraulic check valve on the sprayer cylinders designed to hold oil in cylinders to prevent the boom moving from leak down.

The booms work properly from rear remote and from loader up down pair...i have eliminated a hose as an issue by swapping them from functioning perfectly on loader up/down, to non-functioning on the tilt function. Loader up/down is a float valve and tilt is not. Although I don't think that matters.

Needless to say I'm stumped and I'm hoping someone can enlighten me.

Thanks

 

[eserv]

Kubota use what they call "regen" on the bucket tilt on your model and many others. This means they direct oil to the rod end of the cylinder to retract the cylinders and direct oil to both ends of the cylinder to extend them. This causes the cylinders to extend and retract approximately at the same speed whereas if they done it conventionally the dump would be much slower than the tilt back. This works good on their loaders but as you found out isn't very good for other applications! Depending on the dimensions of your cylinders this might still work in your application if you ensure that the hoses are connected to the cylinder the same way they are on the loader.

 

[OkieM8560]

Eserv, thank you! I spent hours swapping lines all around, I believe I attempted swapping the pair but maybe not. Either way this nugget of info will greatly help me figure out how to solve the issue. I'll research if the regen circuit will work with a cylinder check valve.

 

[eserv]

Eserv, thank you! I spent hours swapping lines all around, I believe I attempted swapping the pair but maybe not. Either way this nugget of info will greatly help me figure out how to solve the issue. I'll research if the regen circuit will work with a cylinder check valve.

For the cylinder to extend the oil must flow from the rod end back to the base end of the cylinder. If the cylinder check valves prevent this it won't work!

 

[eserv]

For the cylinder to extend the oil must flow from the rod end back to the base end of the cylinder. If the cylinder check valves prevent this it won't work!

When the cylinders extend the oil from the rod end gets added to the oil coming from the tractor hydraulics going into the base end to make the cylinder go faster.

 

[OkieM8560]

The sprayer has a double piloted hydraulic check valve. Which requires pressure to go up either hose to open the vent hose check valve and allow it to vent. A regenerative circuit pressurizes both lines and therefore should open both check valves and allow flow to "regen" as normal...but like you mentioned if the cap and rod lines are reversed the system will hydraulically lock because cap returns are greater than rod returns. I don't specifically remember swapping each line. So there is hope that will fix it. If not I might have to remove the check valve for this season until I add another rear remote. Thanks for your help!

 

[OkieM8560]

I believe from taking the check valve apart last week that it has a shuttle valve that opens the non pressurized line check valve and allows it to vent. The problem is the shuttle cannot move in a regenerative circuit because both lines from the tractor get equal pressure...so the shuttle remains in the locked position! Atleast with your help we figured out whats going on. Unfortunately it seems the check valve will need bypassed this season.