Auxiliary Hydraulics Headache!

[parksplace5454]

Hi,
I purchased a near-new Gearmore box grader with hydraulic ripper and a separate 3-valve auxiliary assembly to use on my Kubota L35. I have attached the tractor hydraulic pressure and return lines to the auxiliary valve assembly and the two lines from the Gearmore ripper piston to the two fittings on one of the valves of the 3-valve assembly. When I operate the auxiliary valve, I can hear the hydraulic pump on the Kubota straining but the Gearmore piston does not move. I removed the two lines going to the Gearmore piston and operated the auxiliary valve; hydraulic oil shoots out of each of the valve ports as I operate the handle in each direction. I have surmised that the piston is being pressurized on one side when the valve is being operated but the fluid is not being allowed to release from the other side of the piston through the valve assembly. What am I doing wrong?
Thanks
ParksPlace5454 (covered in hydraulic oil!)

[MichiganIron]

Originally Posted by parksplace5454

Hi,
I purchased a near-new Gearmore box grader with hydraulic ripper and a separate 3-valve auxiliary assembly to use on my Kubota L35. I have attached the tractor hydraulic pressure and return lines to the auxiliary valve assembly and the two lines from the Gearmore ripper piston to the two fittings on one of the valves of the 3-valve assembly. When I operate the auxiliary valve, I can hear the hydraulic pump on the Kubota straining but the Gearmore piston does not move. I removed the two lines going to the Gearmore piston and operated the auxiliary valve; hydraulic oil shoots out of each of the valve ports as I operate the handle in each direction. I have surmised that the piston is being pressurized on one side when the valve is being operated but the fluid is not being allowed to release from the other side of the piston through the valve assembly. What am I doing wrong?
Thanks
ParksPlace5454 (covered in hydraulic oil!)

Sounds like you may not have picked the proper 2 work ports on the control valve. Work port positioning on the valve body may not be what you would guess.

Are you working from a diagram to pick the work ports, or did you pick 2 ports near a spool?

[parksplace5454]

Thanks for the comeback,
I do not have a diagram for the valve so I am connecting the hoses to work ports near a spool. The valve is a Dinoil and has "DO1E801" cast into the bottom of the valve body; I haven't been able to locate any other identification.

[kennyd]

Where did you get the valve?

Did you try another spool on the valve?

When you took the hoses off and operated the lever, did fluid come out BOTH of the ports? If so...I can answer your question.


I looked for info on your valve but came up empty...

[3RRL]

Looks to me you have it correct.
The other work ports are plugged off, right? You might start checking the Gearmore to see if it has a locking feature which locks the rippers in place. Or at least if there is no other mechanical obstructions to prevent the hydraulic rippers from functioning.

[parksplace5454]

I purchased the box grader and aux valve assembly from a small dealer in Flagstaff, AZ; they had both been removed from other tractors. I was told the valve assembly had been on another Kubota tractor.

When I remove the hoses from the work ports and operate the valve, fluid comes out of one port when the lever is operated in one direction and out of the other port when the lever is operated in the other direction.

I didn't notice any sort of lock on the rippers but I didn't really look for that; will check closer.

[Farmerford]

I think you are using the power beyond port as a return line to the tank, and have the return/outlet/exhaust line blocked by a plug. With the power beyond plug installed, the return fluid can only escape the valve through the outlet ports, and if the outlet is blocked, the return oil can't leave the cylinder.

[parksplace5454]

I tried something new today... starting with the grader cylinder connected to the two workports, I removed one cylinder hose from the valve, put it in a bucket, and then operated the valve. The grader cylinder operated to the end stop. I then reconnected the hose to the valve, removed the other work port hose, and repeated the process in the other direction. The grader cylinder operated in the opposite direction to the end stop. When I connected both hoses to the valve, I am back to nothing moving and the tractor hydraulic pump straining.
When I hook up my backhoe with it's own valve assembly to the tractor hydraulics, everything oerates normally.
It appears as though I have some sort of issue with the Dinoil valve assembly???

[Willl]

Almost sounds like you got your return line piped into your Power Beyond port.

[Farmerford]

I think the issue is that the valve has a power beyond plug installed, which means that it must be hooked up with three hoses: (1) the inlet (pressure) hose that brings high pressure fluid to the valve, either directly from the pump or (more likely) from the power beyond port of an upstream valve. (2) the outlet (exhaust/return/tank) hose that takes fluid returning from the cylinder to the tank. (3) the power beyond hose that takes the high pressure fluid that is not directed to the cylinder through the work ports to the next valve (probably the TPH).

In the photo it appears you only have two hoses, and that is what your narrative suggests. If that is true, and since the valve came from another tractor, where it was probably configured for power beyond by installing a PB plug in the "PB" port, then your exhaust flow from the cylinder has no way to get to the tank through the valve. That's what I tried to explain (perhaps to briefly) in my previous post.

Try taking the plug out of the valve "out" port. I'll bet that the cylinder works, but fluid squirts out of the "out" port when it does. The fix is to run a third hose from the out port to tank, and it can be teed into any other return hose.