Detent Rear Remote Damage/Pressure Readings/Pressure Relief

toukow · Mar 22, 2020

Per the title, I am hoping you guys can educate me on a few things as far as hydraulics on my new CK2610 HST tractor (30 hours). I wanted to make sure the backhoe was operating a full pressure, hence the gauge installation. I have several questions:

1. I am glad I read in the thread 'Three Point Not Lowering' about not leaving the detent rear remote in the engaged position when not using the attached implement. I reread the manual
and this apparently can raise the temperature of the fluid and damage components. I infer for the damage to occur, the ENTIRE fluid supply (6 gallons) must raise up in temperature,
not just some particular hydraulic line/smaller reservoir of fluid. Is this correct? I ask because the manual does not state an amount of time for this damage to occur, and I am curious
if it happens in 15 minutes or 5 hours, with the latter seeming more reasonable.

2. The manual for the backhoe states the pressure relief valve is adjusted by 'Removing the acorn nut and using a screwdriver' which is how my last tractor was setup. I do not see such a
device, so am asking if the device sticking down under the 'end block' is the pressure relief adjustment? If it is, does this look like a shim style or screw adjustable type?

3. I hooked up a pressure gauge as shown in the schematic, but am confused by the results. Detent valve off, I have zero pressure. Detent valve engaged, but no implement operation- I
have 300 PSI. Operate backhoe to initiate pressure relief and I have 2000 PSI.

a. I am confused by the 300 PSI reading, as I thought a deadhead condition was being created with the valve engaged, but no operation of the attached implement- thus the rise in fluid
temperature. Does this number look right? What am I missing?

b. The 2000 PSI value exceeds the manual spec of 1850 PSI, but I intend to leave it alone unless others disagree. Do you see any issues with leaving it at 2000 PSI (8% high)?

Thanks for the education. I still have the gauge installed if additional tests are needed. I hope you and your families are doing well in such trying times, Toukow

ericm979 · Mar 22, 2020

Do you have the detent valve feeding the backhoe? If there is something connected to the detent valve's out and in ports then the detent valve can't deadhead. The thing that's connected to it could though. Or you can bottom out a cylinder like the directions state.

The 300 psi you're seeing with all the BH valves in neutral would be from the resistance of pumping through the BH's valve stack and the associated hoses. Seems high but I've not seen a number for that before.

When I trip the relief on my loader valve I can hear it. It's not super loud and I have missed it in the past when I was concentrating hard on something else, but if I'm paying attention it's noticeable.

toukow · Mar 23, 2020

ericm979 said:
Do you have the detent valve feeding the backhoe? If there is something connected to the detent valve's out and in ports then the detent valve can't deadhead. The thing that's connected to it could though. Or you can bottom out a cylinder like the directions state.

The 300 psi you're seeing with all the BH valves in neutral would be from the resistance of pumping through the BH's valve stack and the associated hoses. Seems high but I've not seen a number for that before.

When I trip the relief on my loader valve I can hear it. It's not super loud and I have missed it in the past when I was concentrating hard on something else, but if I'm paying attention it's noticeable.

Yes, the detent valve is feeding the backhoe. So the warning in the manual of rising hydraulic fluid temperature is simply for pumping fluid through the stack valve at 300 psi I will assume. I do have very long 3/8" hoses making the connections to ease connecting the backhoe to the tractor, so perhaps that is leading to the pressure noted in neutral. Like I said previously, I'm unclear how long you have to leave the detent engaged without using the backhoe before damage may occur in the system, but won't worry too much about it and try to remember to disengage the detent.

Thanks, Toukow

ericm979 · Mar 23, 2020

toukow said:
Yes, the detent valve is feeding the backhoe. So the warning in the manual of rising hydraulic fluid temperature is simply for pumping fluid through the stack valve at 300 psi I will assume. I do have very long 3/8" hoses making the connections to ease connecting the backhoe to the tractor, so perhaps that is leading to the pressure noted in neutral. Like I said previously, I'm unclear how long you have to leave the detent engaged without using the backhoe before damage may occur in the system, but won't worry too much about it and try to remember to disengage the detent.

Thanks, Toukow

The warning is not for leaving is in detent while the BH is connected. It's leaving it in detent while nothing is connected- that's "dead heading", when the relief valve has to open.
When that happens the hydraulic system is pretty much non functional- you won't be able to lift the loader or the 3pt. You'd notice after a while, depending on what you're doing.

toukow · Mar 23, 2020

ericm979 said:
The warning is not for leaving is in detent while the BH is connected. It's leaving it in detent while nothing is connected- that's "dead heading", when the relief valve has to open.
When that happens the hydraulic system is pretty much non functional- you won't be able to lift the loader or the 3pt. You'd notice after a while, depending on what you're doing.

What you are saying would make total sense, but that is not the wording of the warning provided by Kioti. This is from my owner's manual on this issue, italics are mine:

'Put the detent valve operating level into the neutral position when the hydraulic implement is not in use. If the detent valve is kept in the operating positions for an extended period of time, the relief valve is kept open and the temperature of the hydraulic fluid rises, leading to damage of various hydraulic parts, such as the oil seals and O-rings. '

If this is just a poor English translation by Kioti then great, but the wording is specific, and hence my question. Sounds like it should say 'implement is not connected', instead of 'implement is not in use'. I'll assume you're comments are correct, and not worry about it. Thanks for responding, Toukow