Low Hydraulic power/pressure

[jbain]

Hi, I have a 2000 DK35 with 1300 hours on it with Kioti loader. Have no hydraulic power to speak of. The FEL and 3Pt move but neither have any lifting capability.

I can't lift the front of the tractor off the ground as I have always been able to do.

I can only lift the TW60 brush hog about 5 inches where before I could lift it up to the stops.

I have changed the filter with a Kioti filter and the fluid level is good.

This happened while mowing a field I noticed I could not raise the mower up.

I have checked all connections where the FEL comes off the hydraulic system and all are tight.

Has my hydroulic pump gone out?


Thanks,

 

[AWSubie]

It is possible that your hydraulic pump has failed but at 1300 hours it isn't as likely as perhaps a bypass getting stuck or maybe a packing failure. Go to the hydraulics forum and search for " low pressure" there is a tremendous amount of information there that will help you troubleshoot to determine exactly where the problem lies. Many of the troubleshooting procedures cost only a few dollars in simple tools (hydraulic port caps, inexpensive pressure gage and male/female couplings).

 

[SSdoxie]

If your hydraulics worked fine when you went out to mow and did not use them other than to lower the mower it's doubtful the relief valve is stuck open because that vavle has to be forced open when pressure reaches the max setting before anything can flow through it to get stuck.
Does your DK35 have rear remote (hydraulic couplers at rear of tractor)? If so look at the lever beside the seat marked A & B, make sure that lever is neutral not pulled into either A or B position. If it was/is locked in one position move it to neutral and try your loader or 3 point to see if power is back.
If the lever was locked in position and hydraulic power is not restored with lever in neutral that means it ran too long pumping oil through the relief valve and overheated the gear pump.

 

[mddorange]

:welcome:
To the forum Jbain. You came to the right place to get answers.

 

[jbain]

If your hydraulics worked fine when you went out to mow and did not use them other than to lower the mower it's doubtful the relief valve is stuck open because that vavle has to be forced open when pressure reaches the max setting before anything can flow through it to get stuck.
Does your DK35 have rear remote (hydraulic couplers at rear of tractor)? If so look at the lever beside the seat marked A & B, make sure that lever is neutral not pulled into either A or B position. If it was/is locked in one position move it to neutral and try your loader or 3 point to see if power is back.
If the lever was locked in position and hydraulic power is not restored with lever in neutral that means it ran too long pumping oil through the relief valve and overheated the gear pump.

Thanks for the reply. I'll check the remotes but don't think they are stuck as anytime I engage hydraulic I can normally hear the engine load a little. I did raise and lower the FEL to miss things such as fences while I was mowing. I just out of curiosity got a price on a new hydraulic pump $1167 so will be examining this problem very closely as to not have to purchase one. I ordered a pressure gauge and coupler so I can check the pressure.

 

[jbain]

:welcome:
To the forum Jbain. You came to the right place to get answers.

Thanks,

 

[jbain]

Ok, I checked the pressure on the hydraulic system and at the remotes it is 1000 PSIG at 2400 RPM. I pulled the pressure relief valve out and it seemed to be okay as it is a very heavy spring so don't think it could be bad.

This is leading to the hydraulic pump as the culprit.

Anyone got any other ideas?

 

[AWSubie]

Is your relief valve adjustable?

 

[jbain]

Is your relief valve adjustable?

I don't know do you think the tension on the spring would lesson over time to the extent that the pressure would be off 1400#?

 

[jbain]

I don't know do you think the tension on the spring would lesson over time to the extent that the pressure would be off 1400#?

In the service manual it says it has shims to adjust the spring tension.

 

[jbain]

Any one ever adjust the spring tension?

 

[AWSubie]

If the service manual tells you how thick a shim you need to increase the pressure x % then it (in my opinion) would be worth trying to increase the pressure a few hundred PSI just to see if the pump will do it.

 

[jbain]

If the service manual tells you how thick a shim you need to increase the pressure x % then it (in my opinion) would be worth trying to increase the pressure a few hundred PSI just to see if the pump will do it.

Wish the service manual was that detailed but it's not.

 

[Coyote machine]

Have you checked each and every quick connect at the underside of the right side floorboard where they all interconnect to allow FEL function? If NOT, then check them all and try pulling them apart by hand. It's possible to hit something sticking up in a field or wooded area and disconnect partially, and then so does function control.
Look elsewhere to make sure there are no hydraulic leaks you don't see, with cardboard or a piece of wood, NOT your hand. Don't look for the most detrimental problem, it's not likely. What exactly happened when you were mowing to create this situation. were you lifting the loader to get it above a fence section or what? Have you experienced any odd issues prior to loosing power? What do you most use your tractor for? Could you have deadheaded the pump- leaving a rear remote engaged with no flow?

 

[jbain]

Have you checked each and every quick connect at the underside of the right side floorboard where they all interconnect to allow FEL function? If NOT, then check them all and try pulling them apart by hand. It's possible to hit something sticking up in a field or wooded area and disconnect partially, and then so does function control.
Look elsewhere to make sure there are no hydraulic leaks you don't see, with cardboard or a piece of wood, NOT your hand. Don't look for the most detrimental problem, it's not likely. What exactly happened when you were mowing to create this situation. were you lifting the loader to get it above a fence section or what? Have you experienced any odd issues prior to loosing power? What do you most use your tractor for? Could you have deadheaded the pump- leaving a rear remote engaged with no flow?

This is an old 2000 DK35 so it does not have any quick connects below the deck for the FEL.

I was mowing and went to lift the FEL above a fence and could not. After I had changed the filter and fluid the FEL and 3PT would work but not under load. I think this was because the fluid was more viscus allowing the pump to make some pressure.

There were no leaks.

I have determined that the pump is bad based on both the FEL and 3PT have the same symptoms.

Both the FEL and 3PT have separate pressure bypass valves so it would take both of them out at the same time which is unlikely.

I'll follow up once I get the new pump in.

 

[jabelding]

Dk has a open center system like most tractors. Oil runs in a circuit from the pump - loader valve - rear remotes- 3pt lift. If there is a bypass in the system it will effect the pressure throughout the entire system down stream. IE if the loader relief is holding the pressure at 1000psi the entire system will be at 1000psi including the remotes and 3pt. Should only be one pressure relief on the loader valve for the entire system.