Help. Tractor hydraulics weak

Hello. Hopefully there are hydraulic guru’s here that can help.

My compact Kioti CK20HST suddenly lost power and speed in the loader and 3-point. Hydro drive and steering seem ok but it’s hard to say.
Engine runs normal.

I drained hydraulic fluid and changed the 2 filters (hydro drive has it’s own)
Fluid looked dark.

Hydraulics are better but far from normal.

I rigged up a pressure test gauge to the rear remote and psi definitely seems very low! 1500psi max?
Also seems to spike then slowly drops. I feel like that could suggest something?

Please give ideas? Is the pump shot? ($800!!!) Pressure relief valves stuck open? Other?
:eek:


View attachment 450912
Another filter or screen perhaps on suction tube?

Chuck
(Sorry I missed the other posts)
 
Ok. A quick follow up. (Very busy currently)
Gear driven pump. Driven off the back of the fuel injector pump on the side of the engine.
23562708-6ECC-4287-B7C3-2E681446764C.jpeg
Pressure relief valve is on the distribution ’manifold?’ off the rear of the pump.

Fluid is pulled throughout a main filter before the pump. (After the filter, there is a 2nd filter on a branch for the HST with it’s own crankshaft driven pump)

From the dealer, working pressure should be just under 3000psi. Pressure relief should be around 3600psi? (I wrote it down at work and forgot to bring it home…) I need to double check those stats because the kid was helpful and nice… but new.

The mechanic in the shop felt that there is a 95% chance that the pump is toast. (Although they don’t see many problems with the pumps *sigh*)

I need to look everything over good. I’m not loosing fluid and have not seen any massive leaking. I’ll probably pull the pump and check for wear.

I checked with another good hydraulic shop I’ve used before and they said they can’t rebuild this gear driven pump… new is $800 :eek:

I also need to cut the filters open to see what’s in there
 
If you can get to the pump outlet, remove all the valves on the back, run a hydraulic line from the pump to a T. One side of the T has your pressure gauge, the other runs to a valve and back into a transmission fill cap. Open valve all the way, start tractor and slowly close valve, the pressure should get to the spec (do not go past that). There should be a strong flow, whatever the spec is at that engine rpm.
If the pump is not up to spec there is still a chance there is an issue on the suction side (clogged strainer or air leak).
Or bring the pump to the shop to have them test it.
I agree with tim young, it is more common for pumps to slowly wear out than go bad all at once
 
Put 2 pennies behind the relief valve spring, Just my 2 cents! Just kidding don't do that! :D

With the dark fluid, Sounds like something got hot and burned the fluid. Cutting the filters open like said by another poster sounds like a good plan to start.
 
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