CK 20 Hydro Won't Go No Mo

[skipples]

Encountered a hydraulic problem when a branch caught the fluid return pipe (the short one from the engine area heading back) and bent it causing a loss of fluid on my 2003 with just under 200 hrs. that I've had since new. Got it back into position and jury-rigged new hoses because the old ones were too short. Ordered a new pipe, hoses, etc. but continued to use the tractor with no problem after adding a couple quarts of hydro oil to replace the lost fluid. After a couple of weeks of hard use with a tiller, out of the blue she would only move with loud noise and a shuddering, halting motion in both directions. The loader and 3 pt worked fine, however. I let it sit for a day or so and was able to drive -albeit slowly with intermittent shuddering- up to the garage where I did a full hydraulic oil change w/filters and the new return pipe. I then found that the bent pipe was cracked. The oil/fluid was a bit dark, foamy at the tail end, and the remains of some type of small 'keeper ring' stuck to the magnet. (At the 50 hr service there was a bit of metal debris stuck to the magnet and all has been well since then so I wasn't overly concerned.) After the oil change, the 3 pt and loader work only slowly with considerable shuddering and the tractor won't budge in forward or reverse. I have to place it in neutral to roll it because the tranny seems to be engaged so I don't think the shaft is broken. Anyone have a similar experience with this model? (I'd take it to a dealer but I live in southern California and they're hours away. I don't know if the local tractor shop can be trusted so I'd like a more definite diagnosis to help ID my options.)

 

[IslandTractor]

Sorry to hear of your no go situation. As everything worked before the damage to the return line it seems obvious the problem is related to that event. Your 50hr experience with finding fine metal filings on the HST drain magnet is normal but finding a piece of a "keeper ring" now is certainly not. Were you steadily losing fluid before you discovered the crack in the return line? I wonder if the noises you were hearing was cavitation in the HST pump due to low fluid levels. Did you check the level when it started malfunctioning again before you changed the hydraulic oil? Did you change both filters when you changed the hydraulic oil?

The foamy appearance of the HST oil is something I noticed once on my CK20 after I had inadvertently overfilled with oil but I don't know how that might be related to your issue. In my workshop manual for the DK series it notes that bubbles in the fluid indicate a problem with the inlet line of the gear pump which is exactly what you described.

Can you check the pressure in the hydraulic system? I suspect that will be an important diagnostic step. In the DK40 manual they break down the issues for poor or no drive power based on low/high or normal hydraulic pressure.

I don't know that would be the same for the CK20 but in case it is useful here is what needs checking on the DK40 with similar symptoms:

Low charge pressure: clogged filter, damaged relief valve, hydraulic line related to 2nd gear pump is defective.

Low pressure in high pressure relief valve: relief valve defective, HST plate worn, HST cylinder block and piston worn.

Normal pressure of high pressure relief valve: O ring of servo piston is warn.

Please understand that these come from the DK40se workshop manual and may not be relevant to the CK20 (although the general ideas seem on target to me). Maybe one of the dealers will pop up and offer some advice.

Good luck. I hope it turns out to be something simple.

 

[JohnnyO]

Thanks for the info, Island/Ed,

Before replacing it, the return line had a drip I thought was related to hose/clamp issues and the small break was on the back side out of sight. I just retightened everything because it was leaking again and now have good fel and 3 pt operation but still no go on the hydro. Replaced all filters and drained/replaced all fluid. I have no way (neither knowledge nor tools) to check hydraulic pressure . Clutch now makes some small clank noise when released after depressing but it still will not roll without being in neutral so it seems that nothing in the drivetrain connections went away. Maybe somehow the hydr got an air bubble in it so fluid isn't flowing correctly. I have the shop manual but the troubleshooting steps are pretty technical, other than oil level, linkage and the basic filter change, etc. I could probably replace the clutch or other mechanical parts but not the hydraulic system. I just need to rule out some things in order to determine a course of action.

 

[skipples]

BTW: Skipples is JohnnyO but I couldn't find my user name so I had to re-register. Later found it on my other computer......

 

[wallace]

Did you replace your hydraulic fluid and if so what did you put in it?
Did you use a transmission fluid or a hydraulic/transmission fluid?

 

[skipples]

Put in "Super Tech heavy duty tractor hydraulic and transmission oil". Says it meets the Kioti published specs also Kubota UDT specs and is for use with single oil type systems for trans, hydraulics, brakes, PTO, etc.

 

[IslandTractor]

I have no way (neither knowledge nor tools) to check hydraulic pressure

I believe that a pressure gauge is not very expensive and other than that all you need is some hydraulic hose and fittings available at any local hydraulic shop. Check out surplus supply dot com or ask Rick Wallace for advice on how and where to measure pressures. As you are far away from a Kioti dealer you might want to scout out another tractor dealer as these HST systems all work on the same principles.

 

[kennyd]

Here is my thoughts...

You wrote:

I then found that the bent pipe was cracked. The oil/fluid was a bit dark, foamy at the tail end

The return pipe was cracked, so the system was sucking air-evident by the foamy fluid, and the two main pumps where cavitating through the "hard use with the tiller". I suspect your hydrostatic pump for the transmission and the main hydraulic pump are toasted.

 

[skipples]

Yeah, Jon DePratt (who I get parts from) emailed a simple test of the charge pump and it wasn't good. I'm off to talk to the local tractor shop about their knowledge of these little beasties. Better take my checkbook...........the Bakersfield, CA Kioti dealer told me they get $80 per hour. I don't know what parts cost or how many labor hours are involved, though.

 

[Highbeam]

I guess sucking air into these things is bad then? I've broken off a couple of the filter mounts for the low hanging grey hydro filter and when you replace them the connections are a simple O-ring kinda pushed in place with no positive threading. So it looks pretty easy to accidentally create an air leak on the suck side of the pump.

Moral of the story... check the fluid for level and for foaminess.

I will be curious on the quotes you get just to see how expensive these transmissions are.