I have a 2002 KX41-2V that has been working perfectly except for blowing the 15 Amp engine shut off fuse. It reached 1,000 hours so I changed the hydraulic fluid and the two filters. After restarting the machine the joy sticks are not functioning, no boom, no arm, no bucket no machine swing. Tracks work, blade works, boom swing with foot control okay. I have tried bypassing the safety lock outs to see if a faulty switch is the problem and that changes nothing. As I said everything was fine until I changed the hydraulic fluid and filters. I have checked the other fuses and they are okay. The wiring diagram shows the lever lock switches on the same fuse as the fuel pump so since the machine runs that fuse is definitely okay. Purchased a WSM for the machine and the troubleshooting schematic doesn't mention this problem. I'm stuck. Thanks for any help.
Sounds like the servo/pilot controls have been 'cut off' as to why - I can't think what changing the oil and filters would do to affect this!! Severe air lock in the hydraulic pilot circuit maybe. When you drop down the armrest(s) to you feel/hear the flow come in for the joysticks?
Interesting that everything low works and everything high won't. I think Strott is onto something about the airlock. HTH Jay.
Definately air locked if you didn't have a prob earlier., did you fill the hyd filter prior to spinning it on?, Try moving the track, and boom control and hold till you hear a whine. Then reverse position. Only do piston at a time, meaning, purge lift before the dipper. When you have a good response from one function, do the next. Save the swing for last as it isn't a large oil mover. Check your sight glass on your tank. If it is frothy, the system is either purging out the air, or a hyd leak on the suction side has developed. I believe that machine uses super UDT. Did you use Kubota Hyd Fluid? Let me know.
There is no feeling of flow coming into the joysticks when the safety levers are engaged. An airlock being the culprit seems right and the troubleshooting section of the WSM that I finally received does talk about checking the pilot valve when there is no actuator action. However, not being at all familiar with hydraulic systems reading about "check the pilot valve" and actually doing it is a big stretch. Is this a complicated procedure? Really appreciate the help. My Kubota dealer has no clue with this machine.
I think everything 'low' on the kubota mini's are driven direct from the valve block e.g levers connected direct to the valves so that is why they work. Which at least proves that the pump still works!! - are these functions which currently operate working at the speed they usually do??
Thanks for the response equip guy. To answer your questions, no I didn't fill either of the 2 hydro filters before installing them and the fluid I used was not Kubota but it does meet Kubota's specs. I'm going to jack up the machine and run the tracks as you suggested and I'll let you know what happens. Thanks for the help.
Thanks Strott. You are absolutely correct, the functions that are still working, (and at normal speed) have mechanical linkages to the valve block. BTW my parents used to live in Swindon in the last century.
I had a very similar problem happen to my KX 41 - 3. When I pulled out the floor board I found a wire had been chewed through by a mouse. I simply spliced the wire and it was as good as new. I hate mice.
Kinda on a limb here, but I have to get past this first. Fact, you had been blowing the 15A fuse for "engine shut off". So it's now not blowing the fuse? You said the lever lock switches (which is the joystick pilot valve circuit) is on same circuit as fuel pump, meaning "engine shut off"?
Lots of mice here in the mountains so that might be a possibility. I've checked every wire that I can see under the floorboards but might have missed one. Can you describe where the wire was that you found chewed? I'll second the hate for the mice comment.
The blowing of the 15A fuse occurred prior to this problem and I think accounts for the ignition key not shutting off the engine since this circuit has the engine stop timer relay on it. There is a mechanical linkage provided to close the fuel flow as an alternate which I have been using. There is obviously a problem with this circuit that I have to track down, but I don't think it is related to this problem. However, I could be wrong....it wouldn't be the first time.
Still no joy Tried your suggestion, jacked up the machine and had the tracks moving and then tried one movement of a joystick for an extended period. Still no action and there was no whine produced. Also no forthiness in the sight glass. However, it was helpful in that I now know the accelerator pedal which activates a switch similar to the safety lever switches is not working. Going to do some electrical circuit testing tomorrow to see if I can figure out why that 15 amp fuse is blowing and if there is power getting to the lever lock solenoid and the acceleration solenoid. Thanks again.
Sort out the electric problems if you can - before playing with hydraulics. The pilot circuit is probably electronically actuated so it would be a coincidence if two unrelated things went wrong at once, but you never know!!
You have too many things going on at once gcsthomas, these sort of things tend to make ones head spin. It could be nothing more than pure coincidence that you lost upper hydraulic functions when you changed hyd oil and filters, I've seen stranger things happen. :yup But in your case, I would for now ignore the big picture of this not working, this problem, that issue...keep it simple. The thing I would first focus on is the upper not working. If your safety lockout system is controlled by a switch, or switches, in the operator compartment, it's a safe bet the pilot control circuit is controlled by an electrical solenoid valve. The first thing I would do would be locate that solenoid valve. Disconnect the wiring harness from the solenoid coil. If the solenoid has two wires, one would be a ground, make a ground for solenoid with jumper lead. Then connect a positive voltage jumper lead to the solenoid power wire, you should get a small electrical arc when you connect that jumper, and should hear a faint "click" of the solenoid. If it does these two things, see if the upper machine now operates. If you get a big electrical arc when connecting positive jumper lead, solenoid coil shorted out. If you get no electrical arc and hear no click, solenoid coil most likely fried.
It's hard to say as this was 3 years ago but it was clearly visible. Sorry I can't be more helpful. Also had mice shew a wire in the engine compartment but not all the way through. Also they filled my air cleaner wiht seed. How they get in there I have no idea. I hate mice.
Hi gcsthomas, I have the exact same problem with my KX41-2. Could you share what you found out to be the issue with the pilot control system?
I also have the exact same problem on my KX41-2, I know this is an old thread but figured I’d throw up a prayer!
Gm, anyone have their fix for this? I just had this happen to my machine yesterday. Exact same conditions except worked 2 weeks ago now pilot controls don't actuate. Didn't change anything. Where is the cut off solenoid for pilot controls? My safety switch in armrest is working, no blown fuses, bottom functions are all working as normal. Tried cracking some pilot lines on the spool valve, nothing, it's like the solenoid valve is closed not allowing pressure to pilot valves... Any new ideas?
It was the solenoid valve under the fuel tank, you can gain access from under the machine. The solenoid closest to relief valve controls the pilot functions. Give it a tap to see if it will unstick itself...