Kubota KX-41 Hydraulic Problem

[Invisible-Man]

Hi Everyone,

I have a Kubota KX-41 about year 96, the controls are actually hydraulic and not the older cable.....

Anyways, the problem is with the main boom (right hand control forward and back)

After lowering the boom, sometimes when raising again it struggles to lift, and at that time if bucket is loaded the boom is actually dropping very slowly, if I move lever forward and back a few times rapidly, it will correct itself, sometimes with a valve type noise sealing itself.........it seems to me that a valve is not closing fully after using the lowering service and obviously when trying to raise, struggles due to a valve not closed fully from the lowering service.....

Any help would be greatly appreciated to pinpoint the problem.......

I assume possibilities could be sticking pilot under the control, or the relevant spool valve needing cleaning or replacing......

Many many thanks

[Muz]

Could be several things

If you lift the boot off the control handset, can you observe the pilots working normally (popping up and down) whist the problem exists ?

They can get stuck down... also some other service may be jammed like a breaker and stealing oil

or there may be a seal pack problem in the ram

pilots first what do you see ?

Welcome BTW

[Invisible-Man]

Could be several things

If you lift the boot off the control handset, can you observe the pilots working normally (popping up and down) whist the problem exists ?

They can get stuck down... also some other service may be jammed like a breaker and stealing oil

or there may be a seal pack problem in the ram

pilots first what do you see ?

Welcome BTW

Thanks Muz,

To be honest I have looked at the pilots closely for them sticking, but only when machine not running........pretty strange really as it seams to be very rare for it to happen on some days, when other days almost all the time.........I will try and do what you suggest and try and catch it happening whilst monitoring the pilot buttons.......

Does it sound like an inexpensive problem in general? I am ok at changing parts myself.

Thanks again for your help

[Muz]

Thanks Muz,

To be honest I have looked at the pilots closely for them sticking, but only when machine not running........pretty strange really as it seams to be very rare for it to happen on some days, when other days almost all the time.........I will try and do what you suggest and try and catch it happening whilst monitoring the pilot buttons.......

Does it sound like an inexpensive problem in general? I am ok at changing parts myself.

Thanks again for your help

Probably more time consuming than anything else .. but its hard to say at the moment .. your in the right place to find how to do it most economically thats for sure ..

Remember that the pilots do have a little pressure to them, so they will act differently with the engine off.

[Invisible-Man]

Probably more time consuming than anything else .. but its hard to say at the moment .. your in the right place to find how to do it most economically thats for sure ..

Remember that the pilots do have a little pressure to them, so they will act differently with the engine off.

Well used digger again recently, problem still exists on occasions, definitely not sticking at the control........

I believe when considering my first explanation, that it is a control or relief valve of some description sticking open sometimes, can anyone tell me what control or relief valves are on the boom lowering circuit and whether they operate as a matter of course or just when excess pressure build up..........I thought you needed a valve to operate when the boom is lowered to its lowest position in order to relieve pressure?


Any help appreciated!

[Muz]

Well used digger again recently, problem still exists on occasions, definitely not sticking at the control........

Just to be clear .. the control sticking is not what I'm getting at .. its the four pistons underneath the circular plate not popping up that I'm referring to .. they have a habit of sticking, and is the most likely cause of your problem .. you need to be certain they are ok before you proceed