Hi, I have a TB 145 and I’m having problems with the hydraulics. All functions work except for the stick/stick cylinder. I have tried adjusting the flow and replaced the seals in the cylinder, but nothing helps. It works normally until the last meter, where it becomes sluggish and stops. After a few seconds, it jumps forward. What could it be? Ive not been so worried about this but now its starting to be more and more Grateful for any tips.
Here is a video of the machine, Now its running full rpm
Is the rod bent on the cylinder, or any imperfections in the barrel?
No, i thought it was something to do with this, but now i changed cylinder to a new one but still same problem
No one else have any advice?
Does it have a case drain filter or a pilot filter?
No it doesnt
When’s the last time the filter were changed/cleaned? Acting like a proportional valve is sticking.
changed filter maybe 1month ago when it started to happen
Can you measure the pressure at the cylinder? Might be port relief valve failing or in need of adjustment.
I have tried adjust the port relief, and i have also switched some hoses to other functions and still same problem
Has this problem always been present or have you recently noticed it?
Recebtly noticed it, i think there is some problem in the maine valve
I would still try to measure pressure at the cylinder. Adjusting the port relief gave no results because it may be broken. I believe you can try to swap the port reliefs from some other function that works well and compare results. But I have never done this. If you would do this you probably have to know what are pressure settings on them. You would probably need a service manual for that.
Cylinder movement is slow and erratic. Without external force, the piston moves slowly and irregularly, like a creeping motion. This phenomenon is called "cylinder creep." There are three possible causes, which should be investigated one by one. 1. Air bubbles in the hydraulic oil cause unstable compression and release after pressure, leading to slow or erratic cylinder movement. Secondly, water may have entered the hydraulic oil, affecting its lubricity and fluidity, potentially causing clogged or sticky movements. Focus on the hydraulic oil first. Finally, a broken directional valve pressure spring can also cause this phenomenon.
I have made pressure and changed port reliefs but still same on the stick even if i swap, little confusee of next step
Thank you for your reply, i have changed the hydraulic oil total maybe 2weeks ago, Gonna see if i can find out how to do with thid directional valve pressure spring Thanks for your advice
Then I would try checking the poppets and seats in the control valve, like you said yes…
If the "slow then jump" is when the arm (stick) goes over center (hangs vertical), then there is a problem with the load sense to the pump. I'll have to dig for the theory.
Can you explain this about the load sense?
When function is activated, via a pilot hose, the main spool for that function shifts to allow oil to that cylinder (or other hyd implement). That oil going out to the cylinder creates a "load" for the pump to shift displacement. When the pump shifts internally, the pressure rises to that circuit. When the arm (stick) swings past free hang (vertical) there is no load and the pump destrokes. Once the momentum is gone, a load exists that strokes the pump back up. That's as simple as I can make it sound. There is a component in there to keep the pump stroked when the cylinder has no load. That's what is suspect. Perhaps someone else here can point you to what to chase.
These may be helpful, its from the workshop manual.