2015 E20 bobcat

[R.T.E.]

swing function for both left and right-side turn is choppy until any other function is slightly applied then the machines turn smooth, left side jot stick controller has been changed out with a new one. Any help is appreciated, thanks R.T.E.

 

[walio123]

if the hoses on the joystick are connected correctly, and the forward - backward movement of the joystick works correctly - it sounds strange. When you slightly give some other movement, the pressure in the pilot line rises, which means that somewhere there is a leak of pilot pressure. Check the slew section of the hydraulic main valve.
Any chance of swapped joystick hoses - specifically the P and T ports?

 

[R.T.E.]

thanks for your reply, I will check or swap out the p and t port hoses and check if any change, just got this machine and that's how i received it with this issue so not sure what was done ,its like they tried to repair the problem but couldn't, i did find a light spring on the foot floor about an 1in dia and 2" long no idea where it goes. the floor panels were off and the left joystick covering was loose.

 

[walio123]

thanks for your reply, I will check or swap out the p and t port hoses and check if any change, just got this machine and that's how i received it with this issue so not sure what was done ,its like they tried to repair the problem but couldn't, i did find a light spring on the foot floor about an 1in dia and 2" long no idea where it goes. the floor panels were off and the left joystick covering was loose.

Those spring may be from slew section,remove the caps where slew pilot hoses goes and that can be a point to go. Have a look at attached picture. N12 are centering springs....if one is missing it is possible to act like you described.

 

[R.T.E.]

thanks, I agree i will check this out tomorrow and hopefully can find something

 

[R.T.E.]

everything looks good those springs are no where close to being the same size as the ones on the relief valves, i will have to start checking pressures

 

[walio123]

I think it's the centering spring under the valve section cap. It's about that size. The springs of the safety valves are much smaller. Those springs are number 12, caps are number 10 and relief valve is 5.

 

[R.T.E.]

checked for springs and its all good, checked my pressure at main relief port , was a little off but not by much, adjusted to specs, then checked my cross port relief and its dead on,

 

[walio123]

cross port relief

Тhere should be 2 cross port relief valves also known as brake valves.Here's an example of how they work. . Yes they can cause such symptoms, but I don't see how activating another movement can affect them. Maybe a problem with the joystick...swap the swing hoses with the joystick dipper hoses and see if that makes a difference.

 

[R.T.E.]

It's a brand new joy stick assembly

 

[walio123]

Then the problem remains in the valve section or the hydro motor itself...rather it is in the valve section....does that spring you found look like the springs under the pilot pressure cap in the section ?

 

[R.T.E.]

No it dose not look like those they are a little bit heavier and besides it looks like the valve has about 8 years worth of dirt and debis on and around it I had to dig and clean just to get to the pressure caps

 

[walio123]

Can you measure pilot pressure? What is readings when swing is activated and when other function is activated ? Is there a pulsating pressure? Could the slew motor have been dismantled - any marks on its bolts, on the hoses? There are brake springs inside it..I think they are smaller than the one you found....what you describe is quite strange. Although the joystick looks like new, I would still swap the hoses there....

 

[R.T.E.]

I changed out the joy stick thinking that was the problem , the pilot pressure has not been checked trying to figure out the instructions on how to do that the slew motor
Seems to be intact it was dirt and crud on it as well we pressure washed it the brake seems to be holding when I do the cross port test I had to discontinue the brake line hose and plug it so the machine wouldn't turn when I activated the swing function the cross port test was hard to notice but was a slight movement on the gauge but not like 100 psi just barely moving off it's mark and it is within specs

 

[walio123]

there must be a point for measuring the block with the hydraulic accumulator - pilot pressure is measured there

 

[johnloaderowner]

It sounds like you've been thorough in checking the joystick and associated components. Since the issue persists even with a new joystick, it's likely related to the valve section or pilot pressure. The problem you're describing often points to pilot pressure issues or a problem within the valve itself.