2007 JLG Boom Lift Platform only rotates one direction

[Travs Thompson]

I have a 2007 JLG Boom Lift. The platform does not rotate or rotates very slow to the right(intermittent changes when machine is shut off) and but work fine in the reverse direction.
The boom lines were recently replaced. (The lines run continuouse from the main control valve to the rotate actuator motor assmebly. No internal check valves). The control valve coils for the platform rotate were replaced. The platform rotate actuator was replaced. The platform rotate check valve cartridge was replaced.
After the platform rotate actuator motor assembly was replaced and that did not fix the problem I spend a good deal of time troubleshooting this problem.
When I reverse the lines to the platform rotate actuator, then platform will not turn the opposite direction.
When I swap the platform rotate lines with the platform level lines the platform rotates in both directions but the platform level function will not work in one direction. This also will reverse when I swap these lines. Plumbed one way it will not tilt up the other way it will not tilt down.
No change when I swapped the platform rotate control valve assembly with the platform level control valve assembly.
When I swap the electrical plug that actuate the control valve coils the controls are reversed but the platform continues to not rotate in the same direction. No change in direction of non rotation with the controls being reversed.
The ground controls produce the same results in all cases
I swapped the platform rotate relief valve cartridge with the platform level cartridge with no change.
When the plarform attempts to rotate the pump pulls hard and the appropriate line to the actuator moves with pressure. The platform will spring back.
It is like the line has pressure but the pressure is not allowed to go back to the reservoir.
I do not know what I am missing. Any help would be appreciated.

 

[Travs Thompson]

We checked the voltage from the function switch to the control valve controls. 13.64vDc
We checked the pressure coming from the control valve at the platform rotate actuator motor. More than 1000 psi on each line when control valve is actuated.
We swapped both ends of the hydraulic lines servicing the platform rotate actuator motor assemble and the main control valve assembly to rule out a damaged line that would only allow fluid to flow one way. No change platform will not rotate to the right.
We blew out the ports from the control valve to the platform rotate check valve and from the control valve to the fittings connecting the hydraulic lines to the platform rotate actuator motor. There were no obstructions, again no change of condition.
We changed the control valve a second time using a control valve from the boom extend/retract(same part #) boom extend retract works with the previous platform rotate control valve and the platform will not rotate to the right with the swapped valve. Have tried 2 other valves known to operate from other functions. Still will not right rotate unless i swap the lines at the platform rotate actuator motor then the platform will not rotate to the left.
If we crack the not pressurized line at the platform rotate actuator motor the platform will rotate to the right dumping the oil in a bucket. This line of course has to be tightened to rotate to the left as this is the pressurized line for the left rotation.
Any ideas would be greatly apprecated I now do not know any other sets to take

 

[djking]

I have this same exact problem. Tried everything you did too. Did you figure out what was wrong?

 

[Chris Carver]

DJking or Travs Thompson did you ever figure out what the problem was? We have a lift doing exactly the same thing, we have tried all of the same stuff...

 

[Chris Carver]

We checked the voltage from the function switch to the control valve controls. 13.64vDc
We checked the pressure coming from the control valve at the platform rotate actuator motor. More than 1000 psi on each line when control valve is actuated.
We swapped both ends of the hydraulic lines servicing the platform rotate actuator motor assemble and the main control valve assembly to rule out a damaged line that would only allow fluid to flow one way. No change platform will not rotate to the right.
We blew out the ports from the control valve to the platform rotate check valve and from the control valve to the fittings connecting the hydraulic lines to the platform rotate actuator motor. There were no obstructions, again no change of condition.
We changed the control valve a second time using a control valve from the boom extend/retract(same part #) boom extend retract works with the previous platform rotate control valve and the platform will not rotate to the right with the swapped valve. Have tried 2 other valves known to operate from other functions. Still will not right rotate unless i swap the lines at the platform rotate actuator motor then the platform will not rotate to the left.
If we crack the not pressurized line at the platform rotate actuator motor the platform will rotate to the right dumping the oil in a bucket. This line of course has to be tightened to rotate to the left as this is the pressurized line for the left rotation.
Any ideas would be greatly apprecated I now do not know any other sets to take

What ending up being the cause of this???

 

[Chris Carver]

I have this same exact problem. Tried everything you did too. Did you figure out what was wrong?

Did you ever figure it out??

 

[djking]

Did you ever figure it out??

I ended up putting a whole new valve on and opened the bleeder screws on rotator to get the air out. It is working so far

 

[92U 3406]

Have any of you connected the JLG tool and tried turning up the lazy function? The function speeds do need adjustment from time to time from my experience.

 

[Chris Carver]

On the bottom of the Main Valve block. Where the two hoses connect to the rotate function, there are two check valves that look like JIC to ORB adaptors. These are actually a "check valve/restrictor". We found one of ours was deteriorated/ failing and needed to be replaced. We had tried everything attempted in this forum including swapping pumps and valves and several other things with no luck.

I hope this helps!! Pictures attached are the hydraulic schematic and parts list (the only place in the manual that mentions these checks)

 

[Chris Carver]

Have any of you connected the JLG tool and tried turning up the lazy function? The function speeds do need adjustment from time to time from my experience.

Yes we tried this as well. Had them turned up to 100% with no effect.

 

[Sparkey308]

I'm having the exact same problem, platform rotates to the left but not the right. 2012 Genie Z45/25ic. I'm currently checking everything mentioned in this thread. Thanks for posting.

 

[Chris Carver]

On the bottom side of the valve body there are two restrictors (PN: 4641282) where your hoses connect to it. [they look like a simple adaptors JIC fitting to Boss] we found one completely collapsed and the other partially. I would replace those; doing this fixed our issue. Hope that helps!

 

[Sparkey308]

On the bottom side of the valve body there are two restrictors (PN: 4641282) where your hoses connect to it. [they look like a simple adaptors JIC fitting to Boss] we found one completely collapsed and the other partially. I would replace those; doing this fixed our issue. Hope that helps!

thanks Chris, I took it out and there was a piece of debris in it. Previous owner had changed that hose and must have gotten trash in it. Works perfect now.

 

[ScottP]

THANKS GUYS I THINK THIS MIGHT HELP ME OUT WITH AN ISSUE I'M HAVING WITH A SNORKEL 460SJ INTERMITTENT PLATFORM ROTATE SLOW OR NOT FUNCTIONING AT ALL