Why would travel left go complete but travel right stops 10 degrees past center. If Movement is fast enough, the mast will swing past but the right cylinder stops retracting at the same 10 degree spot while left cylinder continues to expand and the chain goes slack on the right side of the center chain attachment point?
Smokeydog
Elite Member
That’s a multi link chain for swing. Hadn’t jumped a cog? Broken link jam? Had that piece of chain fail on me and had to replace.
LD1
Epic Contributor
Is the cylinder rod bent or some.other mechanical bind.
If the chain is going slack on the left side....even though the right cylinder stalls and quits pulling....there should be nothing preventing the boom from going on around unless there is a mechanical bind
If the chain is going slack on the left side....even though the right cylinder stalls and quits pulling....there should be nothing preventing the boom from going on around unless there is a mechanical bind
Smokeydog
Elite Member
Had shop manuals for the 4500. 7 separate books. The best well written shop manuals I have ever seen. Good sections on troubleshooting. Money well spent for DIY maintenance.
There are no cogs. The chain is bolted at the center point. No jamming to be found outside of the cylinder.
I will attempt to get these manuals. Other info. The two cylinders involved have only one line attached to them. They only retract by being pressurized on the rod end. They are then extended by tension on the chain that is applied by the other cylinder retracting. Both cylinders lines come through a valve body named Hydreco. My guess is this is where the problem lies. This valve is likely supposed to control the speed that the cylinders expand so that the boom is held in position. Evidently this system is too old for the shop I took this tractor to to understand. I need to find out how to adjust this hydreco valve. More research.
Smokeydog
Elite Member
Remember replacing a broke chain obviously not how attached.
There was some mechanical force to the swing lever to decrease swing speed near the end of travel. Cushion, safety and operational feature. Some sort of linkage or cam to the swing control valve? Is the swing valve fully being operated?
It could be an internal hydraulic problem but with troubleshooting checking the obvious and easy stuff first. Swapping the hydraulic lines given similar operation the other way? Might require some test hoses.
The 4500 was my first industrial backhoe. Bought used $4500, used 20 years and sold needing some maintenance $4500. The cleanest oil of any diesel I have ever owned.
There was some mechanical force to the swing lever to decrease swing speed near the end of travel. Cushion, safety and operational feature. Some sort of linkage or cam to the swing control valve? Is the swing valve fully being operated?
It could be an internal hydraulic problem but with troubleshooting checking the obvious and easy stuff first. Swapping the hydraulic lines given similar operation the other way? Might require some test hoses.
The 4500 was my first industrial backhoe. Bought used $4500, used 20 years and sold needing some maintenance $4500. The cleanest oil of any diesel I have ever owned.
LD1
Epic Contributor
Unhook the chain and see if the cylinder retracts fully
Yes there is a mechanical limit switch that backs the control valve off at the end of the swing but I temporarily removed it while I was troubleshooting. It allowed swing left to go a bit farther but swing right still stopped very short. Swapping hydraulic lines would help define the problem.
