So the bucket cylinder is stuck in the fully extended position. The bucket setup is also pretty janky / improvised and caused the ram to bend at some point and also allows the ram to hyperextend. I chained the bucket to the undercardage and raised the boom while operating the bucket tilt lever to see if it would retract, it does somewhat but seems stuck and then goes back to fully extended. Fyi the bucket curl has had a drift. When i try both levers, i see flex in the curl function but not any that i can tell in the extend function. Im wondering what possible causes for this and how i can narrow it down / testing procedure. Id really appreceate some help as we are running into a winter deadline with this project and we really need this excavator working. thanks
Might help if you tell us what the machine is and maybe include some pictures. We don't know if this is a 2 ton XCMG or a 6015 Caterpillar.
sorry its a john deere 493d originally wirh a tree shear but modified (badly) to have a bucket. its missing the normal linkadge to operate the bucket and instead has the ram directly attached to the bucket in a way that allows the ram to bend itself when at full extension. once i get the hydrolics figured out i will mofify the bucket mount and add limit stops so it dosebt do that, but im mainly concerned with finishing this job which should only take a couple more days. i may try and use the auxillary hydrolics to operate the bucket as they still work
Ewww. That’s gonna hurt!
better pic now that its light out
Send a picture of the lines in the cylinder please. A Case backhoe uses an over extended cylinder to engage the lock on the backhoe. From what little I can see of the cylinder so far, if the ram inside the cylinder has passed the inlet hole, the hydraulics will try and hyper extend the cylinder. I think your hydraulic system is working against you.
You would need to remove the fitting or break it free real good and find a way to get the ram on the other side of the fitting. Really need to add a stop in for that because your ruining the cylinder.
That cylinder bore is likely trash. I would hate to contaminate the forestry control valve as well. I think a quick cylinder bypass/internal leakage test would answer your questions.
oh so its likely that the debris from the cylinder bore jammed the valve? yeah thats more concerning. i did swap the lines and it will now extend but not retract, so i guess this confirms that the valve is the issue. probably the main valve then? seemed from the manual that this is a pretty major undertaking to lift out and rebuild. one note is that i pulled just the retract hose off to see if it would get any fluid when the controlls are operated, and fluid flowed out of the cylinder port on the retract side so i suppose this also confirms the bore is trash? the other option i was thinking is since half the basement is dug already i could just use the excavator with bucket extended to cut down the bank and use the skid steer (its a 100hp tracked machine) to load the dirt and level out which i will be doing anyway i appreceate the help, getting pretty stressed about this and its my first venture into heavy equiptment, i obviously shouldnt have bought this machine
It looks very badly worn out. Undo both fittings wher the hoses attach to the hydraulic cylinder and then use "somthing" to pull the bucket back into place, just enough to get the piston between the two hose inlets on the cylinder. NEXT, find a used H link and install it where it should be, otherwise your eventually going to have to replace the whole works. Maybe its at that point now, depending on how much you use it and what for. Good luck!
yeah its a mess. the plan was to buy a machine, do our dig then sell it
If you determine the bucket spool in the main control valve is actually stuck/jammed with cylinder debris. Remove the top and bottom spool caps, and the 2 bucket cylinder hoses. Stick magnets in the cylinder delivery ports to catch any debris as you pull/ push on the spool to try and free it up. I am confident you will be able to remove the spool. Flush the spool bore with clean oil and test fit the spool checking that the spool slides smoothly from top to bottom. Repair the cylinder, flush the lines and hoses,clean the hydraulic tank and suction screen , replace all the filters and pray. If you have any intention of keeping the machine you will need to install proper bucket linkage as @Chiefdug suggested .
Isn't the cylinder just wedged and stuck as it passed "over center"? In the position it is in, it has to extend even further for the bucket to uncurl. did you try pulling open the bucket with your chain as you moved the bucket stick in the "bucket curl" direction?
originally i tried that but it didnt work. i ended up switching the lines and the reverse problem happened (would retract but not extend) but it did unstick itself
thanks for the info, the caps are the two bolts that come in from the top above the stacked valves? the bucket did get unstuck on its own. we are really running into a deadline with this dig so even though im aware of the risk, im going weld on some limit stops and dig the rest which should only be a couple days of digging. then i will take it out of comission and decide if we want to go the repair route or sell it with a heads up to the new owner on the issues. i appreceate your help.
I assume the bucket hydraulic circuit was supplied by the main control valve not the forestry control valve. See 2 screenshots below of the main control valve with spool caps identified.