stondad
Well-Known Member
A few months ago, I replaced the quad rings on the spools to stop leaks, and the o rings and back up rings on the service port relief valves to stop functions from creeping up, on our 648E dual function log skidder.
I got success and a pat on the back, but my fame turned sour when some of the creeping faults returned shortly after the machine went back to work.
I explained that we had used local duro-70 o rings and cheap teflon back ups and I wasn't surprised that some didn't last long.
So I got my way and we ordered genuine JD parts and was immediately vindicated when kit P/N AT171175 for the nose of the service port relief valve containing just one o ring and two back up rings came up as approx AU$45.00 ea. So they are very special.
Imagine the ruckus when I wanted an extra two of everything to allow for "troubles".
The job is only moderately successful because I still have a couple of creeping functions.
One is almost certainly due to some of the high pressure o rings for the hex end of the service port relief valves being missing from the shipment so I used the best old ones.
NOW TO MY REAL PROBLEM.
The rotate still creeps around when it is empty.
I am suspicious of a couple of things which could be resolved if only I could get an accurate parts view of that slice of the control valve.
Hitachi Construction Equipment, who handle John Deere Skidders in Australia have bent over backwards in "parts" and "product support" to find the correct drawing but are so far not successful.
So I throw this open to the world!
Please refer to the two attachments or PDF's (however they come down).
The schematic of the system (dual function) is our machine, except that the adjustable service port relief for the grapple is shown on the top and ours is in the bottom (maybe changed to make it easier to adjust).
The cross section of the rotate spool slice is the right brand etc. but not what we have, yet it is the only one they can throw up for our machine.
Ours has no "locking piston".
Instead it has "load check valves" or "lift Valves" at the point of the service port relief cartridges, the same as all the other sections, which are poppet valves, nose into the pressure gallery, so it can't be something stupid like just that the "piston" is missing because there would be no seat in the valve body for the poppets.
I could describe more but my head hurts now and anyone who can help will probably have the idea by now.
Serial No. 648ET 539987
Numerous owners but it came from Tasmania, Australia, where we assume it started as a new machine, but not necessarily sold through an Australian supplier.
Thanks to anyone who reads this far.
OoooowKaaaaaaaaaaaay.
The files are too big to attach with my limited ability in this area, so I can email them if you are interested. Sorry.
I got success and a pat on the back, but my fame turned sour when some of the creeping faults returned shortly after the machine went back to work.
I explained that we had used local duro-70 o rings and cheap teflon back ups and I wasn't surprised that some didn't last long.
So I got my way and we ordered genuine JD parts and was immediately vindicated when kit P/N AT171175 for the nose of the service port relief valve containing just one o ring and two back up rings came up as approx AU$45.00 ea. So they are very special.
Imagine the ruckus when I wanted an extra two of everything to allow for "troubles".
The job is only moderately successful because I still have a couple of creeping functions.
One is almost certainly due to some of the high pressure o rings for the hex end of the service port relief valves being missing from the shipment so I used the best old ones.
NOW TO MY REAL PROBLEM.
The rotate still creeps around when it is empty.
I am suspicious of a couple of things which could be resolved if only I could get an accurate parts view of that slice of the control valve.
Hitachi Construction Equipment, who handle John Deere Skidders in Australia have bent over backwards in "parts" and "product support" to find the correct drawing but are so far not successful.
So I throw this open to the world!
Please refer to the two attachments or PDF's (however they come down).
The schematic of the system (dual function) is our machine, except that the adjustable service port relief for the grapple is shown on the top and ours is in the bottom (maybe changed to make it easier to adjust).
The cross section of the rotate spool slice is the right brand etc. but not what we have, yet it is the only one they can throw up for our machine.
Ours has no "locking piston".
Instead it has "load check valves" or "lift Valves" at the point of the service port relief cartridges, the same as all the other sections, which are poppet valves, nose into the pressure gallery, so it can't be something stupid like just that the "piston" is missing because there would be no seat in the valve body for the poppets.
I could describe more but my head hurts now and anyone who can help will probably have the idea by now.
Serial No. 648ET 539987
Numerous owners but it came from Tasmania, Australia, where we assume it started as a new machine, but not necessarily sold through an Australian supplier.
Thanks to anyone who reads this far.
OoooowKaaaaaaaaaaaay.
The files are too big to attach with my limited ability in this area, so I can email them if you are interested. Sorry.