atg215
Member
Hi I recently had my hydraulic cylinder for my grapple bucket repacked and now it does not extent with any power.
I apologize for any incorrect terminology I am new to heavy equipment.
Background
I recently bought a 2004 NH LS170 and with it came a single cylinder grapple bucket. Upon receiving the LS170 the grapple was strong (could easily move multiple railroad ties and pull them together and pickup multiple), however there was a small leak in the front seal of the cylinder so I decided to get it repacked. I used it a little and it blew a hose before the repack (if i remember correctly it was slow to open the grapple, retract the cylinder, but powerful on close, cylinder extension). I then got a new hose and took the cylinder for repacking. The cylinder was repacked and was very weak on extension (close of the grapple) so I returned to where it was packed and it appeared the piston oring gave out. It was repacked but the problem persisted, I went back and was assured that this time the pack was good (took apart and orings were fine).
The problem that exist is that the grapple is powerful on open (cylinder retraction) but slow and very weak on close (cylinder extension) (which may be the reverse of how it was when I originally received the grapple). It can no longer move a single railroad tie let alone close hard enough to pick them up. I have tried to bleed the cylinder on install (tilted grapple down left the back hose cracked and watched as air and foamy hydraulic fluid came out while tapping the cylinder and then closed the system once the fluid appeared to no longer have air). Do i need to bleed both lines? I have attached a picture of the cylinder for reference (it is a single cylinder grapple with the cylinder sitting in the middle). Any help would be hugely appreciated.
I apologize for any incorrect terminology I am new to heavy equipment.
Background
I recently bought a 2004 NH LS170 and with it came a single cylinder grapple bucket. Upon receiving the LS170 the grapple was strong (could easily move multiple railroad ties and pull them together and pickup multiple), however there was a small leak in the front seal of the cylinder so I decided to get it repacked. I used it a little and it blew a hose before the repack (if i remember correctly it was slow to open the grapple, retract the cylinder, but powerful on close, cylinder extension). I then got a new hose and took the cylinder for repacking. The cylinder was repacked and was very weak on extension (close of the grapple) so I returned to where it was packed and it appeared the piston oring gave out. It was repacked but the problem persisted, I went back and was assured that this time the pack was good (took apart and orings were fine).
The problem that exist is that the grapple is powerful on open (cylinder retraction) but slow and very weak on close (cylinder extension) (which may be the reverse of how it was when I originally received the grapple). It can no longer move a single railroad tie let alone close hard enough to pick them up. I have tried to bleed the cylinder on install (tilted grapple down left the back hose cracked and watched as air and foamy hydraulic fluid came out while tapping the cylinder and then closed the system once the fluid appeared to no longer have air). Do i need to bleed both lines? I have attached a picture of the cylinder for reference (it is a single cylinder grapple with the cylinder sitting in the middle). Any help would be hugely appreciated.
