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Volvo 330B LC dipper arm cylinder piston removal

dewbee ยท 2026-01-03 18:10

serial 10580 Trying to remove the piston from the dipper arm cylinder. Was able to remove the lock nut without much trouble but the piston on the other hand will only move about 90 deg before stopping. Lock "nut" was reverse thread so piston should be standard although Prosis claimed both ways depending on where you look. Prosis claims my serial number is upgraded with red LOCTITE 277. I've heated it without out any success. Does anyone happen to know what size SKF TMFS socket I would need or some other type of tool? I've tried a spanner without any movement and got the most movement using "4 bolt cylinder head wrench".

Replies5
  1. #1heymccall2026-01-03 18:17

    On the EC160B arm & boom cylinders that I just did, the locknut was LH thread, then the RH threaded on piston had a set screw that had to be backed off prior to piston removal. Or maybe the set screw was on the locknut?

  2. #2dewbee2026-01-03 18:27

    yes "3" is the lock nut which is held in by a set screw. all that removed without much effort. "15" the piston is what I can't get off.

  3. #3dewbee2026-01-05 17:28

    Update. Took it to a hydraulic shop 2 hours away that I've dealt with several times over the years. I normally do my own but sometimes get to busy, ect. They tried to get it off while i was there but they could only get it to move about 1/4" or less than me. Metal flakes were falling off in the process. This is the first time the cylinder has ever been off this machine. Thinking it was cross threaded at the factory. Looking at cutting off the piston but going to cut off the cushion first in hopes we can clean it out from the back side were metal was falling out in hope to not have to cut the piston. Looking for parts VOE14503565 (piston) and VOE14509076 (cushion) just in case. I can't find anything online. Volvo claims they don't have any available at all. Any help would be much appreciated. Im just an idiot that bought it to clean up a small tract of land in my spare time.

  4. #4HarleyHappy2026-01-06 11:07

    Okay, so I can understand why you want the piston off the rod but can you rebuild the cylinder and replace the seals on the piston, without taking it off the rod? Never mind, brain dead moment. Whats leaking on the cylinder? Depending on what a piston costs and availability and what was leaking, you could always cut off the rod eye and weld it back on. Have had to do that on one cylinder that parts were unobtainable for.

  5. #5dewbee2026-01-06 13:55

    Just about all of the seals need replacing. So piston has to come off. Volvo claims they dont have any pistons available. Rod eye might not be a bad idea but since there's metal coming out on the piston side, it needs to come off otherwise there's going to be metal in the hydraulic system