Komatsu FG30GT11:
Fork lift free lift problem

Hello. I have a 1995 fG 30 forklift. the free lift cylinder is only working after that the mast has fully opened. i took out the free lift cylinder and they is a hole at the bottom of the rod ( oil passage) and than just above the piston there are two holes that allow for oil to come out above the piston. Its a single acting piston. cannot understand what are those oil passages for?. isnt it supposed for the oil to only be under the piston seals in a single acting piston?.
thx
  • Posted 19 Jun 2016 21:01
  • Discussion started by bombo
  • minsk, Belarus
Showing items 1 - 1 of 1 results.
sounds like a fluid displacement cylinder.
They are commonly used in hydraulic systems on lifttrucks today.

They have a safety valve in the bottom of the piston located in center.
These valves can cause all sort of problem if they fail or become faulty. I have even seen the retaining ring come out and the valve fall out and be destroyed by the pistion.

Make sure it is present, if it is not then you will need to check bottom of cylinder for debris and remove it, then install a new safety valve.

The holes you see in the side of the piston are ports to allow fluid to flow 'a certain way' through the piston and safety valve.
  • Posted 20 Jun 2016 00:30
  • Modified 20 Jun 2016 00:31 by poster
  • Reply by swoop223
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com

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