Hi guys, I know this is an old post but hopefully you can help me.I have had one of these 3 stage telescopic cylinders re-worked.
Took it to a hydraulic specialist who had all rams re-chromed,new seals made up.Fully stripped & re-built
When fitted back onto truck there seems to be an air lock that wont clear.Lifts to highest extent & holds.Okay until upper section is lowered into larger,outer section which will slowly drop an inch or so when lever is released.But then holds load.
There is a small outlet on top of main cylinder body (about 1/4 inch internal diameter with fine thread)
I think this is maybe a vent hole ,but there is no screw within ,but if a small screwdriver is pushed up the hole it is possible to feel a hole into the main cylinder body ,but nothing comes out.
I have tried fully extending ,up & down for about an hour but will not clear.