Just had the double cylinder in the boom rebuilt, installed everything and hoses but cylinders will not move. Do I need to bleed the cylinder?
Shouldn't need to bleed the cylinders but could the hoses have been hooked up backward, instead of lifting it's trying to retract? Other thought is maybe load checks are stuck and not allowed fluid to flow through them. I bet CraneOp would have an idea.
Usually you just have to cycle them few times and any air will work its way out. I did one time have the dual boom cylinders rebuilt on a grove tms300 and when I reinstalled them one of the cylinders was moving really slow and fighting the other. I had to adjust the pilot check valve on one of the cylinders to get them back to opening at the same hydraulic pressure. The hydraulic shop claimed they didn't do anything to the check valves and maybe they didnt but something about the rebuild changed the pressure required to open the valve.
I was thinking something about the same.
Sorry for the late reply, machine shop had problems moving both cylinders when they tested them after they repaired them and did something. Told my boss that it needs a hose to the counter balance valve but there was only the two 30ft hoses that we disconnected. These cylinders extend and contract the boom so it shouldn’t have anything to do with the counter balance valve that controls the load?
There are check valves/load checks that prevent the boom from falling if a hose fails. That's where we think there might be an issue.