Any tips on rebuilding the telescoping boom cylinder. The cabling retract system seems like a nightmare to adjust. I believe my crane blew out the packings on the front end of the hydraulic ram. I was doing a water tank in a near horizontal position and I was booming out, almost fully extended and felt something pop and then a cascade of oil came running down the inside of the boom. I couldn't get the boom back in and it was fully extended and parked between some electrical lines. We ended laying the boom down to level and removed the holding valve cartridge, then winching the boom back in slowly with the hoisting control. Now am tasked with trying to rebuild it. I am very mechanically inclined but the boom cabling requires a tensioning tool with a lot of measurements. It is a 4 section boom with two stage hydraulic ram. Maybe I should get it done professionally. Has anyone ever attempted a National crane boom?
If you are not changing the cables or chains(don't know for sure what you have), just put it back were it was when you took it apart. The cylinder is long and awkward but not difficult to repack. The ones I have done had red loctight on piston nut and had to get serious to brake loose. You can take them out the top or the bottom if you don't need new cables or chains the bottom is the quickest just be careful to keep some tension on top rollers. Edit: once you see the cable system it make sense just adjust slack for even pull.
I've always done it like caveman suggests, I measure how much thread I have sticking out of each nut on the cables, and put it back like it was.