Hello. So I am out of of own getting major dental work done for a few days. My operator calls and says the main book hydraulic cylinder is leaking. He says it will be ok if we add fluid...but it's leaking. The one next to the cab window. So, my question is....I have built many cylinders. Not usually larger ones.... I have 5000 hours on this machine. It's pretty nice and tight. I noticed cylinder weeped a little after it sat for 6 months after running it a while....it quit leaking. But now it has come back. What process should I take to build e cylinder? I have ideas of how I might do it...but I wanted to put the question out there on this to see if I can learn something and gain some tips and tricks. Also, should I buy the packing lot from cat dealer? Any idea on the part number? Cost? Also what is a normal mechanic cost to rebuild this cylinder? Time frame? Would I just take the cylinder loose at the top of the boom and let it down level? Them take a spanner wrench(which I don't have can I make one?) and loosen the barrel nut. Slide the rod out a leave the barrel hooked to the machine? How do I torque the piston nut properly? A cheater pipe slid over the wrench? How do I know how many foot pounds I am pulling? As far as repair....should I pull the piston and rod out and haul it to the atlanta YANCEY dealer? Somewhere on Asheville? Chattanooga? Knoxville? I am centrally located. Thanks for any help guys? thanks!
For that size yes, I would pull the rod and take it in. Check for a local hydraulic shop. May be able to get it done cheaper for you. That said, you will get what you pay for. If a Cat dealer rebuilds it, They will stand behind the repair at least for a little while.
I suppose the question should be what size tools you have available. The head comes off with M20 Metric Allen bolts, only the piston nut is a large one. Many before you will have tightened piston nuts using a wrench fabricated from a piece of plate and whaling on it with a 14lb hammer......and many will after you. I've never had one come loose yet. If you have an independent hydraulic shop close to you ask about the cost having the cylinder resealed if you haul it in to them. Also price the cost of Genuine Cat parts versus "will fit". The difference may surprise you. I just priced seal kit for a 320B ANB Lift Cylinder (there are about5 5 different Part Numbers) and the price for a kit ranged from $250-$365 depending on the Part Number of the cylinder.
If you are going to take it to dealer, take the whole thing, to get a good job, if you put just a seal kit in that's what you have a resealed cyl. We like to hone the barrel, polish the rod then you get a nice finish. Lasts 3-4 longer. If doing one boom cyl, do them both at the same time, labor, travel time, all in one.