I am about to embark on replacing seals on most of the hydraulic cylinders on my old 580CK. I need to buy a big-socket-set, but don't know (even after looking at the manuals) what size the nuts on the cylinders are. Figure buy a set of big sockets now that will do them all. I know the swings are 1-7/8. Anyone know what the other cylinders on the loader and backhoe would typically be??? Should I get 3/4" drive or 1" drive sockets? I know I'll need to use a long cheater bar to break them open. Also, mine have the relief valves sticking out of the nut (on the swings). Do you use a deep socket or just use a standard socket and push on the valve while wrenching it? Thanks in advance. --- Tim
I recommend taking the cylinders off and to a reputable hydraulic repair place that has the proper table to repair the cylinders. They have the tooling required to disassemble and reassemble without heating which causes other issues. I have fought these things before , by the time you buys tools etc. its cheaper to pay the man for what he knows to do.
1 inch drive sockets will do the trick anything up to 2 inch should be fine... I dont recommend heat of any sort. Cheater pipes work wonders breaking them loose. Make sure to lock tite them and make them tight again. Lots of lubrication when installing the new seals as well. I would not tackle the job unless your really comfortable doing this.
Read some of the threads about bad experiences with hydraulic shops before you decide to turn them over to somebody you don't know. They're pretty simple, just heavy and have a few tricks. If you run into a problem, just ask. 3/4" made in the USA, or 1" Chinese your choice.
Only one I've ever struggled with is the main boom, its 2 and change, 2 1/4 maybe? I had to anchor the eye end between two blocks under the dozer track, the big air gun didn't want to spin it until I warmed it up a bit, 2 different machines had some loctite on there. 800ftlb only needs a 6' long bar.
thanks for all the advice everyone. I have a 1"-2" set on-hand now, and a Wright 1" breaker bar coming. Tim
I only have a 3/4" set and cheater bars. So far I have been able to loosen the piston bolts with no problem. I recently gave up trying to get the gland nut loose on one of my cylinders. Took it to a "reputable shop" to get it open. I figured they had a better peg wrench than mine and a table/machine to make it happen. They used an oversize pipe wrench, 3 men, and an 8 foot cheater bar. In hindsight I should have spent that money on a large pipe wrench and enlisted some more help. I agree that heat is a bad idea. I tried it on both of my stabilizers. The first one didn't come loose till it cooled back down and I never got the second one loose. Funny thing is I had resealed the second one a few months earlier and had no trouble removing the gland nut. It started squealing and operating slow which I thought might be the piston seal bypassing. I was the person that tightened it last and it would not come back loose no matter how much cheater and help I had. At the end of the day I didn't need to redo that cylinder but needed to replace the fluid control box mounted on it.
If red Loc-tite was put on them its gonna require heat to melt it or you will never get the nut or bolt loose. Maybe Mikebramel will read this and give a pro's opinion.
I never had trouble taking the bolts off with lock tite on them. My scronny 120 lbs but would break them loose with an 8 foot pipe
Evidently finding a good hydraulic shop is hard to do in some areas. I know my tilt cylinder on my track loader , the piston nut torque was around 3500 ft/lbs. I don't like heating these things. That's why I took it to a guy that has the bench set up to remove the nut. It uses a 70 ton port a power and the "wrench is 1" think plate. 250$ later the cylinder is disassembled , cleaned honed , cleaned again and assembled. Then he cycles it with a pump and 10W oil that is filtered. Takes about 3 to 4 hours to do this. But I have had bad experiences with getting these things loose.
Yes, standard practice to put at least blue loctite on the threads of any backhoe as most don't have any cushion on the cylinder or very quick acting port reliefs. When the bolt isn't locked and tightened properly they do back off and get stretched out, the piston goes crooked to the rod, ..... pocket book down hill LOL. I would consider heating the area the area of the rod in front of the piston almost a necessity, but you can do what you want. If there is loctite on the threads and you put a good amount of torque on it and are working against that you are definitely putting unnecessary stress on the bolt head. The piston bolt heads are usually 1-5/8, 1-3/4 and 1-7/8. I'd go with the 1" drive as 3/4" is only rated for 1200ft lbs. Just support the end of the rod where the piston bolt screws into when you are "pressing" down your "breaker bar"
Rebuilding the cylinders is quite doable. I have done several and the toughest one for me was the outrigger as the end of the tube was oval shaped from years of use/abuse. The spanner wrenches to remove the gland nut was the key to success for me. I had to make custom ones for each cylinder I've done on my 71 CK but was well worth it. I usually leave the cylinder mounted to the tractor and pull the pin on the rod end for access. Remember to look for a little screw (8-32 x 1/4 or similar) that locks some of the gland nuts on. Not all but if there needs to be removed. Leaving the cylinder in the tractor is the best way I've found, to hold the cylinder from turning while you loosen the gland nut. Don't completely remove it until you can catch the fluid. I've done 2 now without taking the body off so no need to disconnect any of the hoses. Then once I get the rod out of the cylinder I remount it back onto the tractor and loosen the big bolt from the inside using a big socket or large 16" adjustable wrench with 4' pipe. Sometimes a longer pipe. That bolt inside that connects the piston stack to the rod has never been as much stress as the glands. Good Luck and post pics of your progress. For fun pics when I did the outrigger cylinder see my posts here: HeavyEquipmentForums