Howdy! First post. Not a pro by any means when it comes to heavy equipment but I try my best. So to help you help me I'll give you some brief history. 2012 I bought this 1981 Case 680H backhoe. I looked at it and could tell it needed some TLC. Boom cylinder was just starting to leak and front bucket was way under power. I got under it and immediately noticed a little drip from pump shaft seal. Beat the guy up on the price of a new pump and bought it. Ran it for about 3 months like that before the pump finally went. New pump in, topped off fluid and back to digging I went. Digs like a beast! I moved some big stuff for the next year. About 2 months ago the boom cylinder started leaking more. I couldn't take the machine down right away. I let it sit for about 3 weeks then the time came for the very last part of my project. Here's where the trouble began. Backed the machine up to the rock. Dug perfectly fine. Swung the boom to the right...back to the left...then the boom swung itself back to the right on it's own. I swung it back left and it swung itself back right again. Repeat a few times and then it stopped going to the right altogether. Luckily I was finished doing what I needed. So I got under it and couldn't find anything else leaking except for the boom cylinder. Checked the fluid and it was very low. So...I decided now was the time to do an oil change and get the boom cylinder fixed. Got the boom cylinder repacked and back on. Filled the reservoir with oil and started it up. Boom works perfect no leaks. Tried to use the swing and it still will not go right and now barely goes left. Checked the linkage and it seems to be lifting and dropping the proper distance in the valve. I did notice this though...I can get out and push the boom to the right by hand. I asked two guys I know with more experience than me. One is guessing the relief valve on the back of the cylinder(s) and the other is guessing one of the cylinders itself. I'm almost thinking it's the valve but I am green to working on hydraulics. Can any of you resident experts help me through this before I start pulling things apart that I shouldn't? Thanks in advance. I appreciate any honest help. I'm somewhat mechanically inclined and confident I can fix this if someone can point me in the right direction of WHAT to fix. I'm not the kind of person that just likes (or can afford to) throw parts at something till it works.
Welcome to HEF backroads! If the control lever feels perfectly normal ie: no sloppiness / no tight spots. I would be stripping the cylinders - LH first, if that OK then RH. There are reliefs screwed into the rear of each cylinder, you could pull them & see if anything is stuck in them first, but my money is on a bad cylinder.
Thanks for the tip alrman! Going to sleep on it today. When you say "left" cylinder, is that left from looking at it from inside the cab?
Yes, all Case backhoe left & right descriptions are from the operators seat in the operating position.
:thumbsup Thanks for taking the time to explain to a Newb!
Alrman's advice is the thing to do , but I would plan on resealing both of those swing cylinders. If one of them has failed that badly it is only a matter of time until the other one will fail. It will save you a lot of down time with the machine and another seal kit purchase. Also those cylinders can be resealed on the machine if you plan on resealing them yourself. Great caution must be taken when unhooking the boom swing cylinders because you can get injured if the boom is allowed to swing freely.
Thanks for the tips!! I guess the next step is to order 2 seal kits. Anyone ever get any off of Ebay before? I don't have a local Case dealer nearby.
Case 680H won't swing UPDATE Well...I took the advice you all gave me and started in on the left cylinder today. As soon as I popped the pin out I immediately new I had found the problem. Got it all apart and here's the result.
Those cylinders are a lot easier and faster to service with them on the machine. Any full service hydraulic shop will cut the eye off your broken rod and weld it onto a new one. At the same time they can install the new seals. I went through the same situation not long ago. It cost me $400.00.
You may also need to find the cause of the rod bending. It looks like it was flexing/stressing in the tube between the gland and piston causing the brake at the threaded end. I would check your pins and bushing in the tower and the swing mounting. Also check the relief pressure in the swing relief valves.
If cost is an issue, you might want to check with a machinist, the hydraulic shop might just sub the work out to him anyway. I had two bigger metric rods replaced for less than $400, eyes cut and re-welded and the rods machined, I did the piston seals. I agree, that looks like a strange way to break. Could you post a close up picture of both broken rod ends, so we can see what the grain looks like? Might show something? Put a straight edge on the rod and see if it's bent also.
I did take the cylinder apart in the machine. Once I got the rod out I couldn't get the piston out. It was all the way in there and I figured I may replace the whole thing so I removed the cylinder. Looking around I see I can order a new Rod for about $200+shipping. I already have the seal kit. Will try to get more pics if I remember. I'm kind of dead in the water till tomorrow when everything opens back up tomorrow. As for a local shop. They do all their own Rods and Machine work. The only issue is how far behind they are in work. The last cylinder they did for me took over 3 weeks to get back because of their backlog and technicians on vacation. I don't know of any companies in my area that will do a service call. Also, from what I can tell the pins look ok. I agree it is strange for it to break...but I've been moving some big rocks. Probably a big contributor to the rods failure. Thanks again for the help. Will keep you posted on my path forward. Here's a couple pics of some of the rocks I've encountered.
I forget on a Case you can just order parts. Does the bolt hole go back to the break? that would explain a lot. Take that piston off before you order a new rod, just to be sure you can get it off in good shape and don't need to order more parts.
The break. I already planned on getting it apart before I order anything. Thanks again guys for your guidance!
And the rod looks pretty straight.
That relieves my concern about the something bad causing the break, I wonder why they used a big hollow bolt to hold that piston on? Looks like red locktite to me on the threads? If so, I'd stick that baby in the oven at 350 for an hour then pull it out, add some refrigerant (co2, propane etc.) to the hollow bolt, put the broken rod in a vice and see if you can break that bolt loose. OR weld the broken stub of the rod to a suitably stable chunk of I beam or whatever you have around (if you use your front bucket, disconnect the alternator first), and then take the breaker bar to the bolt. Both done as quickly as possible, strike while the iron is hot so to speak. The idea is to heat the rod hot enough to soften the locktite and have the bolt somewhat cooler than the rod to be looser and hopefully easier to break loose.
Not sure either. But there is a small rod, ball and spring that was inside the rod I guess? I say guess because it was laying in the bottom of the cylinder when I got the cap off. Haven't found this in any of the drawing. :beatsme
The ball is used to control/seat the spring in the rod & the plunger is used to cushion the swing of the hoe.
That is part of the swing cushion relief, ball, spring, plunger.
Well alrman's pic shows it 17/18/19.
thanks a ton!!!
Ok, so I was able to get it apart today. Just welded it to a piece of angle iron and hit it with the impact gun till it spun free. Already have the seal kit so I ordered up a new rod. $215 delivered. Will be here Wed or Thurs they say coming from Ohio. Going to clean everything up and get the new seals in the gland and be ready to slap it back together when the new rod arrives. Thanks again for everyone's help. You made doing this very easy for me.
I did call the local repair shop. They said they get $87.50/hour to "make" a new rod and that there was no way they could make it in less than 2 hours they said. The repair man actually recommended I just buy the shaft instead to save money.
I just wanted to check with you resident experts. This is the correct orientation for the spring rod? Got all the new seals ready to go.
Be sure to get those seals installed facing the correct direction. Also do not allow the seals on the gland to drag across the threads in the barrel.
all seals went in the same direction that they were facing when they came out.
Well nobody has replied about the orientation. I think this is correct according to the drawing so that's how it's going to go together today. (fingers crossed)
Just got the new shaft off the big brown truck. Looks like they updated it and it no longer has the spring, ball and rod as part of the set up. Time to get it together.
All back together and works fine! Thanks everyone for the help!
No news is good news! What the???? The spring & plunger are required to cushion the swing - you can't just leave it out. Did you get this from a Case dealer? Do you have a part number of what was supplied? Are you sure it's slowing down at the end of the swing to the left? Your Welcome :drinkup
I ordered it by the case manufacturing number. I looked at the inside of the shaft where it was drilled and there was definitely not enough room for the ball, spring and rod.
Original part number was G34775 & it has subbed to G110166 - was one of these numbers used? What is the number of the rod that you have fitted? Note - even though the number has changed does not mean the design of the rod has changed .....
G110166 is what I ordered. Trying to upload/post from my phone.
That's very strange - did you call the place you bought it from? & explain the difference? Was it a CNH dealer? As far as my knowledge goes, the spring & plunger would have to still be used :beatsme Does the swing slow down at full LHS? Be Carefull!
Haven't run it much yet. Will call tomorrow. Also I will be extra careful on swinging.
It can't possibly be fine if you installed the hollow bolt and left out the spring, rod and plunger. I think that boom and dipper is going to be real scary when it is extended all the way out and swinging fast.
I didn't install the hollow bolt. The rod came with a new bolt and washer. As for swinging real fast...that's something I've never done. I do appreciate you concern and am taking your words of wisdom to heart. Y'all got me really worried now.
Now we have the rest of the story Without the cushion capability be carefully to not let the cylinder bottom out. It will be tough on the cylinder and boom.