I just bought a 1978 JD410. My first backhoe. I moved TWO buckets of gravel and burst a hose. Got it off with service wrenches I got at Harbor Freight, had NAPA build a new one, got it back on. That was last week. Got a few hours of heavy clay moving each day, then today, lost power digging out with the backhoe. It's leaking profusely from either a 90 fitting or a flare fitting right at what appears to be a non-original hydraulic pump. My question is how do I get this thing off? What kind of alien wrench do I use to get in there, or do I have to disassemble half the tractor to get to it? For context, I start with a wide angle of the tractor :
I think that's an O ring boss fitting, so that nut loosens up on the threads of the fitting taking pressure off the washer and the other threads, once the nut is loose the fitting should come out by hand. A crow foot socket/wrench is what you want from the looks of it, but you could probably take a HF box end and cut it open enough to make it fit and trim the handle, once knocked loose that fitting will come out easy. If you're dealing with a lot of leaking hoses and loosening fittings, try to keep the fluid from getting low, and if it gets foamy or milky looking from running, then it needs to be changed. The constant hammering from the closed center system will work fittings loose if there's air in the oil.
That could be my old hoe. Closed center is a different animal. Your pump is an eight cylinder radial design. There is a cam shaft pushing the pistons out. A spring pushes each in. The crankcase is pressurized. as pressure builds, the spring isn't adequate to overcome the pressure, the pistons don't move. They are said to be out of stroke. Valves when not in use are, like your home water system, closed. No oil flows, pressure rises to maximum, and stays. More of the system is under high pressure than an open center system. It makes for a smooth operating hoe, but leaks are more common, and spill more volume. Willie
Karl, I have the 410's big brother, the 510. I had a blow out on the same line you are working on. The set up is just slightly different but similar enough. The crow foot might be good but I used a simple open end wrench and came in through the top. I did have to move a few things out of the way to get in there and have enough room to flip the wrench and then had to bump it a little to break it free with a 8# hammer but once it moved I was able to work it by hand.
Forgot to add, you need to replace the o ring with one made for an o ring boss fitting, a regular o ring might, or might not work. It will be much easier to take out the second time though
Just a little more info, please? Thank you guys so much. You're a life saver! I tried to turn the larger nut, but now I think that's a swivel. I couldn't turn it even with a 13" breaker bar (largest I could fit underneath) So, is the smaller nut against the pump the nut that I need to be removing? Also, I found that a sheer pin had snapped and had fallen off the boom. On the other side, I see they used a bolt. If I get a hardened bolt, am I ok?
SORRY! I was wrong about the fitting. That's probably a flat face o ring fitting, but in any case, loosen the part marked swivel, not the part "is this the nut I remove" (that's the one I was talking about before, when I couldn't see the pic well enough) Please post a pic of the shear pin on the boom, I can't picture what that would be, and I already made enough mistakes in this thread.
I don't agree. I believe based on your picture that it is the larger nut you need to loosen. It is possible someone cranked the fitting into the straight o ring thread until it bottomed. Its intent is to screw the male fitting into the female threaded hole in the pump until it aims the needed direction, then tighten the nut to compress the o ring and seal. If that nut is jammed against the fitting you may have to loosen both at once. Find good tools, as you don't want to ruin the fitting. I might try a cutting torch to burn the nut away from the fitting. A skilled hand can burn away the nut without harming the male threads on the fitting. You'll need someone on fire watch with a halon extinguisher. Willie
Now what... Ok, so I need to turn that nut counter clockwise as if I'm unscrewing it off the threads going into the pump? Or clockwise, unscrewing off the angle fitting in front of it? Then what do I replace the whole fitting or just the o ring?
I'm sticking with post #7. In any case, you turn either of those nuts out counter clockwise. Whichever one is easier to get a grip on, or is looser. Replace both o rings as long as there's not obvious crack or corrosion where the o ring seals, there usually isn't. edit: if Willie and my first impression were right (they're not) then the big nut would be much easier to loosen than the smaller nut, and would not damage the o ring, which is going to be replaced anyway.
Ok, with a $31 Wrench from Sears, I got it off. And the burst is visible. Can someone tell me what this is called so I can search it on the net? Also, here are the pictures of the shear pin and where it goes, along with a picture of the bold used on the other side.
Delmer; I apologize. to me in the earlier picture it looked like a basic o ring fitting we often see in pumps. Out in light I see what it is. Willie
Where's the o rings Willie? I was expecting them too, I still think there's one between that big fitting and the pump. That fitting looks like a 16 JIC female to male 90 elbow. 16 means 16/16" or 1" nominal size which has threads of 1 1/4" in and 1 5/16 out. But measure it and look at something like this before ordering https://www.discounthydraulichose.com/v/vspfiles/downloadables/thread_guide.pdf Better yet, take it to a hydraulic shop and they'll get you one faster and cheaper than with shipping. A bolt is fine for holding that pin.
I would like to see the $31 wrench from sears! I will tell you that I have amassed a large amount of over sized tools since owning heavy old equipment and it never fails, you can own a pair of 15/16", 1", 1 1/16", 1 1/8", 1 3/16", 1 1/4" & 1 1/2" and you have to get into some trouble with your machine and then... WHAT! It's a 1 5/16"... I also have a 8# hammer I use to bump large bolt loose that I always have with me. And as far as a breaker bar, I have an old clothes line pole that I cut the top off. It has a flared end that I can slide over some, not all, of the big wrenches.
I wasn't kidding! it was a 1-3/8 X 1-7/16 Open ended wrench I picked up at Sears today: http://www.sears.com/craftsman-1-3-...p-00944588000P?prdNo=1&blockNo=1&blockType=G1
That bolt is not a "sheer pin". It's just a bolt to hold the boom pin in place. A sheer pin is a sacrificial pin on something like an outboard motor prop, snowblower auger/impeller or a tractor pto shaft that is meant to fail if the rotating shaft gets jammed on something to prevent the shaft assy from being damaged. Any hydraulic supply/repair shop will have your fitting, should not be very expensive.
Some might avoid using a bolt. It will get battered, any thread sticking past the nut, it will be hard to remove. I guess if there is room to turn a wrench, I'd use a lock nut, and cut the excess thread off. A clevis pin will work, but cotter pin keepers tend to be problematic too, I've lost a few in my time. A particular problem has been the pin on the butt of the cylinder on a thumb. I use a hairpin, and I've lost several. No obvious reason. The big pin where my thumb pivots at the end of the dipper stick I found the perfect keeper; electrical tape. The big pin was repurposed from a log grapple. I shortened it for the thumb. Attempts to drill it for a hairpin failed. In a hurry, I grabbed a roll of electrical tape, and put on several wraps. I intended to change it, but it has been great. I can remove the thumb with no tools. Losing the keeper pin is never a problem. Smashing the pin not a concern. I've always got a roll of tape handy. Willie
Ok, I went to a hydraulic shop, took it in, and they said it's bigger than a 12 and smaller than a 16. Must be a 14 (7/8") And they don't have that. Grainger doesn't even carry that. I measure across the threads and it's 1-1/4 OD. Now I'm searching online to find it. Help?
http://www.discounthydraulichose.com/product_p/6500-14-14.htm
Found one locally after 8 phone calls. I don't have the manual. Anyone know what kind of hydraulic fluid I need for this old jd410?
Tractor supply has a Traveler fluid for transmissions, and hydraulic. The spec # escapes me at the moment.
Don't use anything that says 303, or is less than $40/bucket. Traveler is probably fine, especially while it gets used as dust control regularly. Hyguard from the deere dealer is worth considering when you fix all the leaks and want to change it all out. This hydraulic system is shared with the transmission right?
Yup. Deere do everything fluid is recommended, gears, clutches, brakes, steering, hydraulics, common oil sump.