Hello everyone, I'm new to all of this and new to this machine. I just purchased a 1986 john deere 410c 2wd backhoe and am having some issues sorting it out. It's my first piece of heavy equipment, and I'm now being forced to learn quickly about hydraulics in order to figure this thing out and get it running properly. So please have some patience with me, I don't know all the terminology, and am picking this up as I go. The backhoe simply lacks power, specifically on the hoe end of things. It won't dig a hole, everything seems to move quickly from opening to closing of cylinders without load, but with a load just doesn't have nearly the power it should. The outriggers will pick up the back end of the machine off the ground, but not to thier full extension. the second boom on the hoe will dip the bucket in the ground but will not pull strongly enough to make a hole or move the machine. The front end will also pick up the machine off the ground but not strongly. So..... my first thought was (crap) it's probably the pump, and since I can't afford to take it to the dealer I'd better start figuring this out before my wife finds out I bought a piece of crap. I went and purchased a guage and line, tested the pump on the front port and read 2700psi (whew) relief, so I then removed the hose to the second boom cylinder and tested the pressure from the extend (pull in second boom) hose, and again 2700psi (ok good). So I figured it had to be the cylinder itself. Just to be sure I removed the opposite line from the cylinder and bottomed it out applying hydraulic pressure, and sure enough, fuild came out the port on the cylinder. So I figured for sure that the cylinder must be bypassing the piston seals internally. Tried the same for the bucket cylinder, and again same thing. Removed the two cylinders, took one apart, then brought them in to be rebuilt. Eventually I got the cylinders back, replaced them, changed the hydraulic filters, dumped what fluid I could a couple of times topping it up in between, and then went to try it out again. To my shock, the machine did exactly the same thing, no real power. Same symptoms as before. Now I had to walk away from it for awhile since I was ready to lose my mind. I truthfully don't know what to do next. I'd like to rule a few things out before being forced to bring this thing to an expert. Other observations: - when I had the cylinders removed, I started the machine and fluid began spraying out of one of the disconnected hoses immediately so I shut down the machine. This surprised me because I was under the impression that if the sticks aren't being moved, then the valves should be shut to the cylinders and no fluid moving. Am I wrong about this? Or do I have an issue within the valve body itself? If so, then why would it affect more than one function? Doesn't seem right. - when the cylinder stops moving, there's no noise of anything bottoming out, or the engine laboring. Seems odd like a relief valve is bypassing fluid somewhere. I may be off on this as well. - one wierd thing, when I'm trying to move the boom after its stopped moving against the ground, and I bump on of the bucket control functions for just a second, the boom cylinder seems to gain power and move a little. It's almost like a spike in hydraulic pressure for just a second. Very strange, and makes me wonder about this priorty valve I've been reading a little about. It's really hard to get much information on this machine for some reason, and looks like I'm getting my education the hard way. So.....sorry for the lengthy post, and great thanks in advance to any advice you can give me on trying to get this old gal up and working again. I really appreciate it.
I should correct something, when I said I "bump on the bucket control functions" I should have said, the front end bucket and boom on the front of the machine.....sorry.
Welcome to HEF firedawg. :drinkup I can't really help you with specific information as I have no experience with the Deere 410C specifically, and limited knowledge of Deere hydraulics in general. However, the oil you mention coming out of an open cylinder line when you started the engine, this is normal if the control valve has anti cavitation valves in it, which very likely it does. Nothing unusual there. As for the priority valve, typically speaking, that valve comes into play when driving the machine and using the loader, such as when you load the bucket then start driving while raising the bucket to dump the load in a dump truck. The idea of the priority valve is to give steering priority in this situation over lifting the loader arms. But again, that's generally speaking. And with most Deere hydraulic systems, they use a closed center load sensing system with a variable displacement pump. The pump "senses" the demand of oil required to operate a function and reacts by delivering that amount of oil, whether it's just a little or full tilt, it always try to provide the amount of oil demanded by functions being operated. I know this doesn't say anything that helps with your problem, but it might explain why you don't hear the engine labor when a cylinder hits full stroke, since the cylinder is no longer moving the pump senses it doesn't need to deliver oil to that cylinder, the pump simply "destrokes" to standby pressure. What is curious, you stated if you operate the bucket control while operating the boom control the boom gains a little power. That sounds like the pump is fit and able, able to deliver the demand, I just don't know enough about the machine circuit to understand why it does this. Hopefully someone else will offer some more info.
Thanks Willie, what you say makes sense, truthfully, I'm trying to grasp how this system really works. The bumping of the front controls really has me scratching my head. It's only for a second, but it definately provides some sort of bump to the back end. It's as if it forces the pump to move some fluid, and when the front end valve is released, a pressure spike moves the cylinder on the back end. Very odd. At this point I'm just wondering what to test or check next. I wish I had a manual of some sort to help figure this out. Thanks for your reply!!
Yes, at least that's what your info indicates, when you bump the loader it increases power to the digger, if only for a moment. That indicates the pump is sensing a demand and responds as it should. But don't get hung up on that, it only indicates the pump is able to deliver, doesn't mean it's delivering properly, it only means your pump isn't trashed internally requiring replacement, but there's something in the sensory circuit that's still awry, I just don't know what to advise on that machine.
I don't see any problem here. What are you comparing it to for power? just expecting it to have more power? I'll take Willie's word about the hose spraying fluid, shouldn't matter anyway. Everything else he said applies completely to this Deere system. There is no sensing circuit like more complicated systems, the destroke valve is in the pump, you can cap the output line from the pump and it won't know the difference. The priority valve cuts off flow to the loader, the hoe is not affected. I would think the stabilizers should lift all the way up, maybe if the cleats dig into hard ground they won't? The stick (technical name for the smaller boom) should definitely move the machine, but you said you had 2,700 PSI, so??? Try to fill the bucket by scraping 4" of topsoil with the bucket teeth pointing into the ground at a low angle. The bucket should fill easily. Have you tried to lift anything with the hoe? a full bucket with boom and stick fully extended is a lot of lifting force. How does the loader power feel? Did you check the old filters for junk? Did you clean the suction screen (if there is one?) that shouldn't affect the power but it's always worth doing when you drain the fluid.
Thanks Delmer for your response, yes I do have the 2700psi, however, am unable to dig with the machine. That's the part that really doesn't make any sense to me, you'd figure that if the pressure is there, that it would work perfectly. It simply doesn't have the power to dig as it should. I understand that everyone wants more power, but this machine just isn't doing what it should compared to other machines. Now admittingly I'm no expert but from what I understand the 410 should have enough power to rip the ground fairly easily. One of the mechanics at the John Deere dealership was kind enough to give the machine a try when I drove it over to pick up the hydraulic filters, and it had him scratching his head as to why there was such a lack of power. He explained that it could be a variety of reasons and suggested that I begin by testing pressures on the machine to track it down somehow. I took his advise and ended up having the cylinders rebuilt due to the pressure making its way to the cylinders. I did change both filters and the ones that were removed were both dark but not full of anything that I could see on the outside of the screen. The filter for the reverser was surprisingly unplugged evern though some material came out of the drain when I dropped the oil, it was a definately noticable amount of something. As for the pick up screen, I didn't check that because to be honest, I just didn't know about it. I'm assuming its behind the large line coming out of the transmission which looks like it feeds the main pump along the right side of the tractor. Now you've got me wondering what other things I can safely remove and check for gunk or debris. Anything on the pump or valve bodies I can unbolt/unscrew to check O-rings or seats that may have something blocking or making them stick? Thanks again Delmer for your response, I'm going to try and hook up the guage again and double check my pressures, that part simply has me scratching my head.
firedawg, It may be a good idea to let an experienced backhoe operator try out your machine. The mechanic might not have been the right guy. No backhoe is strong enough to dig into solid ground without combining functions so that the bucket is traveling in a horizontal plane towards the operator. If it's hard packed parking lot material you will only be able to scrape the top. Practice this movement a few inches above the ground and then try it 3 or 4 inches below the top of the soil like Delmer says. You need to be pulling on both sticks at the same time. Or you can go find some realy soft mud and fill your bucket to see if you can lift it with the boom extended.
How about a restricted return line from the hoe? When you're completely stumped think "little red plastic plug" Many parts aren't that hard to remove, just don't let the springs fly out of there. The destroke valve in the main pump would be the next place to look after checking return pressure at the hoe valve.
Thanks again gentlemen, I had a chance to do some of the service on the machine today ie. change out hydraulic fluid again and engine oil/fuel filter. I also had to change a leaking pressure line, and suction line to the pump. By the time I was finished I didn't have enough time to recheck pressures. I did however run the machine, and my friends old machine that is also sitting there (he's kindly letting me use his shop to work on my unit). His machine is an old 75ish case backhoe, gasoline powered, and it handily outdigs the 410 when the two are compared side by each. One thing I definately did notice today was that I'm unable to perform two functions on the hoe at the same time. If I'm drawing back the dipper, I'm unable to raise the main boom at the same time. At least not at full function, if I'm moving each very slowly they'll both operate but not particularly well. It seems that each one is fighting over available pressure or fluid. Again, scratching my head, this isn't normal is it? Delmer, when you say return pressure, do you mean the pressure arriving at each cylinder, or from the valve body to the......pump? Also, I've checked the destroke valve by tapping power to it, and I can hear it moving. Should I remove it? If so, what am I looking for in there? Sorry for all the (uninformed) questions, but I do appreciate the helpful comments.
With the engine at 2,000 rpm, warmed up oil, extend the backhoe all the way out with the bucket sticking out, then time it while retracting the boom and stick and curling the bucket. The boom has a cushion so it doesn't hit the end of the stroke hard, it slows down about 30 degrees before the end, stop the boom once it slows down at that point. The spec for a different C is 12 seconds max, if your problems are as bad as they sound then I'd bet it will be more like 30 seconds. As far as the pressure, there's just no way you can have everything you've said, something's got to give. How about hooking up the gauge to the main pump and see what the pressure is when the hoe is stalled, say dug in and the stick is stopped. My theory about the return pressure from the hoe valve body to the pump is extremely weak, a blockage could easily slow the hoe functions down, but the power would still be there, just slow. Can you see any obvious places that are cleaner than they should be, or fittings that have paint scraped off, like somebody has messed with? The destroke solenoid and the "stroke control valve" are both suspects, but that would show up in low pressure, so might as well retest that under load first.
Thanks Delmer, I'll give that a try. The functions of the booms and bucket move quickly without load. I believe I have a spec sheet for the stroke/movement times but haven't bothered to time them as they very responsive but I will, along with keeping the test guage on the pump. Luckily I had them make me a 12' line for the guage so that I can view it from the cab continuosly. I am curious about the fact that I'm unable to move two booms at the same time though......any thoughts? I really wish I had a way to view the flow from the pump itself. At any rate, I'll retest my pump pressure under operation and time the movement of the booms.
I found some info on the 410 buried in my work computer today. According to the theory of operation, the priority circuits are steering, backhoe, outriggers, and auxiliary functions, front loader function is non-priority circuit. All that means is the priority valve provides oil to the priority functions first. If their operations are satisfied, the spool in the priority valve shifts and delivers oil to the loader function. If pressure were to drop in the priority circuits while operating the loader, such as when you turn the steering wheel at the same time (meaning it's requiring oil to steer, the priority valve would sense this "demand" at the steering circuit then shift the spool to restrict oil to the loader so you could steer. Same would apply to the backhoe, it should get priority over the loader. This makes it curious that you can improve the power of the backhoe by operating the loader control. During backhoe operation, the loader circuit should be pretty much blocked off by the priority valve. In theory the loader control should have no effect on the backhoe when backhoe functions are being operated. I don't know how things connect to the priority valve, whether it's hard pipe or hoses. If it's hoses, I wonder if someone has made some crossed connections? Another thing you could try if the connections to the priority valve are hose connections, disconnect the loader circuit as it leaves the priority valve and plug/cap that circuit. Do the same for the steering circuit, disconnect and plug/cap it. Now see how the backhoe works.
If the cycle times or speed seem fine then that's your flow. The power comes from the pressure, which tested fine also?????? The flow at pressure is power, which is obviously low. Yes, you should be able to use all the hoe functions at the same time, it will slow down, but never stop... You're usually using three functions at the same time when digging. The system relief valve isn't supposed to operate just from stalling a function, and if it was leaking I'd think you would hear the engine load, and possibly some whine or squeal from the valve, but it's near the engine so maybe not. The priority valve isn't the first thing that gets washed so you should be able to tell pretty easy if somebody has messed with it anytime recently.
Thanks Willie, those are interesting thoughts, and a good explanation of the priority valve. I'll have to see if I can source the proper sized plugs for the valve. I pressure washed and degreased pretty much everything I could reach quite thouroghly so I could see what's going on under the machine and not end up an oily mess. From being under there today I seem to recall seeing hoses to the priority valve but I'll have to double check. All the lines look very original and untinkered with, but that's not a "for sure". Something is clearly off. I've got pressure, according to the unloaded movement I've got volume, so I'm thinking do I still have pressure and volume under load? Delmer's on the right track I think about testing my pressure under load or multiple cylinder movement. I'll try that and see what happens, I'm very curious now. As for the bumping of the front controls for a boost of power, I'm stumped, all I can think of is that it causes a flow of fluid, and when that flow stops suddenly, it may create a sort of "water hammer" in the direction of the hoe giving it a quick boost. Just a guess. And as for the loss of function when preforming multiple functions, that makes me think that there isn't enough flow to keep everything "happy". Geeze, hopefully some pump pressure testing will tell me more of the story of what's going on. Hopefully it's just not the pump not being able to keep up when things are moving. Is there a pressure relief valve of any kind in the valving for the hoe? Could there be some crap caught in there mucking things up? One thing I did notice today while changing the hydraulic oil was a small say 1/4' piece of curled rubber in my 5gal pail, now I'm not completely sure it came from the hoe, but I believe that it did. It was large enough not to pass the pickup screen but I'm wondering if a hose somewhere in the system, or something, is delaminating. That could be impossible to track down but are there ports I can check to see if things are clean anywhere without opening a ratsnest? Sorry, just thinking out loud here. No chance of some air lock from changing the cylinders and fluid is there? I didn't think that was possible in this system, maybe I'm wrong. Again guys, thanks for your expertise and help on this one.
Give us a pic of the curled rubber. How does the loader operate? significantly more powerful than the hoe? The water hammer affect from the bumping the loader points clearly to the destoke or stroke control valve. On the other hand, a partial blockage in the return line from the hoe could cause any one function to lose power, and then plug completely with more flow from two functions. And then unblock for a second when the pressure drops from the loader operation. That shouldn't be hard to diagnose, there's only one big hose from the hoe valve back to the filter (probably the filter?), that hose should be somewhat flexible all the time, if it's pressurized it will be very stiff. Don't touch it even with a gloved hand, poking it with a stick from a safe distance, even hooking a piece of wire around for an improvised pressure gauge should tell you the story. The only system relief is in the priority valve, the backhoe valves have relief valves for the individual circuits, not likely the problem here.
Geeze, I didn't keep the piece, poured it out with the oil. I'm curious what you mean about not touching the return line. Is it hot? I'll have some time this afternoon to hopefully hook up my gauge to the pump and view some live pressures. I'll crawl under the machine and see about how though it is to access the hose you're talking about. If I can remove /inspect/and put it back easily, I'll give it a shot. I've only got limited time today since I've got my young daughter until mom comes home after lunch, and then I've got to work this evenings night shift. I'll let you know how far I get and what I manage to find
Was the piece an o ring, or from the inside of a hose, or ??? Never look for a leak with your hand, oil injection requires surgical removal, and apparently doctors have never heard of this so by the time they figure it out amputation is more likely. Inspecting a suspect hose is dangerous enough in my book. Of course you can examine it when it's not running, but if it's holding pressure when the hoe is stalled it should be easy to tell that it's stiff. That might, or might not drain all the fluid if you remove the hose, be prepared.
Well, I managed to get a couple of hours fiddling with the machine today. I began by hooking up my pressure guage and running it into the cab so I could observe it. Pressure at idle @2700-2800psi. I then began to time the movement of the booms. RPM was set at 2000 Front main boom up 3.5 sec, down 2.5 Main hoe boom up 2 sec, down 2 sec on level ground. Dipper in 3.2 sec, out 2 sec Bucket in 2.4 sec, out 1.8 The pump pressure remained stable during all operations with the exception of lowering the main hoe boom to the ground, in which case it dropped to 0 psi. This doesn't surprise me as I figure the wieght of the whole assembly wants to go to the ground anyways and is probably creating a near vacum with the piston within the cylinder. Oddly enough, I was able to preform dual function movements after this test with no big dropps in pressure. This was not the case the other day before I flushed the hydraulic fluid. So, I drove it over to the field and tried to do some digging. And, for whatever reason, it decided to dig like a champ!!! I have no explanation for any of this. None. I am by no means upset by it though. The only thing I can figure, is that perhaps that chunk of rubber did in fact come from the machine, it wasn't an O-ring but if it was, it was a very thick one, so I don't think so. Very happy I may have a bad hose somewhere that I'm going to have to try and find, or I may have already replaced them, as I changed two of them during my fluid service. One thing though, during testing the boom times, there was no slowing down of the booms as they began to reach thier limit. It was actually a little unsettling due to the fact that it's alot of steel coming at you before it does in fact stop, and also its a pretty violent thing when it happens. I have no intention of running the machine this way, but to do the test.....it was what it was. Is there any way to solve this? If so, where should I start looking? In addition, Thanks guys......really, you have no idea how much I appreciate the help and advise. I'm new to hydraulics, and without someone to talk to about it, I was feeling pretty hopeless. I'm very grateful. And also very grateful that I got so lucky as to have regular servicing of the machine accidentally solve the issue. But I'm still curious where that chunk had itself stuck to cause such strange problems.
Does anyone have an idea what should slow the booms when they come close to thier limit on this machine?
Well, I've never had one of the cylinders apart on one of those machines, but it's not unusual, actually typical, to find cylinders on excavators and backhoes to be machined in such a way that it provides a restriction on the cylinder piston as it nears the end of the stroke thereby doing away with the impact shock of the piston bottoming out in the cylinder.