Hey guys. I borrowed a neighbors Deere 26d excavator to do some cleanup of underbrush growth. Worked great until one of the final drive motors started making a slight clicking noise then all of a sudden I lost function with the dipper stick. Shut the machine off and let it cool down some. Started it back up hydraulics worked good for a few minutes and then the dipper stick got real slow to non functioning. Shut machine down for a hour or so. Started it up again, hydraulics worked great. Ran it for maybe 30 minutes and these functions stopped working main boom, dipper stick and bucket roll. Hydraulic thumb, dozer blade and the other track work just fine. Figured out the recommend hydraulic oil wasn’t in the machine. I drained the tank and installed a new return filter. Didn’t see but just very few particles in the oil I drained out. Filled it back up with the hitachi super ex 41 oil at $137 a 5 gallon bucket. Required two buckets. can anyone point me in the right direction on this. I have no experience with these pilot control machines and have no idea where to start. Thanks for any assistance!
The left rear corner just below and in front of the hydraulic pumps is a pilot filter. Remove it and inspect for debris.
Yes sir I’ll look for that and give it a try. Thank you
YIKES!! Was the bucket handle made of gold?
You would think so. This stuff is crazy high! A bucket of hy-guard at my local jd dealership is roughly $72 so this Hitachi oil is about double that price. I asked the shop Forman if the hy-guard oil would interchange. He looked on the computer and said it would not. That’s all I had to go by.
It should have 2 pumps sounds like the pump that runs the one track and the stick is bad there should be a case drain filter on it pull it and look foe pieces parts
I’m not sure. I’ve only found the one pump that’s basically under the operator station on the left hand side. I’ll look again when I get home from work.
it will be one unit with 2 pumps in it it should have 2 high pressure lines coming off to the main control valve
Ok thanks! I’ll look when I get home from work
Ok so I fiund the pilot filter. There is some very small brass powder flakes in it. There are no bigger flakes or any chunks in there is this indication of pump failure? I plan to change the filter any way just in case it will make a difference dealership was closed before I got home. ]]
That's not good. The piston slippers on the main pump as well as the drive motors are the only places that brass would be coming from. Also that brass floating in the system can cause things to stick which could be giving you your intermittent functions. Do you still have the old filter that you could cut open? Remove the hydraulic filter and drain the reservoir. Is there brass on the bottom of the reservoir? It is technically one pump with one rotating group that has the rotating group using half the pistons as one pump and the other half of the pistons as a second pump.
That is a lot of brass you have a failure did you pull the case drain filter and look at it
I do have the return filter I pulled from the main tank I can cut open. The pilot filter is still in there and can cut it open when I swap it out also. I just wasn’t sure if this amount would be considered fairly normal or not. In the past when we have changed hydraulic filters in our mill, I have seen brass like this and our system is still operating normal. Also I’m not sure about a case drain filter? So far I only know of the return filter in the tank, the pilot filter under the main pump and a suction screen inside the tank. Is there another filter also?
Also if I have to drain this tank again, I’m thinking about running this new oil through our filter cart here at work to clean the oil instead of buy another $300 worth of oil. It has two 3 micron filters on it and believe that this machine has 10 micron filters.
It don't look like it has a case drain filter
All this, on a borrowed machine? That's rough. It looks like MG2361 has you on task. In a system with gear pumps and actuated cylinders, a little brass ain't the end of the world. With a piston pump and motors, there is no amount of brass that is acceptable. It almost always goes back to a broken or missing piston slipper. Bad news.
yeah that’s just my luck I guess. I understand what y’all are saying about the brass is there a way I can tell for sure the pump is bad before I have to shell out 2 grand? It’s looking like replacing the pump AND the left final drive.
Unfortunately, no. Disassembly and verification is the only path. The bad thing is, case drain is shared between the pump, travels and swing. In theory, all 3 plus the turning joint are full of trash.
Man!! y’all aren’t giving me any good news. when you say disassemble and verification, you are talking about disassembling the whole pump? There isn’t any kind of pressure test I can do on it to verify it’s weak?
Thats a question for MG2361. I don't know where the test ports are. Yes, you can test to prove or disprove. But to see the level of contamination, inspection is the only way. Bits of brass missed, migrate and cause more bits of brass.
Yes there are pressure and flow tests that could be performed. The problem is that your pump might test good and the problem could be in the motor so pressure and flow tests would pass. With that much brass floating around there is a slipper issue. If it started in the pump then it is in the motors too and vice versa. So regardless of where it started both the pumps and motors would have to come apart to be clean/repaired/or replaced. Just because you borrowed the machine doesn't mean it's your fault this happened. It was going to happen no matter what. So don't feel you are obligated to fix it. It is the owner's responsibility.
Yes sir I see what your saying. I guess what I was hoping was since the final drive motor went out and someone said on a previous post that the brass could be from a drive motor and/or the hydraulic pump, that the brass could be from that motor and the pump was actually good and maybe the hydraulic problem was from a bad pilot control valve or a stuck open relief valve. That was my train of thought on asking about running pressure test on main pump.
Also what I’m trying to wrap my head around is this. why has the dipper stick and bucket functions stopped completely? Main boom fiction is slow but works. Swing works blade up/down and right track all function great. sorry for all the questions but I’m just trying to figure out how this all works
One pump lost its control. It's no longer getting a signal from the MCV. The blade typically works on a gear pump of its own. So gear pump don't care. Are you running backhoe control or ISO? Does it have a pattern change valve? Man, i hope the valve is stuck in the middle.
It’s in the backhoe configuration. What would this pattern change valve look like? This is the first track hoe I’ve ever ran. I have a old John Deere 310a that’s been down for awhile. I thought it was odd it is setup like a backhoe because I’ve always been told trackhoes operate opposite of backhoes.
That's a question for MG2361. If it has one and where it is, he would be able to tell you. Right track says to me one side of the pump is lacking a signal or is hurt. How is bucket function?
Ok did a quick google search and found where it is. Went out there and swapped it iso. Now the dipper stick works slow and the main boom doesn’t work since they are reversed now.
Then, you're gonna have to determine if it's a lack of signal or hurt pump.
All this on a borrowed machine that was filled with the wrong hydro fluid? By the way...I think this machine needs zinc free fluid (that’s why the price is so high for hitachi super ex)... running with the wrong fluid damages parts internally?! Takeaway:: This is not your fix to perform!
Yes sir. I don’t feel like it’s anything I did that caused this but it did happen while I was using it. So I’m hoping we will be able to work something out.
Do you know what hydro fluid he used? I have a similar machine and unless you use the hitachi super ex it WILL damage parts in the pump. Maybe time to hire a mobile mech who can come out and confirm the damage is not your fault? Sounds like you’ve already put a fair amount of $ towards the problem... being on good terms with your neighbors is important but not when it’s negatively affecting your checkbook for something that’s 100% their fault!
I tinkered around with this thing a little bit today and I stumbled onto something I can’t quite figure. As I stated in the original post the dipper stick and bucket fictions stoped working completely. Today I was messing around and had the left track lever pulled back just enough to actuate the reverse alarm, so when I pushed the lever for the main boom down it picked the trackhoe up which it would not do before, so I pushed the dipper stick lever and it started moving and the bucket curl function returned also. So then I moved the track lever back up to disengage the reverse alarm and all the functions returned to this Main boom: no power to pick tractor up Dipper stick: no fuction Bucket curl: no fuction So when I move the left track lever back just a little again to engage reverse alarm, all the functions started working again but they are really slow. Anybody explain what’s going on here to me please??
Because when you engage the track it kicks the other pump in either you have one section of the pump bad or the half section is not getting siginal to up stroke
Ahh I see. Thank you!