Hey guys, on my hitachi ex120-2 still has slow/weak hydraulics. Got a new solenoid valve but might have ordered the wrong one because the new one doesn’t have the adjusting bolt. And it requires a smaller pin (which didn’t come with it) and the hole is much smaller. Question can I use this valve if I make a pin?Does anyone know what size the pin is?
Which solenoid valve? Are you talking about the solenoids on top of the pumps? Post a picture of the old solenoid and new solenoid. If you are talking about the DP sensor, then the new one's are not adjustable.
The proportional solenoid valve. Just wondering if I can use the new one. If I can, what do I do about the pin. The old pin is too big.
I don't have an answer for you. I have always replaced the solenoid coil on top of the pumps with the cast valve it is attached to as an assembly (first picture). If it is from the solenoid valve block like the second picture then again I don't have an answer. LAUCHAU would be the guy to contact for that answer.
Thanks mg2361, it the 2nd picture. How do I find this Lauchau ?
Top left of the forum page is a drop down titled members. Go in there and search LAUCHAU and when his username comes up click on it. Then you can see there will be a link to start a conversation. Start the conversation and ask him your question.
tried that he’s not listed.
He comes up when I search, interesting. Try this thread and click on his name. HeavyEquipmentForums When you click on his name you will get this
Got it thanks. Spelt it wrong the first time
Thanks for your believe. They are different then they can not be interchangeable!! One is solenoid valve (don't have adjusting bolt) and the other is Proportional solenoid valve.
and they are also different the some parts!!
I don't believe they will interchange. Different setup.
Ok thank you
You mentioned slow/weak hydraulics. All functions or one function? Did you try swapping the two solenoid valve assemblies on top of your hydraulic pump to see if your condition changes? Also make sure your fuses are good, especially the controller 1 A fuse.
the 1 controller fuse was blowing so I replaced both valves on top of pump. Fuse no longer blows but no change. Don’t think all functions are slow/weak but travel and swing are real bad.
I am trying to get to the bottom of similar issues, new to this forum, has anyone actually solved this? It seems like the conversion kit isn't the right answer and I haven't seen a solution in all my reading yet.... I bought my 120-3 a few years ago and it ran perfect for a while but all the same hydraulic problems as everyone else.... Weak hydraulic functions, a load on the hydraulics when I start it , excess vibration, dead heading (stalling) been dumping money in this problem for too long now I'd love to get to the bottom of it..... thanks nate
Hi Nate. This post only started on Saturday so just follow along to see if it lands on a resolution. I know you have a post started so we'll try to keep going on your thread to keep the two machines separate.
Has pilot pressure been checked to eliminate that as a cause for slow hydraulics? Do you have a service manual? Did you check the adjustment for the DP sensor and the pump angle sensor? Did you try and get the blink codes from the controller?
. Don’t know how to check pilot pressure but main pump pressure has been checked. DP sensor has been checked and angle sensor has been changed replaced. Someone told me little Dot on angle sensor is supposed to point away from the label on the sensor. Manual says opposite.
But there is still a voltage adjustment that has to be made to the angle sensor to insure the information getting back to the controller is accurate.
Yes Nate appears conversion kit does not work. Think we’re both in the same boat. . Don’t know what link codes are
I hate to say this but I believe that the biggest problem with the Hitachi dash 2 machines are people who know very little about them are trying to fix them. They were Hitachi's first venture into a computerized machine and they had some issues. But if you have the diagnostic computer, either DR EX or DR ZX, what ever version, generally speaking a good troubleshooting mechanic can figure them out. But you have to understand them and you have to be there at the machine, guys like mg2361, lachua and a few others can offer good advice but without being there it's nearly impossible to get them up and running. And throwing parts at them without knowing how to properly install and adjust them does nothing but cost a lot of money with no good results.
I really wish I had that option but on my 120-3 being a grey market machine I can't find anyone willing or able to do these diagnostics.... even dealerships ...I never hesitate to pay a pro to do something like this but I absolutely cannot find one in Maryland.....any suggestions?
That is totally crazy and should not be a problem, it's the same exact machine as a 490E Deere. While Hitachi had a 120-2 and -3 machine Deere had the early and late serial number 490E, only difference between Deere & Hitachi is Deere used their own engine. Maybe you'll have to paint it Deere colors and just call it a 490E, are there no independent mechanics in the area to look at it?
I wasn’t blaming anybody About A sensor I just wanted to make sure I was doing it right. Considering I was told by a professional the opposite of what it says in the manual. I put the sensor on with little dot facing away from the label and The highest reading I could get was 4.1 I didn’t just jump on his excavator and try to fix it like an idiot. I’ve had five so-called professionals work on this thing one from the highest rated company around came out looked at the thing for 45 minutes and said he couldn’t figure it out.because it’s a gray market machine. But I received a bill for $800. Last guy came out and did some stuff and now won’t return my calls. I believe I’ve made more improvements than any of them.
I agree its crazy but the local john deere dealer said they could do it and the tech came out couldn't figure out where to plug it in and told me if there wasn't any check engine lights on he couldn't read anything any way.... charged me 600 for the trip regardless just to come out and provide no answers. The hitachi dealer won't even touch it, they curl their nose up and say it's a gray market machine and basically cannot help me at all. They turned me on to a mechanic who was supposed to be able to help. He came out and toyed around a few times no luck.... Over the last two years I've spend over 5 grand on guys who are supposed to be the guys that know what they are doing... my guy whos working on it now is a little more old school fixing things doesn't depend on the computer plug in so much but it would be nice to be able to run a diagnostic thats for sure
Just an FYI for anybody out there. The dot on the angle sensor needs to be opposite the wire harness of the sensor. The little spring clip that sits on the "A" sensor shaft that fits into the slot inside the pump needs to be tight (should be replaced anytime the "A" sensor is replaced). Also when the sensor is out put a screwdriver into the slot of the pump and try and turn it back and forth. If it turns more than a few degrees then there is wear inside the pump in the feedback linkage. "Some issues" is an understatement. Yes, I agree with excavator that these machines are extremely complicated considering their vintage. And yes trying to troubleshoot from the seat of our pants can be almost impossible at times. Like excavator, I believe if I'm not there to touch, feel, see, taste, smell and hear the machine, then troubleshooting with an individual who does not understand the inner workings of these machines can be frustrating at best. Anybody wanting to work on their own machines should not even consider touching them without purchasing a tech manual. Diagnostic software would be highly recommended also because it can speed up the troubleshooting process as well. I would personally recommend buying a Deere 490E Operation and Test manual for the EX120-2, -3 Hitachi's because they are easier to use and understand than the Hitachi manual. For those of you that have had negative experiences with dealers or other professionals will need to be patient with our recommendations because like mentioned earlier we are not there. I myself will try to throw out some simple things to do on these machines to help narrow down issues without having expertise or special tools, even though that is not the way I would approach troubleshooting that particular machine. Sorry, venting
Thank for your mentions. Anyway, I think model EX of HITACHI is too familiar. we have used the tools just for ZX... series
...and almost engine install on HITACHI machine are ISUZU. You should use the IDSS tool for diagnostic.
Isuzu in the -2&3 machines are not electronic engines so no diagnostic software needed.
Not sure why when I added to mg2361s post it doesn't show up as added but I'll repeat here. Some of the early Hitachi books had the wrong info for installing the A sensor, they showed the dot towards the harness. And I agree, I use the Deere manuals far more than the Hitachi's on these machines. We also have to remember that these machines are close to 30 years old, that's 30 years of heat and oil and often bad mechanics working on them. I've found that most issues are caused by bad wiring harnesses, usually the harness end where it plugs into a sensor or valve ect. The harness ends are available from Deere.
Agree with your opinions. Regarding to Technical Manual, I never have used the J.Deere manual so I have no idea!! but I have a feeling that HITACHI's documentation is easy to understand also. I attached file for your reference. https://www.mediafire.com/file/o8dxek1yvr4h5tm/EX120-3_T135E-00_Technical_Manual.pdf/file
Exactly. HITACHI manual said like that. Unfortunately, the "A" sensor part made in China usually is not like that!!!
Back to Mike's issue. Mike, the easiest thing to do is Tee into one of the pilot lines that go to the pilot caps (that stroke the spools) on top of your control valve. Fully activate that function you are Tee'd into and read the pressure. Post the results. Should be in the neighborhood of 700 psi.
Very simple way to check. You should try to pull-out 02 connector of SWING PSV and TRAVEL PSV. After disconnection of 02 PSV, the SWING and TRAVEL will be faster than as it was.
Thank Lachau I’ll try that. What will that tell me. Bad solenoid? And what if they don’t get faster.
That means the controlling of PSV is out of order! You should check the wires, connectors, PVC controller... You should check the VARIABLE PRESSURE COMPENSATED VALVE which install in front of main control valve. They might be stuck at closed status!!
For more detail.
Thanks Lachau, that’s some good things to check. Hope I can get on it today but still need to replace the psv I removed. Which was stuck. And I noticed someone had installed a nonadjustable psv. In the swing parking Spot. Which I ordered and should receive soon.
Hay lachau, I tried disconnecting the 2 psv like you said and nothing changed. Swing and travel still slow/weak. Actually Travel forward and backward it’s OK but track steering is very very weak. You mentioned checking vpcv. I’m assuming I need to put a gauge at the port. Do you know how much pressure it should read. Thanks for your help. Mike
Please see Group 6 (Operational Performance Standard) of Section 6 (Operational Performance Test).... page T06-06-05.
Thanks again
Gday LACHAU,looks the same to me but would that manual be the same for ex200-3 ? If not would you have the same for the ex200-3I have some issues with my machine,your help would be appreciated. Cheers James
Sorry!! Can you explain in more detail what you want to talk about. What is EX200-3I?? I have never heard of Hitachi excavator model EX200-3I!!!
Gday LACHAU,sorry about that,was just a typo i didn't put a space in there, the machine is just your average hitachi ex200-3 that is here in Australia, I was looking at the service manual you posted and just wondering if it's the same as my machine or maybe you have one you could share with me for the ex 200-3,hey thanks for the reply much appreciated. Cheers James
Here you are. Good Luck. https://www.mediafire.com/file/nsrufuy2ty0zzom/EX200-3+Technical+&+Workshop+Manual.pdf/file
Thank you LACHAU that will be of great help... Cheers James
Gday LACHAU, You're post here and on this forum is very helpful, the machine is working ok,although travel is slow and jerky I did as you mentioned and unplugged the travel PSV,made a big difference travelling smooth and fast,i haven't tried to check wiring as I am still unsure how to with a multimeter, have attached a picture of pvc could you please take a look and reply your thoughts,or if anyone else has seen this before.any input appreciated. Cheers James