Hitachi ex 120-3 hydraulic issues

natemarine · Apr 23, 2020

ll be honest, from the symptoms I'm starting to think I had one bad solenoid at first. Then I had a muffler problem that was causing over heating. The temp got up high a few times but when the buzzer came on I always shut down operation to let it cool. Im thinking during this time the other solenoid may have started to malfunction as well. Is it possible to have two of them malfunctioning?

Also I have to ask, why are the aftermarket replacement parts no good? Dealership wants way way too much money for original parts. After all this isn't an american hitachi. The part numbers matched.... everything seemed exactly the same. Is there any particular reason they won't work? Besides the dealerships upcharging their brand names for a ridiculous profit, is there really a difference?

natemarine · Apr 23, 2020

mg2361 said:
Then maybe the wrong solenoid was replaced?

we tried many combinations with the new solenoid changing location and then switching wires back and forth. No matter what combination we used we either got slow functions with no load on hydraulics, everything sounded right and normal for once. When switched the functions turn fast and jerky, and the load on the hydraulics returns. The fast and jerky didn't start until we installed the new solenoid, it definately caused a change. So i am assuming the one we replaced was bad and it seems like the other may still be messed up, another aftermarket on the way....

natemarine · Apr 23, 2020

rgl726 said:
Did you replace all the parts with the original hitachi parts? Specialy the pump solenoids? Did you set the angle sensor correctly? China made parts wont solve the problem on electrical side.

This machine is very complicated and fragile to handle.

Did you check also the pilot pump pressure reading?

Is the pvc computer working properly?

Did you check the wiring continuity for all the sensors and solenoids?

natemarine · Apr 23, 2020

mg2361 said:
Then maybe the wrong solenoid was replaced?

I'm hearing mixed reviews.... is there a problem with after market parts? Dealership wants way too much money for them, what is the difference? the dealer said its the same but it affects warranties, I dont have a warranty lol.
pilot pressure pump was just replaced I'm assuming the pressure is good. Have checked all the wiring and harnesses for frayed wires or wear but not for continuity. It has been a problem to get shop manuals and specs because it is gray market machine. I just found a guy with the john deere 490 e program on his computer but I'm thinking about ordering dr. zx (mine is ex)

Did not adjust angle sensor tried to put it in exact position as the other (do this by ear? using laptop? please advise...)

Both computers (on top of eachother behind seat) had flashing red lights when I checked

beyond this I don't know if pvc is functioning properly

I have tried to hired heavy equipment repair companies to fix it but they can't ever figure it out

dieseldog5.9 · Apr 23, 2020

My Experience with aftermarked sensors can be summed up by this box, notice the shiny DP Sensors, and the shiny angle sensors, all junk the problem is you will chase your tail after you put a new after market sensor in. I believe the new DP sensor is $1000 from Deere.

gCBok3mO7OGwSK9sVSMSN4hammO1ieHkr9O86K5vBm7xWDydbevq2Ar0JwHbYK80HNbsGm7KFz0R-zJFkd2jTymIhqysMNU2CHJo9N8wgLB4aiFEq7QWf_L8JmO9sSOncpF9opIqDfZvw-ATcCfTE4Je2sV8k5adlPdRBoknoOdGh1qhBOdvRytQH-BsoSxcbPpLm5bpC3ow9cV1Pq5YwuyHfPv6qJDAkuZ7MqKpnYKnDMV_UIS5OFNi5ThMwX6NsKGCi43Pd_s39XzmAnGIkVgsXK4b-ztvH_MVXteiPwbG_6FC90zMfnG_FilkjvdzLXNR0X-O34KvpUjIzUFeR_jHjWTYnhzudsWLHSAAjlHJ38AkqOkFARVw2xMc-avtf5mTCp-BNqqXwMw9rZbo_DiJUSEDtLAJl9fbNPkg4JBFl8gzZ8mGMB1WJ-RHzFUuYfsKXU9hD2J1PXvrYJA_tVsba4jznIcilR0TEHn3_e2aq3v3mSApVGfNCKkmxLNs_1oU7YNtt-h-fpptpU8vEMTY8fqGjLko2IOWpgZR5lsW5pSqwDFDh9DyX797h0QjywHtPTVXhMKc1mj6rpj0PUYcjJXWq7xFF4k7Xkr9UVxU70Vh3GgCEJEde6okKNLrCQHPEF_i6lWU3w__J51CYD4hvVNZe-TpFmDYczvloaVgP3_H7D55s_iTUlyE=w708-h943-no

Setting the Angle Sensor take a special harness

xC37F4T1ELF1o75CZvN3ZzN2iyv3XUkNonbLF5OPv5VsyZ88SNIUJhcGvJnhkS3fIiMfFx8HK19rroZJ_N_ddPXCpKnLTw-M5a0RS_Uq9n1EkfAgtDZ7x4-1yv7KaxK7xTWSnDxMyk2777acQtBlybCCWNXKF4FwYdJb-Z32myZEbYZdWv0v3gEHfv3H5xv8g2QlgzYmmZ7NyviD7DP4rVebjxTdwFM6k1TzGEI5ljF3ma0MprQ1Uh_NvdYTvpy5bEu6hTYguvYKqUWwNCEPX0FJ7rMnnDFINMkt8XR4zvG6ciAheXh58VwmEf6HbT_Eiyc4bieoKRz-fl0xt99jZimmQcXt3J42Ie9dGjbAz_3NvflS13TPMAfQHP4J7fT3CSSN6UAqqc3wvr5uw-n68z5PV3yTbxj1JM2-eI0WX500ojMi3eVHdNsj1zkLBqDGpxlPrMRklRXxg5eoJJedRkUzdMUdbRHXbO70oAMuQdPrCMh1-vMxL6Re1R0sIiXRwzIV1xhhmKXX4sMMBItvHKv6xUNCD6Eh8u0KC1PH4kaMM6oXMK4TlXGcJxG4uUy1yan2gHUz7JWZ9jZ9InYOGjqxyQ4aJUap3m6lEDwDA5_FIL8hnlm2NSoI_CtFIZLbs90h1XUbYSGmunfUPN_vdWC4q7DnJsuSeLuoO4uaAi7OwdO9u2EF9h8qP915=w708-h943-no

The scanner is nothing special, basically a code reader made out of a PDA, those machines do not have super diagnostic capability, probably a 94 machine, think of the diagnostic capability in Cars in 94, Ford was probably still using the analog analizer to count out codes.

FByv-6_sprqKOJEPnWY2YomyP7eKOXDGj-j_MxgsAGGwsuEae3sncLkbbkmc7ph3YnIYpSKnWt7BBP7BiGexcLJ8RQSdnyv-ZlpQCpE7UMeYg6zV3oz7zhM6XMNm3mpuNdfISo1jfbPugqbI-mWPjquioi_WBpjiwsHyzD3vMq-AKTwiYeOGTd88QiESGHU6Cy7RNSnnoi6b4H4o8Pv9rS0vS2P10z1s5pURbEww35b_XWI9YfRuNJGWXWjwpDBUsoHSyRq572zU2XFulHxe8dtUO1xs78kgIMlmHuDrmU6p32Zp269aFtj2OCoIUsykhjDUAEomoA8la80Dmqcr05VYIYX7M_mLnR7f0aM2ALTTxz2QsMMVHQ6BbgzRubKo0iIAKNb0i_HfJ2P-uuuJyvXEsS0LBV64Aiqxb9hRY9s914SMoKl6eJO91tdwxzk2Bri2iJOkFQLZXex6YYbZfyqj4CWvL2bTEg6OxmB4X7q8cbrJpYJj09OkQ89LMxXjM4cbCZUtEUcSPchwaHqgRjXC20lqT555VRIy_0TG3VcIFvhf_LIehC94zIY8kq9kA9VgSbrX_fuG9AftVS_Vv8gPwUsXQKwRrYX0IzJUhXtqoSoepva29congIVZLTCx6K6_9BJJNamZBkaLjDB_qSqLZMBsIYGutQunImZhHj3Cl4D6gRSxLkSd-cdb=w1258-h943-no

To bad I was just in Maryland, stayed on the patomic river in harpers ferry if memory serves me right.

natemarine · Apr 23, 2020

dieseldog5.9 said:
My Experience with aftermarked sensors can be summed up by this box, notice the shiny DP Sensors, and the shiny angle sensors, all junk the problem is you will chase your tail after you put a new after market sensor in. I believe the new DP sensor is $1000 from Deere.

Setting the Angle Sensor take a special harness

The scanner is nothing special, basically a code reader made out of a PDA, those machines do not have super diagnostic capability, probably a 94 machine, think of the diagnostic capability in Cars in 94, Ford was probably still using the analog analizer to count out codes.

Ok, I just ordered the dr. zx, it is supposed to read the ex-3 models. It comes with wire to connect, and cd to download on a laptop. Where do I plug this in last time I had the Deere dealership come out to try he couldn't find where to plug in and I'm not sure either. I'm hoping the aftermarket stuff I bought is good. It is from a supplier for excavator parts inside usa. But they were china prices to be honest. Also, I had no idea all of these sensors etc. had to be calibrated in some way. We literally replaced the parts as we saw them. I am going to wait until I receive the second solenoid and try it with two knew ones because that is what really had an affect on the performance and it's the best I've got right now. Then I will test it out again. I called the hitachi dealership this morning because I was worried about this subject, and he said in a round about way that there's no real difference with aftermarket parts.....he said genuine parts are required to maintain warranties. so alot of mixed information for me lol.

I'm beginning to think I had two bad solenoids, I'm not sure if the machine would function like that. I'll know in a couple days.

1. Will the dr. zx program read this machine properly?
2. Will it tell us what is going on? It says it checks electrical and hydraulic settings, etc.
3. Will this tool work for setting/changing new dp sensor and angle sensor? (these were installed, no adjustments...No real change)
4. Where do I plug it in. (I have a shop manual (book) coming I'm hoping this will assist us.)

To bad I was just in Maryland, stayed on the patomic river in harpers ferry if memory serves me right.

excavator · Apr 23, 2020

Look down along side the right side of the seat towards the back of the cab. You will find a square 4 terminal plug, flat terminals. It's just hanging there and sometimes is a bit hard to find.

rgl726 · Apr 23, 2020

we will be tempted to buy the replacement because of the price difference but it is always a waste of money either. I have a lot of that china solenoids. then I learned my lesson after a lot of money wasted.

continuity checks for the wiring is a MUST to do. working parts is useless without doing this.
dr zx will accelerate this task. you can see all the sensors reading on dr zx. and can start tracing for the sensor lines that is not have reading. for the actuators(solenoids) needs line voltage check. pump solenoid is ground controlled by the computer so live 24v is always constant via a relay which is also controlled by the computer.

use the genuine parts specially the 2 pump solenoid.

computer power blinking does not mean its working.

quick parts problem elimination is by installing the suspected bad parts to a normal working machine but we don't have all the resources to do that.

angle sensor should be set up properly with dr. zx or manually by a tester.

dieseldog5.9 · Apr 24, 2020

I know when the light is not blinking it is a problem, had a customer working on his own machine short out the computer.

LACHAU · Apr 24, 2020

natemarine said:
I have no manual but I just ordered a hard copy I hope its the right thing it is a technical shop manual for hitachi 120-3 it supposed to be here next week but any advice you could give to keep us going would help

Hope that is helpful. It's EX120-3 full Technical manual.

http://www.mediafire.com/file/o8dxek1yvr4h5tm/EX120-3_T135E-00_Technical_Manual.pdf/file

excavator · Apr 24, 2020

natemarine said:
I'm hearing mixed reviews.... is there a problem with after market parts? Dealership wants way too much money for them, what is the difference? the dealer said its the same but it affects warranties, I dont have a warranty lol.
pilot pressure pump was just replaced I'm assuming the pressure is good. Have checked all the wiring and harnesses for frayed wires or wear but not for continuity. It has been a problem to get shop manuals and specs because it is gray market machine. I just found a guy with the john deere 490 e program on his computer but I'm thinking about ordering dr. zx (mine is ex)

Did not adjust angle sensor tried to put it in exact position as the other (do this by ear? using laptop? please advise...)

Both computers (on top of eachother behind seat) had flashing red lights when I checked

beyond this I don't know if pvc is functioning properly

I have tried to hired heavy equipment repair companies to fix it but they can't ever figure it out

The 490E program should work fine.

natemarine · Apr 24, 2020

Update: I was told this wasn't a big deal but thought I would run it by you guys. When searching for answers I found the hyd temp sensor on the bottom of the hyd tank was definetly messed up. The wire broken and sensor wire end, sensor may be ok. A friend / diesel mechanic said no big deal just was hyd temp sending unit.... but is there more to it?

excavator · Apr 24, 2020

To be honest with you, I rarely see a hyd. temp sensor working on the older machines. Should not cause a problem.

Granthendrickson · Apr 26, 2020

LACHAU said:
Hope that is helpful. It's EX120-3 full Technical manual.

http://www.mediafire.com/file/o8dxek1yvr4h5tm/EX120-3_T135E-00_Technical_Manual.pdf/file

lachau - do you have a link for the ex120-5 manual? Or is the -3 similar enough to use?

natemarine · Apr 27, 2020

Update
I have additionally replaced the pressure sensor with no change. Still waiting on second solenoid to be delivered. I have hard copies of the technical and shop manuals I have dr. zx software and data link wire with usb for laptop on the way. One of the kind members on this site connected me with the windr program and the technical manual. I don't have a laptop but I do have a brand new chromebook they say the new dr zx software is compatable I'm not sure. Are these programs the same? Is one better than the other? I'm thinking/hoping between all these we will find a true diagnosis. In all my research here it seems to me like multiple things may be malfunctioning. Anyone have any advice on which is better?

dieseldog5.9 · Apr 27, 2020

Setting the pump angle sensor with a multimeter is important, I don't think dr. Zx will accomplish that task, you need special harness, might be able to make one.

See my earlier post for the harness, also you notice in my picture an angle sensor that did not pass setup and was junk, causing major operational issues.

LACHAU · Apr 28, 2020

dieseldog5.9 said:
Setting the pump angle sensor with a multimeter is important, I don't think dr. Zx will accomplish that task, you need special harness, might be able to make one.

See my earlier post for the harness, also you notice in my picture an angle sensor that did not pass setup and was junk, causing major operational issues.

It may be same like this.

mg2361 · Apr 28, 2020

WinDr became MPDr and that is the dealer level software.

dieseldog5.9 · Apr 28, 2020

Wow, we are getting serious now, never seen it in color before, I always had to deal with this problem with the manual open on the back of a service truck with the wind blowing or the mesquitos buzzing in your ear, you think i am joking but i bet the manual has mosquitos in the pages on the shelf.

Have seen angle sensors aftermarket out of the box not pass this range test.

There was a hydraulic kit out there that got rid of all the electrical stuff on this machine and made it a full hydraulic controlled machine.

excavator · Apr 28, 2020

dieseldog, have you ever seen one of those kits actually work? I don't think I have heard of anyone who installed one say it made the machine run like it was supposed to.

Hitachi ex 120-3 hydraulic issues

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