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Hitachi Ex120 Problem

santikko

Well-Known Member
Joined
Aug 26, 2012
Messages
57
Location
finland (bad english)
check out the pvc fuse. its 1amp, and dont put there any bigger no matter how you want, you will get a toasted pvc in seconds. if its burned. when a-sensor gets really broken, it burns this fuse.
 

Andre-1

Active Member
Joined
Feb 5, 2011
Messages
38
Location
Jamaica
Hey could you recommend a chinese company where i can purchase a EPC controller for the hitachi ex120-2/ JD 490E excavator and how much did the ones you bought cost?
 

Andre-1

Active Member
Joined
Feb 5, 2011
Messages
38
Location
Jamaica
Not sure, I need to know the wiring diagrahm for the # 7 fuse VAL.c/u keep blowing a 1 amp fuse. I have already replaced the computer.

Any idea where I can get an engine controller for the ex120-2/JD 490E excavator? Other than the dealer.
 

Andre-1

Active Member
Joined
Feb 5, 2011
Messages
38
Location
Jamaica
The led on my engine controller blinks rapidly in sync with rapid blinking of the leds on the speed controls and i can also hear the speed control relay clicking with the same speed. Water got inthe unit so i think its toast. Any idea if it can be repaired or where and how nuch could i get one for.
 

santikko

Well-Known Member
Joined
Aug 26, 2012
Messages
57
Location
finland (bad english)
we fixed one which got toasted because of a too big fuse in pvc place, fixing it costed around like under ten dollars. you can open it and see if there is burned parts.
 

Eric1975

Active Member
Joined
Dec 11, 2010
Messages
30
Location
SW Washington
When your machine was cutting out, could you move the controls and nothing happen like the safety lever was pulled? This sounds like the same thing my EX200LC-2 is doing. It runs excellent when cold, but once it warms up it will start cutting out. I have to Idle the machine, then I can hear something release pressure like a valve opening or something. Then rev back up and it works fine until it cuts out again.Some days it is worse than others, seems to be worse on a hot day. I checked angle sensor and reset to 4.40 volts and still having same problem. It seems to do worse if I am really digging hard, boom up and stick in real fast at same time. Or when travelling. It seems to happen when you are demanding a lot of flow.
I narrowed down the problem with the ex120-2 cutting out when hot. It was the displacement solenoid valve, The electrical coil was crack and that was because the two oil seals behind the coil leaked and would slowly preasurize the electrical coil and expand it, then cutting out the coil circuit ( the coil is 18 ohms resistance) then the excavator would start to cut out. I fixed the seals and now its OK, but I would still like to replace the coil or solenoid. Does anyone have one ?
 

maxman

New Member
Joined
Mar 14, 2013
Messages
2
Location
down under
Looks like the same or similar problems with the 120's.
I have tested all the suggested parts and still no luck.
Has anyone had any luck with manual pump control?
thank you
 

digger_hunter

Well-Known Member
Joined
Apr 20, 2012
Messages
212
Location
Massachusetts, USA
hey guys,
Manual pump control is possible but the machine is not so quick or efficient any more. The -2's we've had have all had simmilar problems as above. The issue has most of the time been DP sensors. We bought several from China but these are C***. and go bust very very quickly indeed. The only things we got from China that have been ok are the PVC and EPC controllers, they seem to be ok. But for DP sensors, angle sensors, and high speed solenoids which what break on these machines just stick to OEM or you can get angle sensors only from Korea which are better. Korean angle sensors have been ok so far. Something i noticed on the chinese parts are that the DP sensor seals and coils are very very cheap quality and the seals cant handle the high temps. hope this info helps before anyone blows money on cheap copies!
 

santikko

Well-Known Member
Joined
Aug 26, 2012
Messages
57
Location
finland (bad english)
we took one OEM angle sensor, and one from china. in both of them, was a blue sticker which said the manufacturer and it was the same. then i opened them, it had been done of a hitachi- marked components- both of them. i dont know is the finland- dealer just ****ing with us. but we have working chinaparts now. the first angle sensor broke down for some reason, but in 2 weeks we got new one from the dealer. solenoids didnt work at first, then i took them open and cleaned up. now they work.
im not selling any parts my self, or dont even know anyone who does- im just angry for this finnish OEM seller, when we buy a 50€ part for over 600€ from them. i understand that you should get something on your pocket from selling those parts, but...
 

dthomason

Member
Joined
May 16, 2013
Messages
6
Location
idaho
Hello digfaster, i am having the same problem with my 1994 120-3. Did you ever figure out the answer? I have been reading some threads about the angle sensor, did you check this out on yours?
 

webdude

New Member
Joined
May 29, 2013
Messages
4
Location
Australia
-3 Doc
Hi. Do you still have any manuals for an EX120-2 ?
We have just bought one at auction and needs a few things doing.
Would appreciate any documentation for this machine. Operator's, service, parts, technical manuals, wiring diagrams etc.
Send to: webdude at thewebdudes d0t com.
Cheers, David.
 

val

New Member
Joined
Jul 31, 2013
Messages
1
Location
canada
-3 Doc
Hi. Do you still have any manuals for an EX120-2 ?
We have just bought one at auction and needs a few things doing.
Would appreciate any documentation for this machine. Operator's, service, parts, technical manuals, wiring diagrams etc.
Send to: webdude at thewebdudes d0t com.
Cheers, David.

If you got the manuals would you be willing to share them? :) I just bought one EX120-2 from auction to, and I look from manuals.
Thanks. Val
 

Andre-1

Active Member
Joined
Feb 5, 2011
Messages
38
Location
Jamaica
Sounds like the N sensor is not working, Check wiring to sensor on top of pump also known as the rpm sensor. Looks like a button held in with one bolt.

I tested the wire on the N sensor and not getting 5 Volts to the power wire (white wire) , wire continuity checks out ok from connector at n sensor back to engine controller . This wire goes directly to the Engine controller. Seem like a faulty engine controller what do you think? Machine is a 490E Deere and a two wire n sensor.
 

tntdozer

New Member
Joined
Feb 19, 2014
Messages
4
Location
virginia
I have an ex 120-2 that the swing and travel is extreamly slow! They will speed up some when you throw another function into relief . can anyone give me advice on what my problem is or where to start looking?
 
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