Hi all, I have a hitachi EX120-5 not sure what the problem is every now and again it starts to get very jittery sounds as if it is low on oil or air in the system if you swap the digging setting to a different one on the dash panel or even stop for a minute it comes back to itself digger has just over 6000 hrs genuine just wondering is it a big fix or has anyone seen it before thanks
Good day and welcome Suggest you check out the tank air pressure, see attached. Kind regards Uffex
If you don’t see any physical cracks in the hydraulic tank cap or the cap base or damaged O-rings maybe the filter is plugging. Cap filter part # 4251384 .
Thanks lads I see some of the studs is rung off the top valve but it is still holding pressure when you push the top of this valve you can release the pressure so it is holding I will have get new filters for it and get back to you but by the sounds of your replies it must not be anything to get worried about I’m new to the digger scene and was looking to buy a mulcher for the 120 but I just want to make sure the digger is fit for purpose first thanks again
When you say jittery do you mean pilot controls are vibrating or do you hear a surging or vibrating sound in machine.I know you stated when you change modes it goes away for a while. If you shut engine off and start back up does it go away for a while then come back? Does it get worse or more frequent as machine heats up?
Good day Check the hydraulic fluid is not foaming, the strainer filter for the pumps is clean. Kind regards Uffex
sorry I was mistaken with original part #. EX120-5 hydraulic tank cap filter part # by serial number. Part # 4371823 , SERIAL NO. -056232 Part # 4437838 SERIAL NO. 056233-
There is a surging sound as if the machine is starving itself of oil now I have spoken to a guy today and he has told me that I have the wrong hydraulic fluid in it I have hydraulic 32 oil in the machine and he has told me it needs 46. It does get more frequent as the machine heats up as it doesn’t really start until machine is running for a few hours
Thanks uffex what filter is the strainer filter ?
Just read your reply and noticed what you stated about the hydraulic oil. Your EX 120-5 had Hitachi 46N full synthetic what they marketed as their 4000 hour oil. Can you tell me how much of the 32 hydraulic oil you have added to the system? Is the oil in your hydraulic oil level sight glass crystal clear or does it have a brownish look. (this will be an important clue to what My response will be.) I will not have time to reply until tonight but I will explain in detail on subject tonight.
Good day The strainer filter is on the suction line for the pumps, see 23. Kind regards Uffex
I have more than likely added around 20-25 gallons of 32 due to busting hydraulic hoses in the past 2 years as I am unsure of what age the machine acctually is I was told at the time by someone that hyd 32 was the correct oil but this obviously isn’t the case it’s no problem I can drain all of it but it has done a fair bit of work with it in it I will get a picture of the oil sight glass to show you the colour of it in the next hour or two thanks again for the help much appreciated
Got time for a quick reply, have you noticed any of the hydraulic functions acting odd especially boom down has it on cool morning not wanted to boom down than when warms up operates ok. Do you have any guess on how many hours on unit with 32 oil in it. Please send picture of monitor if it is the monitor I am thanking about we can look at some live data also.
It has more than likely ran for 150 hrs on the 32 oil maybe a bit less if I can get a video maybe of the problem occurring but it will more than likely be a week or two
I haven’t noticed any problems with the booming down when cold or warm but I think my best bet is to drain the hydraulic oil and replace with 46 and change all filters again and then go from there I have also been told it could be a faulty solenoid somewere but the advice I’ve got locally doesn’t seem to be great advice
I will post info on the oil situation later, but have you checked the oil level in hydraulic pumps splitter drive housing? The dipstick to left of housing looking at rear of pumps.
I meant looking form rear of pumps not at rear of pump sorry.
If you don't mind, go to post for Off road haul trucks on first page of posts you will see Deere 300D Series II change hydraulic oil to environmental. I have explained the process of what happens to the oil. Will save me a lot of typing. Thanks
Actual EX120-5 parts page.
No problem at all Steve I have checked this previously it’s at the correct oil level I will have a look at your other post and get back to you then I am going to start draining hydraulic fluid this evening when I’m home and change out for 46
I have the exact same situation on my EX120-5 (looks like the same model as yours) my one judders then loses power (when moving forward or back or using the boom) but doesnt happen all the time, comes and goes, but is now doing it more frequently, to me it is amost like fuel starvation, but then again i have start it, have it running and it will run quite nicely, its just when i go to move, or use the boom etc? any ideas? did you manage to get yours sorted? if so what was it?
Having worked on it, im thinking it is the injectors.
@NikinNZ if you’re thinking fuel starvation , did you check the screen in the banjo bolt at the fuel transfer pump inlet ? If you have a water separator filter there is the same banjo bolt screen at the filter inlet.
Hi Dave, Thanks for the reply, yes i did, also cleaned the water seperator, and replaced the fuel filter etc, i am going to pull the injectors and get them serviced to see if that cures it.